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There are 1597 search results for: Triangular Grids: A Review of Waveguide Analysis with Classical FIT and Some Reflections on Yee-like FIT- and FEM- Schemes
| Title: | Vector Hysteresis Modeling in Arbitrarily Shaped Objects Using an Energy Minimization Approach |
| Abstract: | It is known that proper and efficient modeling of vector hysteresis is crucial to the precise design and performance estimation of electric power devices and magnetic recording processes. Recently, discrete Hopfield neural networks have been successfully utilized in the construction of vector hysteresis models. This paper presents a novel energy-minimization Hopfield neural network approach to implement Stoner-Wohlfarthlike vector hysteresis operators in triangular sub-regions. Advantages of the approach stem from the nonrectangular nature of such operators, which could mimic major hysteresis loops as well as their implementation in the most commonly used triangular discretization subdomains. Details of the approach are given in the paper. |
| Author(s): | A. A. Adly, S. K. Abd-El-Hafiz |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 7 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1305 KB |
| Title: | Tunable Band-Notched UWB Antenna from WLAN to WiMAX with Open Loop Resonators using Lumped Capacitors |
| Abstract: | The proposed antenna in this paper is compact UWB monopole antenna with a rectangular patch consists of stepped cuts and triangular slot. A two open loop resonators are designed and added near microstrip feed line to achieve sufficient band rejection from 5.1 GHz to 6.5 GHz for avoiding interference with WLAN frequency bands. The proposed antenna has low profile and compact size, its size equals 3.2 x 3.2 cm2. It has bandwidth from 3.1 GHz to 19.3 GHz with voltage standing wave ratio (VSWR) < 2, except the undesired band of 5.1–6.5 GHz. Two-lumped capacitors are inserted in order to investigate the ability of tuning the resonance frequency of the band-notched structures from 5.6 GHz to 3.5 GHz. Finally, the layout of the proposed UWB monopole antenna with the notched band is experimentally fabricated and measured to verify the simulation results. Furthermore, the return loss and far-field measurements of the fabricated antenna exhibit good match with simulation predictions. |
| Author(s): | W. A. E. Ali, A. A. Ibrahim |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 6 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2018 KB |
| Title: | Triangular-Arranged Planar Multiple-Antenna for UWB-MIMO Applications |
| Abstract: | A triangular-arranged (TA) planar multiple-antenna is proposed. It consists of three ultra-wideband (UWB) planar monopole antenna elements, with the centers and the ports of the elements arranged at the vertexes of two regular triangles, thus the polarization of each element is 120° different. The performance of the TA multiple-antenna is investigated by simulation and measurement, and the measured results agree with the simulated ones in reasonable precision. Within the ultra-wide bandwidth of 3.4 GHz – 12 GHz, the return loss at each port is better than 10 dB, and the isolation between any two ports is higher than 20 dB. Furthermore, good omni-directional radiation pattern is obtained over the interesting frequency band. A linear-arranged (LA) threeelement multiple-antenna is compared with the proposed TA antenna. Comparison between the TA antenna and the LA antenna validates the advantages of the proposed one, which consequently is suitable for UWB-MIMO applications. |
| Author(s): | X.-S. Yang, S.-G. Qiu, J.-L. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 1 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 2389 KB |
| Title: | Triangular Ring Patch Antenna Analysis: Neuro-Fuzzy Model for Estimating of the Operating Frequency |
| Abstract: | In this study, a neuro-fuzzy (NF) analysis method is suggested for the estimation of the operating frequency of triangular ring patch antennas (TRPAs) that operate at ultra high band applications. Although the analysis of regular-shaped patch antennas (PAs) such as rectangular, triangle, and circle is easy, analysis of irregularly shaped patch antennas is difficult and time consuming. Here, this great effort and time has been eliminated by using an artificial intelligence technique such as NF. To create a data set for NF, 100 TRPAs with different physical and electrical properties (L, l, h, and er) are simulated by using an electromagnetic simulator program. The currency and accuracy of the proposed approach is then confirmed on the measurement results of a prototype TRPA fabricated in this study. The results of NF model are compared with the simulation/ measurement results and previously the method published in the literature. |
| Author(s): | A. Kayabasi |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 11 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 4601 KB |
| Title: | Triangular Patch Yagi Antenna with Reconfigurable Pattern Characteristics |
| Abstract: | A pattern reconfigurable Yagi patch antenna is proposed. The antenna is composed of three triangular microstrip patches, i.e., one driven patch and two parasitic patches. By controlling switches, which are installed on the parasitic patches, the radiation pattern of the antenna can point to three different directions, covering an elevation range from -61° to +63° in the E-plane. The simulated and measured results are presented and they agree with each other in reasonable precision. |
| Author(s): | J. Zhang, X. S. Yang, J. L. Li, B. Z. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 11 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 899 KB |
| Title: | Triangular Grids: A Review of Waveguide Analysis with Classical FIT and Some Reflections on Yee-like FIT- and FEM-Schemes |
| File Type: | Conference Paper |
| Issue: | Volume: Time Domain Numerical Modeling Beyond FDTD Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 738 KB |
| Title: | Triangular Grids: A Review of Resonator and Waveguide Analysis with Classical FIT and Some Reflections on Yee-like FIT- and FEM-Schemes |
| Abstract: | Abstract—The focus of this paper is on the solution of Maxwell's equations on triangular orthogonal grids for timeharmonic elds in cylindrically symmetric resonators and general time dependant elds in length-homogeneous waveguides, respectively. The method is based on the Finite Integration Technique (FIT) [1], [2]. The 2D simulation on a structured triangular grid combines the advantages of FIT, as e.g. the consistency of the method or the numerical advantage of banded system matrices, with the geometrical exibility of noncoordinate grids. FIT on triangular grids was rst introduced in [3], [4]1. This paper presents a review describing the underlying theory in FIT operator notation rst introduced in [2] and puts this classical approach for FIT on triangular grids in relation to actual research in the eld. |
| Author(s): | URSULA VAN RIENEN, URSULA VAN RIENEN |
| File Type: | Journal Paper |
| Issue: | Volume: 19 Number: 1 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 973 KB |
| Title: | Transmission through an Arbitrarily Shaped Aperture in a Conducting Plane Separating Air and a Chiral Medium |
| Abstract: | The analysis of chiral materials has been an important subject in computational electromagnetics. In this paper, the method of moments technique is used to solve the problem of transmission through an arbitrarily shaped aperture separating air and a chiral medium. The aperture is in an infinite PEC (perfect electric conductor) plane. The excitation is assumed to be a plane wave in air. The equivalence principle is used to replace the aperture with a conducting surface with an equivalent magnetic current on each side of it. By enforcing the continuity of the tangential components of the total electric and magnetic fields across the aperture, coupled integral equations are obtained. The aperture has been modeled by triangular patches. The equivalent magnetic currents are approximated by linear combinations of expansion functions. The mixed potential formulation for a homogeneous chiral medium is used to obtain the electric and the magnetic fields produced by these expansion functions. The coefficients of these expansion functions are obtained by using the method of moments to solve the coupled integral equations. |
| Author(s): | S. T. Imeci, F. Altunkilic, J. R. Mautz, E. Arvas |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 7 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 747 KB |
| Title: | Transient Electromagnetic Scattering from Dielectric Objects Using Time-Domain Integral Equation |
| File Type: | Conference Paper |
| Issue: | Volume: Computational Techniques Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 197 KB |
| Title: | Transient Analysis of Electromagnetic Scattering using Marching-on-in-Order Time-Domain Integral Equation Method with Curvilinear RWG Basis Functions |
| Abstract: | In this paper, a modified marching-onin- order time-domain integral equation method is utilized to analyze transient electromagnetic scattering from arbitrarily shaped objects. The spatial and temporal testing procedures are separate, and both of them are performed with the Galerkin’s method. The curvilinear RWG basis functions are used as spatial basis functions with curved triangular patch modeling. It gives a remarkable reduction to the number of unknowns, also the memory requirement and CPU time, without sacrificing the accuracy. The use of the weighted Laguerre polynomials as temporal basis functions ensures an absolutely stable solution even in late time. Several numerical results, including the single ogive and NASA almond, are given to demonstrate the accuracy and efficiency of the proposed method. |
| Author(s): | Q. Q. Wang, C. Yan, Y. F. Shi, D. Z. Wang, R. S. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 5 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 989 KB |
| Title: | THE LINEAR-PHASE TRIANGULAR FACET APPROXIMATION IN PHYSICAL OPTICS ANALYSIS OF REFLECTOR ANTENNAS |
| Abstract: | Numerical analysis of reflector antennas uses a discrete approximation of the radiation integral. The calculation replaces the actual reflector surface with a triangular facet representation. The physical optics current is then approximated within each facet. This paper provides analytical details of the method based on the assumption of a constant magnitude and linear-phase approximation of the physical optics current. Example calculations are provided for parabolic, elliptical, and shaped subreflectors. The computed results are compared with calculations made using a constant-phase approximation. These results show that the linear-phase approximation is a significant improvement over the constant-phase approximation in that the solution converges over a larger angular region of space. This improvement can significantly reduce storage requirements and possibly execution speed. [Vol. 6, No. 2, pp. 74-85 (1991)] |
| Author(s): | W. A. Imbriale, R. E. Hodges, W. A. Imbriale, R. E. Hodges |
| File Type: | Journal Paper |
| Issue: | Volume: 6 Number: 2 Year: 1991 |
| Download Link: | Click here to download PDF File Size: 409 KB |
| Title: | The Combination of GPU and CPU Techniques to Fast Calculate High Frequency Scattered Fields from 3-D Realistic Scatterers |
| File Type: | Conference Paper |
| Issue: | Volume: 10-TE-3 Recent Advances on Electromagnetics Modeling and Simulation Techniques II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 609 KB |
| Title: | The analysis of transient scattering for rectangular incident waves using the discrete Laguerre transforms |
| File Type: | Conference Paper |
| Issue: | Volume: Higher Order Methods Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 188 KB |
| Title: | SURFACE MODELLING FOR EM INTERACTION ANALYSIS |
| Abstract: | This paper deals with the numerical modelling of the surface of a structure with a wire grid or a surface patch for Electromagnetic (EM) interaction analysis. Surface currents and fields on a wire grid model are computed using the Numerical Electromagnetics Code (NEC). The results are compared with those obtained on a triangular surface patch model using an Electric Field Integral Equation (EFIE) formulation. Simple structures such as a square plate as well as complicated structures such as an aircraft are considered. Good agreement is obtained in most cases. [Vol. 6, No. 2, pp. 38-52 (l99l)] |
| Author(s): | S. Kashyap, A. Loule, S. Kashyap, A. Loule |
| File Type: | Journal Paper |
| Issue: | Volume: 6 Number: 2 Year: 1991 |
| Download Link: | Click here to download PDF File Size: 587 KB |
| Title: | Subdividing Distorted Prisms into Tetrahedra |
| File Type: | Conference Paper |
| Issue: | Volume: Finite Element Method and Applications Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 133 KB |
| Title: | Square Shape Patch Antenna with Triangular Slot |
| File Type: | Conference Paper |
| Issue: | Volume: S10 EM Simulations using Sonnet I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 722 KB |
| Title: | Spherical Aperture-Coupled Antennas with Parasitic Element |
| Abstract: | Theory and experiment of spherical aperture-coupled antennas with parasitic elements are presented in this paper. Current distributions on slot and conformal patches are calculated using spatial domain electric and magnetic Dyadic Green's Functions (DGFs). Electromagnetic fields for such a structure have been calculated with the aid of linear Rao-Wilton-Glisson (RWG) triangular basis functions and by converting spherical DGFs to Cartesian DGFs. In order to validate the proposed method, a prototype of this antenna is fabricated and tested. The effect of parasitic element on antenna characteristics such as gain and radiation pattern is investigated. Good agreement between the results shows accuracy and high convergence speed of the presented method. |
| Author(s): | J. S. Meiguni, M. Kamyab, A. Hosseinbeig |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 12 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 476 KB |
| Title: | Solving Combined Field Integral Equations with Physics-informed Residual Learning |
| File Type: | Conference Paper |
| Issue: | Volume: S18 Advances in Integral Equation Methods Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 3968 KB |
| Title: | Slotted Triangular Monopole Antenna for UHF RFID Readers |
| Abstract: | A new compact slotted triangular monopole antenna for ultra-high frequency (UHF) radio frequency identification (RFID) applications is presented. The antenna exhibits an omnidirectional radiation pattern and has a bandwidth (BW) of more than 13%. It covers the global UHF RFID band and has a maximum gain of around 2.6 dBi. An overview of the antenna design along with the full wave simulation is provided. A prototype of the antenna is fabricated and tested. Good agreement is obtained between simulated and measured results. Moreover, the antenna is used with a UHF RFID reader in real use cases where read range and read rate with different commercial tags are used to evaluate the antenna performance. |
| Author(s): | K. ElMahgoub |
| File Type: | Express Journal Paper |
| Issue: | Volume: 1 Number: 1 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 367 KB |
| Title: | Slotted Triangular Monopole Antenna for UHF RFID Readers |
| Abstract: | A new compact slotted triangular monopole antenna for ultra-high frequency (UHF) radio frequency identification (RFID) applications is presented. The antenna exhibits an omnidirectional radiation pattern and has a bandwidth (BW) of more than 13%. It covers the global UHF RFID band and has a maximum gain of around 2.6 dBi. An overview of the antenna design along with the full wave simulation is provided. A prototype of the antenna is fabricated and tested. Good agreement is obtained between simulated and measured results. Moreover, the antenna is used with a UHF RFID reader in real use cases where read range and read rate with different commercial tags are used to evaluate the antenna performance. |
| Author(s): | K. ElMahgoub |
| File Type: | Express Journal Paper |
| Issue: | Volume: 32 Number: 12 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1842 KB |
| Title: | Slotted Triangular Monopole Antenna for UHF RFID Readers |
| Abstract: | A new compact slotted triangular monopole antenna for ultra-high frequency (UHF) radio frequency identification (RFID) applications is presented. The antenna exhibits an omnidirectional radiation pattern and has a bandwidth (BW) of more than 13%. It covers the global UHF RFID band and has a maximum gain of around 2.6 dBi. An overview of the antenna design along with the full wave simulation is provided. A prototype of the antenna is fabricated and tested. Good agreement is obtained between simulated and measured results. Moreover, the antenna is used with a UHF RFID reader in real use cases where read range and read rate with different commercial tags are used to evaluate the antenna performance. |
| Author(s): | K. ElMahgoubb |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 12 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1842 KB |
| Title: | Size-Reduced Equilateral Triangular Metamaterial Patch Antenna Designed for Mobile Communications |
| Abstract: | A size-reduced equilateral triangular metamaterial patch antenna (ETMPA) is proposed for the 5G mobile communications. The new ETMPA is formed from a conventional equilateral triangular patch antenna (ETPA) by additionally loading triangular-shaped mushroom metamaterials. One ETMPA is experimentally demonstrated. It is shown to resonate at 3.488GHz. The side length is only 0.483λg, which is much smaller than that for a conventional ETPA with a length of 0.66λg. Despite its compactness, the ETMPA has an acceptable bandwidth of 2.1% and antenna gain of 6.3dBi in measurement. These performances make the compact ETMPA proposing to be used in the wireless communications at 3.5GHz. |
| Author(s): | G. Dai, X. Xu, X. Deng |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2135 KB |
| Title: | SIMPLIFIED ANALYTICAL SOLUTIONS FOR MAGNETIC SIMULATION OF NEURONS |
| Abstract: | Strong pulses of magnetic field are used to stimulate peripheral nerves and motor neurons in the cerebral cortex,. Such stimulation is used in neurology for numerous diagnostic purposes. The electric field induced in tissue along the neuron and its spatial derivative are the parameters determining neural response. Another important parameter influencing the efficiency of stimulation is the inductance of a coil producing the magnetic field, as it defines the current time derivative for a given pulse generator. For arbitrarily located coils of arbitrary shapes, a semi-analytical solution is presented to calculate spatial distributions of the electric field and its spatial derivatives in a semi-infinite tissue model. Analytical solutions are given for coils composed of linear segments parallel or perpendicular to the air- tissue interface. Expressions for inductance of coils having suitable geometries for neural stimulation are derived. Coils can be optimized for stimulation of nerves at given orientation and distance from the air-tissue interface. In the optimization, coil dimensions and shape are considered as they affect both the induced field and inductance. A quadruple coil consisting of triangular sections appears to offer some advantages over other shapes for stimulation of shallow nerves. For deep nerves spaces quadruple square and three-dimensional coils are preferred. Analyses described are useful in evaluating various options, gaining an insight into the physical phenomena involved, and as the first step before undertaking a numerical analysis of models more closely representing the tissue electrical and geometrical complexities. [Vol. 7, No. 2, pp. 162-178 (1992), Special Issue on Bioelectromagnetic Computations] |
| Author(s): | Karu P. Esselle, Maria A. Stuchly, Karu P. Esselle, Maria A. Stuchly |
| File Type: | Journal Paper |
| Issue: | Volume: 7 Number: 2 Year: 1992 |
| Download Link: | Click here to download PDF File Size: 914 KB |
| Title: | Simple and Efficient Design of Reconfigurable FSS with Triangular Patch Elements |
| File Type: | Conference Paper |
| Issue: | Volume: S13 Advances in EM Modeling and Optimization From Theory to Applications II Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 307 KB |
| Title: | Resolution of 2D Time Domain Electric Field Integral Equation: Novel formulation of RWG associated to Laguerre Polynomials |
| File Type: | Conference Paper |
| Issue: | Volume: S20 Integration Equation Techniques & Applications Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 267 KB |
| Title: | Research on Quasi-isotropic Radiation of Small Circular Arc Antenna |
| Abstract: | The radiation characteristics of circular arc antennas are studied by applying the method of moments (MoM) to solve the electric field integral equation (EFIE). Based on the triangular current distribution of small circular arc antennas, the analytical expression of radiation fields of circular arc antennas is derived. It is found that the circular arc antenna is equivalent to a superposition of an electric dipole and a magnetic dipole, resulting in near isotropic radiation pattern. Finally, both MoM and CST simulations show that the small arc antenna can realize the near isotropic radiation pattern. |
| Author(s): | H. Liu, J. Liu, X. Nie, J. Song, Z. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 9 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 2039 KB |
| Title: | Receiver Sites for Accurate Indoor Position Location Systems |
| File Type: | Conference Paper |
| Issue: | Volume: Technologies for Ultra-Wideband Communication Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 230 KB |
| Title: | RCS Estimation of 3D Metallic Targets Using the Moment Method and Rao-Wilton-Glisson Basis Functions |
| Abstract: | This work deals on the estimation of the radar cross section (RCS) of five three-dimensional conductive objects: the metallic sphere, NASA almond, single ogive, double ogive and conesphere, using the Moment Method. The Rao-Wilton-Glisson (RWG) basis functions were used to expand the surface current of targets inside the Electric Field Integral Equation (EFIE). Triangular domains of RWG basis functions were constructed using MATLAB tessellation capabilities and a MATLAB code was developed and run to solve the electromagnetic scattering problem. As a result five RCS graphs, one for each target, were obtained. The accuracy of the program was validated by comparing the obtained results with those reported in the Literature. |
| Author(s): | G. K. Carvajal, D. J. Duque, A. J. Zozaya |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 5 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 474 KB |
| Title: | Preconditioning Effect of Multiple-Scattering-Based Macro Basis Function Approach |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Integral Equation Methods Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 324 KB |
| Title: | Performance analysis of MoM patch antenna simulations - RWG basis functions |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Computational Techniques for System Design Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 1009 KB |
| Title: | Patch Antenna with Triangular Slitted Corners |
| Abstract: | In this paper, a microstrip patch antenna with triangular slits was designed, simulated, fabricated and tested. The proposed patch antenna, with operating frequency of 9.5 GHz, is targeted. Simulation is carried out using Sonnet Suites. Antenna has 9.68 dB gain at 9.5 GHz with corresponding reflection coefficient of -19 dB. Proposed antenna introduces size reduction for patch antennas. The measurements of the fabricated patch antenna well corroborate the simulation results. |
| Author(s): | A. Elakas, G. A. Irmak, M. Sencan, S. T. Imeci, T. Durak |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 2 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1586 KB |
| Title: | New Basis Functions for the Electromagnetic Solution of Arbitrarily-shaped, Three Dimensional Conducting Bodies Using Method of Moments |
| File Type: | Conference Paper |
| Issue: | Volume: MoM and Applications Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 221 KB |
| Title: | New Antennas Based on Triangular Patch as a Solution for RFID Application |
| Abstract: | This paper covers the design of a new antenna for RFID applications at microwave frequencies. Five antennas are studied. The first three structures are inspired from a triangular patch, whereas the fourth and the fifth are inspired from a Sierpenski fractal antenna. The size reduction is more than 80%, which explains the utility of the proposed antennas. |
| Author(s): | A. Ferchichi, N. Sboui, A. Gharsallah, H. Baudrand |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 3 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 477 KB |
| Title: | Multiband Multipolarized Planar Antenna for WLAN/WiMAX Applications |
| File Type: | Conference Paper |
| Issue: | Volume: S19 Finite-Difference Time-Domain Method: Theory and Applications Number: Year: 2015 |
| Download Link: | Login To Download (For Members) File Size: 232 KB |
| Title: | Modeling of Surface Roughness Effects on the Performance of Rectangular u-Coaxial Lines |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Finite Element Technique and its Applications Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 466 KB |
| Title: | Modeling Corner Singularities in Triangular Cells with Hierarchical Bases |
| File Type: | Conference Paper |
| Issue: | Volume: Higher Order CEM: Development and Applications Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 475 KB |
| Title: | Miniaturized Wideband Circularly Polarized Triangular Patch Antennas based on Characteristic Mode Analysis |
| Abstract: | A miniaturized, wideband circularly polarized (CP) antenna based on coupled triangular patches is presented. Initially, two identical triangular patches with shorting pins are placed close to each other in a perpendicular orientation. Hence, a pair of orthogonal modes can be produced based on the coupled resonators. Under the characteristic mode analysis (CMA), it can be found that the 90◦ phase difference is achieved by modulating gap distance and shorting pins numbers. Both the shape of triangle patches and shorting pins contribute to the miniaturization. To further improve the AR bandwidth, a third patch is added to form a new mode. Thanks to the triple modes produced by the three patch elements, two AR minima are constructed to broaden the AR bandwidth. With this compact arrangement and shorting pins, a miniaturized wideband CP patch antenna with a 5.2% AR bandwidth is successfully implemented. The overall size of the antenna is merely 0.34λ0×0.33λ0×0.046λ0. |
| Author(s): | T.-L. Yang, X. Zhang, Q.-S. Wu, T. Yuan |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 10 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 6449 KB |
| Title: | Miniaturized Microstrip Lowpass Filter with Ultra-Wide Stopband |
| Abstract: | A new microstrip lowpass filter with compact size and ultra-wide stopband is presented. Using triangular patch resonators and butterfly resonator with four 45° radial “wing” patches, the introduced filter can successfully realize compact design and ultra-wide stopband. To further reduce the circuit size of the filter, the meander transmission lines are also adopted in the design. A demonstration filter with 3 dB cutoff frequency at 1.6 GHz has been designed, fabricated, and measured. Measured results show that the lowpass filter has an ultra-wide stopband bandwidth of 153.9 %, which is able to suppress the 11th harmonic response. Furthermore, it also has a small size of 14 ? 15 mm2, which corresponds to 0.114 ?g ? 0.122 ?g, where ?g is the guided wavelength at 1.6 GHz. |
| Author(s): | Y. Dou, J. Wang, H. Cui, J. L. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 7 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 805 KB |
| Title: | Microstrip Patch Antenna with Triangular Slits |
| File Type: | Conference Paper |
| Issue: | Volume: S57 Design Simulation and Build Microwave Devices using Sonnet Suites Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 420 KB |
| Title: | Low-Profile Broadband Top-Loaded Triangular Antenna with Folded Rim |
| Abstract: | This paper presents the impedance matching technique and the bandwidth characteristics of a low-profile top-loaded triangular antenna with oblique shorting pins. The folded rim is arranged at the edge of the finite ground plane. The bandwidth diagrams for various antenna heights, finite sizes of the ground plane, and the widths of the folded rim are obtained through the moment-method simulation. The maximum bandwidth of 43 % is achieved with 0.05 ? height. For the low-profile configuration, the bandwidth of 17 % is obtained with 0.03 ? height. |
| Author(s): | N. Michishita, W. J. Kim, Y. Yamada |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 2 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 991 KB |
| Title: | Isosceles Right Triangular Waveguides |
| File Type: | Conference Paper |
| Issue: | Volume: 2-4-B Novel Antenna Design and Analysis Method for Remote Sensing and Other Related Applications Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 341 KB |
| Title: | Improper Integrals Calculations for Fourier Boundary Element Method |
| Abstract: | This paper presents a method of regularization for the numerical calculation of improper integrals used in different formulations of Boundary Element Method (BEM). The main attention of the readers we would like to focus on Fourier Formulation of BEM. The singular integrals arise when for discretization the elements of a higher order than zero are used. Very often in the Diffusive Optical Tomography for infant head modeling, triangular or square curvilinear boundary elements of the second order are used [12,14], hence, our interest in the subject of effective and accurate calculation of singular integrals. Even for the classical formulation of BEM such a problem is extremely difficult [1]. Some authors believe that the practical application possesses only flat triangular boundary elements of zero-order, and although there is some truth in this statement, the elements of the second order show a significant advantage [10,12] in Diffusion Optical Tomography (DOT) for example. This issue becomes even more interesting when we deal with the Galerkin BEM formulation offering the possibility of matrix of coefficients symmetrisation, which has fundamental importance for inverse problems. This matter becomes critical when we start to consider the Fourier BEM formulation, introduced by Duddeck [5]. His approach provides the possibility of a solution in the case which has no fundamental solution. The light propagation, which is described by the Boltzmann equation (see Arridge [2]) is such a case. Currently and most commonly, the Boltzmann equation is approximated by the diffusion equation in strongly light scattering media [10]. In the author’s opinion, the problem of numerical integration of improper integrals has not yet been fully exhausted in the classic and Galerkin BEM formulation but the Fourier BEM formulation still expects the proposals of the effective solutions. Such an offer we would like to present in this paper. |
| Author(s): | J. Sikora, K. Polakowski, B. Panczyk |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 9 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 2000 KB |
| Title: | High-order Chebyshev-based Nystrom Methods for Electromagnetics |
| File Type: | Conference Paper |
| Issue: | Volume: S05 Locally Corrected Nystrom Method and its Applications Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 3313 KB |
| Title: | High Frequency Radiation Pattern Analysis for Antennas Mounted on Material-Coated Conducting Platforms of General Shape |
| File Type: | Conference Paper |
| Issue: | Volume: Higher Order Methods Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 159 KB |
| Title: | Hierarchical Vector Basis Functions for Meshes with Hexahedra, Tetrahedra, and Triangular Prism Cells |
| File Type: | Conference Paper |
| Issue: | Volume: 30 Years of RWG Basis Functions Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 96 KB |
| Title: | Hierarchical Divergence-Conforming Basis Functions for Meshes with Hexahedra, Tetrahedra, and Triangular Prism Cells |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Integral Equation Methods Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 176 KB |
| Title: | Genetic-Algorithm Optimization of an Array for Near-Field Plane Wave Generation |
| Abstract: | An alternative approach to the design of an array antenna to be used to generate plane waves in the near field is presented. The original array was designed on the basis of a triangular grid of seven elements arranged in a hexagon, to minimize the number needed to achieve approximately uniform illumination of the test zone, under the assumption of isotropic element radiation patterns. In the alternative approach, a genetic algorithm was used to discover more economical distributions of elements which could still generate acceptable approximations to a plane wave zone. It was found that considerable simplifications from the 'common sense' approach were possible. |
| Author(s): | Neil N. Jackson, Peter S. Excell, Neil N. Jackson, Peter S. Excell |
| File Type: | Journal Paper |
| Issue: | Volume: 15 Number: 2 Year: 2000 |
| Download Link: | Click here to download PDF File Size: 9694 KB |
| Title: | Gain-Enhanced Wideband Circularly Polarized Antenna with a Non-Uniform Metamaterial Reflector |
| Abstract: | In this paper, a gain-enhanced wideband circularly polarized (CP) antenna with a non-uniform metamaterial (NUM) reflector is presented, which is composed of a modified wide S-shaped slot antenna and a NUM reflector. To achieve a wideband CP operation, a modified S-shaped slot is fed by an L-shaped microstrip feedline that ends with a triangular patch to improve axial ratio (AR) bandwidth and impedance bandwidth. A NUM reflector composed of rectangular metal units with different sizes is employed and its units are unevenly distributed. The proposed CP antenna is designed, fabricated, and measured. The measured results show that the impedance bandwidth covers 3.0-6.0 GHz (66.7%) and a 3-dB AR bandwidth covers 3.1-5.6 GHz (57.4%). A peak gain of 6.0 dBi is obtained at 3.8 GHz by using the reflector. The advantages of the proposed antenna are the simple structure, high gain, and broad CP bandwidth. |
| Author(s): | B. Qiu, Y. Xia, Y. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 3 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 1400 KB |
| Title: | Fast EM Scattering Analysis for the Hard Targets in a Layered Medium by Using the Hierarchical Vector Basis Functions |
| Abstract: | This paper presents an efficient algorithm combining a higher order method of moments (MoM) with the adaptive cross approximation-singular value decomposition (ACA-SVD) algorithm for the threedimensional perfect electric conductor (PEC) targets located in a planar layered medium. An efficient set of hierarchical divergence-conforming vector basis functions based on curved triangular mesh is used to expand the induced surface electric current density on the metal surface of the target in layer medium. A three level discrete complex images methods (DCIM) is applied to efficiently obtain the closed form spatial Green’s functions. To be able to solve the electrically large problems, the ACA-SVD algorithm is proposed to accelerate the matrix-vector multiplication and reduce the memory requirements when the corresponding matrix equation is solved by a Krylov-subspace iterative method. The electromagnetic scattering from the practical model of hard targets buried in a lossy medium is analyzed in this paper, and numerical examples demonstrate the accuracy and efficiency of the proposed technique for the electrically large scattering problems in layered medium. |
| Author(s): | L. Zha, R. Chen, T. Su |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 11 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 595 KB |
| Title: | Evaluation of the Contour Integral on Curved Edges in Time Domain Equivalent Edge Currents |
| File Type: | Conference Paper |
| Issue: | Volume: S03 Advances in Curved Patch Modeling Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 618 KB |
| Title: | EM Analysis of PEC Object above Halfspace by Using Higher-Order Hierarchical Vector Basis Functions |
| File Type: | Conference Paper |
| Issue: | Volume: 4-P4-A Electromagnetic Thoery and Computational Methods Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 550 KB |
| Title: | Electromagnetic Transmission Through an Aperture in a Conducting Plane Between Air and a Chiral Medium |
| File Type: | Conference Paper |
| Issue: | Volume: Guided Waves in Non-Standard Media Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 85 KB |
| Title: | ELECTROMAGNETIC SCATTERING BY AN ARBITRARILY SHAPED SURFACE WITH AN ANISOTROPIC IMPEDANCE BOUNDARY CONDITION |
| Abstract: | The problem of electromagnetic scattering from arbitrarily shaped, imperfectly conducting surfaces that can be represented by an anisotropic impedance boundary condition is solved numerically using the electric field integral equation and a triangular patch model for the surface. The anisotropic impedance boundary condition function is described by a constant surface dyadic within each triangular face. The procedure is validated by comparison of numerical results obtained with the triangular patch model with body of revolution model results for problems involving scattering by spheres and cylinders having uniform or anisotropic impedance boundary conditions. [Vol. 10, No. 3 (1995), Special Issue on Advances in the Application of Method of Moments to Electromagnetic Radiation and Scattering Problems, pp 93-106] |
| Author(s): | Allen W. Glisson, Mark Orman, Frank Falco, Donald Koppel, Allen W. Glisson, Mark Orman, Frank Falco, Donald Koppel |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 3 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 1128 KB |
| Title: | Electromagnetic Coupling Analysis of Transient Excitations of Rectangular Cavity through Slot using TD-EFIE with Laguerre Polynomials as Temporal Basis Functions |
| Abstract: | This paper presents an electromagnetic coupling analysis of transient waves excited a rectangular cavity containing an interior scatterer coupled to an external scatterer through a slot. Based on the equivalence principle, time domain integral equations are established by enforcing the boundary conditions on the internal and external scatterers, the slot and the cavity walls. The method of moments is applied in space and time domains to solve the developed system of integral equations. The unknown coefficients of the electric and magnetic currents are approximated by the triangular piecewise functions associated with Dirac function as space basis. To obtain accurate and stable solutions, the Laguerre functions are used as temporal basis. Numerical results involving the coupling effects between the cavity components are investigated. The numerical results are found to be in good agreement with EM theory and literature. |
| Author(s): | D. Omri, T. Aguili |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 10 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1645 KB |
| Title: | Electric Field Distribution in a Biological Cell for Various Electrode Configurations-A Simulation Study |
| Abstract: | Electroporation or electropermeabilization (EP) is a non-viral physical process of inducing and/or increasing permeability of biological membranes by the application of high intensity and short duration electrical pulses. The resulting high field strength in the membrane can lead to the formation of regions of increased permeability, often called pores that allow transmembrane transport of macromolecules, such as DNA and chemo drugs. The efficacy of EP depends on a number of parameters, such as electric field strength, duration, number of pulses, size of target cell, and type of drug or DNA to be fed, to mention a few parameters. While electric field strength, duration, and number of pulses are the dominant parameters for the electroporation effect, the electric field distribution also depends on the shape, the size, and the material of electrodes used. The various electrodes used in practice are the parallel plate electrodes, the needle electrodes, the needle array electrodes, and the caliper electrodes. Both six needle array and parallel plate electrodes were used in the skin cancer trials. The electric field distribution varies with the type of electrode. The choice of electrodes depends upon the type of application. For example, parallel plate electrodes produce good results in human clinical trials and the distance between the electrodes can be easily varied. Needle electrodes are the simplest, but due to their configuration, the field distribution is highly nonlinear; there is higher field strength around the needle tip. That is one of the reasons for using multiple needles or needle arrays to make the field distribution as uniform as possible. It is of practical interest to study the electric field distribution of various electrodes to make a more informed choice of which electrodes to use. This paper presents the results of a study of the electric field distribution in biological tissues for various electrode configurations. Magwel was used in this study. For the same voltage applied, the triangular and arc electrode configuration developed the highest electric field strength. Specifically, we develop simulation results that enhance or enable the acquisition of information from cells. |
| Author(s): | M. O. Goni |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 5 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 910 KB |
| Title: | Efficient Time Integration Strategies for High Order Discontinuous Galerkin Time Domain Methods |
| File Type: | Conference Paper |
| Issue: | Volume: Finite-Volume and Discontinuous Galerkin Time-Domain Techniques Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 2163 KB |
| Title: | Efficient Evaluation of the Logarithmic Singularity on Elongated Triangles With a 16 Nodes Polynomial Quadrature |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Advances in Integral Equations and Fast Methods Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 2160 KB |
| Title: | Dual-band (28/38 GHz) Yagi–Uda Antenna with Corrugated Radiator and Triangular Reflectors for 5G Mobile Phones |
| Abstract: | A novel printed design of a Yagi–Uda antenna is introduced for dual-band operation at 28/38 GHz. A corrugated strip dipole with a capacitively end-coupled extension strip is employed as the driven element. The proposed antenna has two triangular-shaped reflectors and one director. The driven dipole is fed through a coaxial feed line constructed as three unequal length transition strips. A four-port MIMO antenna system constructed using the proposed Yagi–Uda is suggested for mobile phones. CSTr simulator is used to study the effect of the different design parameters on the antenna gain and the operating bands. Numerical and experimental investigations are achieved to assess the performance of both the single-element antenna and the four-port MIMO antenna system. It is shown that the simulation results agree with the experimental measurements and both show good performance of the single antenna as well as the MIMO antenna system. The bandwidths achieved around 28 GHz and 38 GHz are about 4 GHz and 1.4 GHz, respectively. The gain of the antenna is about 9 and 10 dB at 28 and 38 GHz, respectively. The four-antenna configuration shows radiation pattern diversity required for MIMO system. The envelope correlation coefficient (ECC) and the diversity gain (DG) are calculated and the results show that the proposed MIMO antenna system is suitable for the forthcoming 5G mobile communications. |
| Author(s): | A. E. Farahat, K. F. A. Hussein |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 10 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 14915 KB |
| Title: | Design of a Planar UWB Antenna with New Band Enhancement Technique |
| Abstract: | A planar antenna and a technique for enhancing its bandwidth for UWB applications have been proposed in this paper. The proposed antenna which has a compact structure and the total size of 30 × 22 mm2 consists of a square patch and a partial ground plane. Numerical study shows that the bandwidth of the proposed antenna can be controlled mainly by the patch size and width of the feeding line. The cutting triangular shape slots on the top edge of the ground plane help to increase the bandwidth by 43.6% (3.89 GHz). The measured -10 dB return loss bandwidth of the proposed antenna ranges from 2.95 GHz to 15.45 GHz which covers the entire UWB band. The nearly stable radiation pattern with a maximum gain of 5.9 dBi makes the proposed antenna suitable for being used in UWB communication. |
| Author(s): | R. Azim, M. T. Islam, N. Misran |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 10 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 386 KB |
| Title: | Design and Analysis of EBG Antenna for Wi-Fi, LTE, and WLAN Applications |
| Abstract: | A non-planar electromagnetic band gap (EBG) structured antenna is proposed in this paper for wireless communication applications. The proposed design consists of coplanar waveguide (CPW) fed square patch antenna embedded with triangular EBG backing on FR-4 substrate material for 2.4 GHz (Wi-Fi, LTE) and 5.2 GHz (WLAN) applications. Gain is improved from 2.8 dB to 13.9 dB by adding EBG structure in the proposed antenna and the parametric analysis is done for optimizing the antenna performance characteristics. The proposed antenna provides a maximum efficiency of 82.5% in the resonating frequencies. The prototyped antenna is having good correlation with the simulation results obtained from Finite Element Method (FEM) based Anyss-HFSS. High Frequency Structure Simulator is used to analyze the antenna parameters and the simulated and measured results are correlating well with each other with a slight change in frequencies. |
| Author(s): | P. Bora, P. Pardhasaradhi, B. T. P. Madhav |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 9 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 2284 KB |
| Title: | Compact W-Band Antipodal Fin-Line Transition from SIW to Rectangular Waveguide |
| File Type: | Conference Paper |
| Issue: | Volume: 4-1-C Passive/Active Microwave and Terahertz Devices Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 295 KB |
| Title: | Coalescing Tetrahedral TLM cells into Higher Order Elements for Improved Efficiency |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Developments and Applications with Time-domain Modeling Techniques Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 63 KB |
| Title: | Blind Separation of Human Motions Based on Independent Component Analysis |
| File Type: | Conference Paper |
| Issue: | Volume: 1-P1-A Student Paper Contest Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 625 KB |
| Title: | Beyond RWG/Galerkin Solutions of the EFIE: Investigations into Pointmatched, Discontinuous, and Higher Order Discretizations |
| File Type: | Conference Paper |
| Issue: | Volume: 30 Years of RWG Basis Functions Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 365 KB |
| Title: | Barycentric Quadrilateral Basis on Triangular and Quadrilateral Meshes for Stable Surface Integral Equations |
| File Type: | Conference Paper |
| Issue: | Volume: Fast Integral Equation Methods and Stable Discretization Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 509 KB |
| Title: | Babinet’s Principle Applied to Distributed Arrays |
| File Type: | Conference Paper |
| Issue: | Volume: S15 Antenna Arrays and Applications Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 497 KB |
| Title: | Array Pattern Reconfiguration Using Pixel Method |
| Abstract: | In this paper, the array elements are considered as pixels and their magnitude excitations are assigned to the values of 1 (i.e., active or turned ON) or 0 (i.e., inactive or turned OFF). Thus, each element either exists at its position in the considered array or not. The proposed pixel method can be applied to different planar array configurations such as square, rectangular, triangular, circular, or any other shape to achieve the required pattern reconfigurability. Moreover, by turning OFF some of the selected elements, the main beam of the array pattern can be switched to specify directions without using any phase shifters or any other RF components. Therefore, its practical implementation is simpler and cheaper than any other existing method. However, when comparing with arrays in which all their elements are turned ON, the gain of the considered arrays will be reduced when some selected elements are turned OFF. The array pattern reconfiguration using the pixel method has been designed and its parameters have been optimized using computer simulation Technology (CSTMWS), which uses the Finite Integration Technique (FIT). It’s also verified by High-Frequency Surface Structure (HFSS) commercial software (based on the FEM method). Numerical results obtained under fullwave modeling CST environment demonstrate the effectiveness of the described method. |
| Author(s): | K. M. Younus, J. R. Mohammed |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 3 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1743 KB |
| Title: | Arbitrary Shaped Homogeneous Invisible Ground Cloak |
| Abstract: | A general approach is introduced to design an arbitrary shaped invisible ground cloak with homogeneous constitutive parameters. The proposed homogenous ground cloak design method facilitates the fabrication process and achieves a variety of choices for choosing the cloak shape. In this approach, an arbitrary polygonal 2D cloak with any number of sides can be designed by dividing the polygonal cloak cross section into triangular segments and applying the proposed method on each one. The full wave simulations results confirm the idea performance, properly. Finally, a homogeneous ground invisible cloak for an object, which its contour is very similar to the lateral cross section of a car is designed and simulated to validate the capability and generality of the proposed idea. |
| Author(s): | M. Fazeli, S. H. Sedighy, H. R. Hassani |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1706 KB |
| Title: | APPLICATION OF EQUIVALENT EDGE CURRENTS TO CORRECT THE BACKSCATTERED PHYSICAL OPTICS FIELD OF FLAT PLATES |
| Abstract: | In the microwave case the physical optics (PO) method is frequently used for the analysis of complex structures which are modeled by flat plates of triangular or quadrangular shape. The study of the radar cross section (RCS) of an isolated panel, however, reveals deviations from experimental results which are due to edge diffraction effects not considered by PO. In order to correct the PO-field by an additive field term, the equivalent fringe currents (EC) of Michaeli have been used to derive the backscattering matrix of an isolated edge. By adding the matrices of the individual edges to the PO-matrix the RCS of a square flat plate with zero and finite thickness is analysed and the result is compared with measurements. The efficiency of the method is demonstrated for objects modeled by a higher number of panels and edges, namely a cylinder and a double dihedral. All computations were performed with the computer code SIG5 of the Institute. [Vol. 7, No. 1, pp. 24-47 (1992)] |
| Author(s): | V. Stein, V. Stein |
| File Type: | Journal Paper |
| Issue: | Volume: 7 Number: 1 Year: 1992 |
| Download Link: | Click here to download PDF File Size: 1217 KB |
| Title: | Analyzing PEC Scattering Structure Using an IE-FFT Algorithm” |
| Abstract: | In this paper a fast integral equation method, termed IE-FFT, is developed, analyzed and applied to the electromagnetic (EM) solution of scattering problems. The methodology is developed for the Method of Moments (MoM) solution of the Electric Field Integral Equation (EFIE) on electrically large Perfect Electric Conducting (PEC) structures. Similar to other Fast Fourier Transform (FFT) based algorithms, IEFFT uses a Cartesian grid to drastically decrease memory storage and speed up the matrix-vector multiplication. The IE-FFT algorithm employs two discretizations, one for the unknown current on an unstructured triangular mesh and the other on a uniform Cartesian grid for interpolating the Green’s function. The uniform interpolation of the Green’s function allows the fast computation of well-separated MoM interaction terms with the aid of a global FFT. Nevertheless, the coupling between near-interaction terms should be adequately corrected. The major contribution of this paper lies on the Lagrangian interpolation of the Green’s function. This not only allows simple and efficient algorithmic implementation, but also naturally suggests a rigorous error analysis of the algorithm. The efficiency of the method is based on the Toeplitz structure of the interpolated Green’s function. Therefore, it is applicable on both asymptotically-smooth and oscillatory kernels arisen in static and wave propagation problems, respectively. Through numerical simulations of electromagnetic wave scattering from a PEC sphere, the complexity of the IE-FFT algorithm is found to scale as O(N1.5) and O(N1.5logN) for memory and CPU time, respectively. Various numerical results verify the high accuracy and efficiency of the method. |
| Author(s): | S. M. Seo, C. Wang, J. F. Lee |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 2 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 595 KB |
| Title: | Analytical Evaluation of Matrix Elements of Electromagnetic Integral Equations with RWG basis Functions for Arbitrarily Oriented Pairs of Triangular Surface Elements |
| File Type: | Conference Paper |
| Issue: | Volume: S51 Integral Equation Solvers for Real-Life Applications II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 207 KB |
| Title: | Analysis of Transient Scattering From Conductors Using Laguerre Polynomials as Temporal Basis Functions |
| File Type: | Journal Paper |
| Issue: | Volume: 19 Number: 2 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 409 KB |
| Title: | Analysis and Synthesis of Equilateral Triangular Ring Microstrip Antenna using Support Vector Machine |
| Abstract: | A support vector machine (SVM) based analysis and synthesis models are presented for the equilateral triangular ring microstrip antennas (ETRMAs) that operate at ultrahigh band applications. The analysis and synthesis of irregularly shaped microstrip antennas (MAs) require complex, lengthy and time consuming mathematical procedures and artificial intelligence techniques such as SVM eliminate great effort and time. In this paper, two models based on SVM are constructed for analysis and synthesis of ETRMAs. The number of 100 ETRMAs with various geometrical and electrical parameters (L, l, h and epsilon r) are simulated in terms of resonant frequency (fr) with the aid of an electromagnetic simulator program to obtain the data set. Two different SVM models are designed to obtain the resonant frequency and slot dimension of ETRMAs by using the simulation data set. The obtaining the resonant frequency and slot size are analysis and synthesis processes, respectively. The SVM models are trained with the simulated data set of 75 ETRMAs and tested with remainders 25 ETRMAs. A prototype of ETRMA is then fabricated to verify the proposed models in this paper. The testing results of the SVM are compared with the simulation/measurement results and the models are found to be successful. Antenna designers can use the proposed models quickly and simply in analysis and synthesis process of ETRMAs without the need for complex processes. |
| Author(s): | A. Kayabasi |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 6 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2028 KB |
| Title: | An MoM Solution for Dielectric Rods of Arbitrary Cross-Section |
| File Type: | Conference Paper |
| Issue: | Volume: Guided Waves in Non-Standard Media Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 58 KB |
| Title: | An Irregular Ground Oriented Miniaturized Antenna for UWB Industrial Applications |
| Abstract: | In this paper, a new small UWB antenna for different UWB industrial applications is presented. The proposed prototype comprises of a simple structure with a modified triangular patch and a sawtooth ground plane. The electrical size of the proposed antenna is 0.15lambda× 0.13lambda×0.014lambda, at lower end frequency. The patch and ground plane is optimized and analyzed. The antenna shows 116% of VSWR<2 impedance bandwidth from 2.8 to 10.5 GHz with a peak gain of 5.6 dBi and 75% of the average radiation efficiency. The proposed design established a nearly omnidirectional radiation characteristic over the operating frequency band. The proposed antenna was successfully simulated, prototyped, and measured. The uniqueness of the proposed antenna is the miniaturization of the antenna for the UWB frequency band, which can be applied for different portable and convenient UWB applications. |
| Author(s): | M. Z. Mahmud, T. Alam, M. Samsuzzaman, A. Ullah, M. T. Islam |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 11 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2522 KB |
| Title: | An Efficient Finite-Element Time-Domain Method via Hierarchical Matrix Algorithm for Electromagnetic Simulation |
| Abstract: | An efficient finite-element timedomain (FETD) method based on the hierarchical (H-) matrix algorithm is presented. The FETD method is on the basis of the second-order vector wave equation, obtained by eliminating one of the field variables from Maxwell’s equations. The time-dependent formulation employs the Newmark-beta method which is known as an unconditional stable time-integration method. H- matrix algorithm is introduced for the direct solution of a large sparse linear system at each time step, which is a serious handicap in conventional FETD method. H-matrix algorithm provides a data-sparse way to approximate the LU triangular factors of the FETD system matrix. Using the H-matrix arithmetic, the computational complexity and memory requirement of H-LU decomposition can be significantly reduced to almost logarithmic-linear. Once the H-LU factors are obtained, the FETD method can be computed very efficiently at each time step by the H-matrix formatted forward and backward substitution (H- FBS). Numerical examples are provided to illustrate the accuracy and efficiency of the proposed FETD method for the simulation of three-dimension (3D) electromagnetic problems. |
| Author(s): | T. Wan, R. Chen, J. She, D. Ding, Z. Fan |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 7 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 1082 KB |
| Title: | An Efficient 2D/3D Hybrid DGTD Transient Analysis for Arbitrarily Shaped Anti-Pads in Power-Ground Plate-Pair |
| File Type: | Conference Paper |
| Issue: | Volume: S18 Computational Electromagnetics Advanced Algorithms and Emerging Applications I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 744 KB |
| Title: | An Adaptive and Highly Accurate FDTD Mesh Generation Technique for Objects with Complex Edge Structures |
| Abstract: | In this paper, a triangular facets based, highly accurate, and adaptive finite-difference time-domain (FDTD) mesh generation technique is presented. There are two innovations in the implementation of this technique. One is adaptive mesh lines placement method. The mesh lines are automatically set to be dense where the object has fine structure and sparse where the object has rough structure based on the incremental placement of the triangular mesh vertices. The other is ray column tracing method. Ray columns in the normal direction of the coordinate plane are employed to intersect the surface facets to make the mesh generation results highly accurate. The generating FDTD results of the numerical examples show that the proposed technique can well-restore objects with complex edge structures. The simulation results are in good agreement with the theoretical results. |
| Author(s): | C. Mou, J. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 1 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 7117 KB |
| Title: | Adding a Reproducible Airplane Model tothe Austin RCS Benchmark Suite |
| File Type: | Conference Paper |
| Issue: | Volume: S18 Numerical Methods: Validation, Errors and Accuracy Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 584 KB |
| Title: | Adding a Reproducible Airplane Model to the Austin RCS Benchmark Suite |
| Abstract: | A full-size airplane model (the EXPEDITE-RCS model) was developed as part of a benchmark suite for evaluating radarcross- section (RCS) prediction methods. To generate accurate reference data for the benchmark problems formulated using the model, scale-model targets were additively manufactured, their material properties and RCS were measured, and the measurements were validated with a surface-integral-equation solver. To enable benchmarking of as many computational methods as possible, the following data are made available in a version-controlled online repository: (1) Exterior surface (outer mold line) of the CAD model in two standard file formats. (2) Triangular surface meshes. (3) Measured and predicted monostatic RCS data. |
| Author(s): | J. T. Kelley, A. Maicke, D. A. Chamulak, C. C. Courtney , A. E. Yilmaz |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1343 KB |
| Title: | A Wideband Circularly Polarized GNSS Antenna for Satellite Platforms |
| File Type: | Conference Paper |
| Issue: | Volume: S46 Physically Reconfigurable Antennas and Arrays: Design, Modeling and Materials II Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 601 KB |
| Title: | A STUDY OF TWO NUMERICAL SOLUTION PROCEDURES FOR THE ELECTRIC FIELD INTEGRAL EQUATION AT LOW FREQUENCY |
| Abstract: | The numerical solution of the Electric Field Integral Equation (EFIE) using two different lowfrequency formulations is investigated. The two procedures are implemented for the triangular patch modeling procedure and results obtained for both methods are compared with the original triangular patch EFIE solution. The comparisons are made on the basis of the computed current values and the inverse condition number of the moment matrix. It is observed that the condition number of the matrix can be significantly different between the two low frequency formulations and that the method used to evaluate the forcing function can affect the results both in the low and high frequency ranges. [Vol. 10, No. 3 (1995), Special Issue on Advances in the Application of Method of Moments to Electromagnetic Radiation and Scattering Problems, pp 69-80] |
| Author(s): | Wen-Liang Wu, Allen W. Glisson, Darko Kajfez, Wen-Liang Wu, Allen W. Glisson, Darko Kajfez |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 3 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 841 KB |
| Title: | A Straight-Forward Method of Moments Procedure to Solve the Time Domain Integral Equation Applicable to PEC Bodies via Triangular Patch Modeling |
| Abstract: | In this work, a simple and straight-forward method of moments solution (MOM) procedure is presented to obtain the induced current distribution on an arbitrarily-shaped conducting body illuminated by a Gaussian plane wave directly in the time domain using a patch modeling approach. The method presented in this work, besides being stable, is also capable of handling multiple excitation pulses of varying frequency content incident from different directions in a trivial manner. The method utilizes standard Rao-Wilton-Glisson (RWG) functions and simple triangular functions for the space and time variables, respectively, for both expansion and testing. The method adopts conventional MOM and requires no further manipulation invariably needed in standard time-marching methods. The moment matrix generated via this scheme is a block-wise Toeplitz matrix and, hence, the solution is extremely efficient. The method is validated by comparing the results with the data obtained from the frequency domain solution. Several simple and complex numerical results are presented to validate the procedure. |
| Author(s): | S. M. Rao |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 8 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 3321 KB |
| Title: | A Simple Model to Compute Resonant Frequency of an Equilateral Triangular Patch Antenna Backed by Equilateral Triangular Cavity |
| File Type: | Conference Paper |
| Issue: | Volume: S38 EM Modeling and Applications - I Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 255 KB |
| Title: | A Second-Order Stabilized Control Volume Finite Element Method for Self-Heating Effects Simulation of Semiconductor Devices based on Triangular Elements |
| Abstract: | A second-order control volume finite element method combined with the multiscale flux approximation (CVFEM-MS) based on triangular elements is proposed to numerically investigate the selfheating effects of semiconductor devices. The multiscale fluxes are combined with a selected set of second-order vector basis functions to stabilize the discretization of carrier continuity equations with respect to triangular elements. Numerical results reveal that the proposed method is robust and accurate, even on the mesh of low-quality, where the detrimental impacts caused by the severe self-heating on the terminal currents can be obviously observed for a bipolar transistor model. |
| Author(s): | D.-M. Yu, X.-M. Pan, X.-Q. Sheng |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 5 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1344 KB |
| Title: | A Novel Switchable Double Band-Notch Antenna for Ultra-Wideband Application |
| Abstract: | A novel microstrip-fed planar monopole antenna is proposed that is miniaturized in size and provides reconfigurable band-notch properties. The antenna's impedance bandwidth is 150% for VSWR < 2 across 2.6-18.3 GHz, thus satisfying FCC's frequency requirement for UWB systems defined between 3.1-10.6 GHz. To circumvent interference issues resulting from existing nearby communications systems within the UWB operating frequency, the antenna includes an inverted open-loop triangular slot embedded in the hexagonal shaped radiation patch to realize a band-notch response between 3.1 to 3.9 GHz necessary to reject the WiMax band, and open-end resonator structures at both sides of the patch to create a band-notch response between 5.1 to 5.9 GHz, thus enabling band rejection of WLAN and Hyperlink systems. Furthermore, it is demonstrated the band-notch can be electronically controlled without compromising the antenna's characteristic features. This is achieved by strategically located PIN diodes on the antenna. |
| Author(s): | M. N. Moghadasi, S. F. Qotolo |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 10 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 753 KB |
| Title: | A Novel Ray Tracing Method of Creeping Waves on Triangular Mesh Surfaces |
| File Type: | Conference Paper |
| Issue: | Volume: 3-4-A Multi-Physics Modelling and Time-Domain and Frequency-Domain Computational Methods Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 806 KB |
| Title: | A Novel Domain Decomposition Method Decoupled Hybrid 2D/Q-2D Finite Element Method for Power/Ground Plate-Pair Analysis |
| File Type: | Conference Paper |
| Issue: | Volume: 3-MA-3 Advances in Numerical Modeling and Design Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 83 KB |
| Title: | A Novel Dielectric Loaded Vivaldi Antenna with Improved Radiation Characteristics for UWB Application |
| Abstract: | In this paper, a compact (40×50×0.8mm3) Vivaldi antenna with trapezoidal corrugation and a triangular director element is proposed for high gain performance. The exponential slot with diamond slot stub is designed to broaden the bandwidth. The measured bandwidth is 11.3 GHz from 2.9 to 14.2 GHz under the condition of Voltage Standing Wave Ratio (VSWR) less than 2. The simulated gain is 5.5-9 dBi at the full bandwidth. The measured gain is 5-7.6 dBi from 3 to 5.8 GHz. In addition, the measured group delay of the proposed antenna is around 2±0.8 ns. The simulated and measured results agree well. |
| Author(s): | H. Zhu, X. Li, L. Yao, J. Xiao |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 4 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2058 KB |
| Title: | A New UWB Slot Antenna with Rejection of WiMax and WLAN Bands |
| Abstract: | This paper presents a compact coplanar waveguide (CPW) fed ultra wideband (UWB) planar slot antenna with the characteristics of dual band rejection. The antenna consists of a rectangular slot with triangular tuning stub. The band notching of WiMax (3.2-3.8 GHz, with VSWR 68 at 3.5 GHz) is achieved by inserting a ‘U’ slot in the ground plane and band-notching of WLAN 802.11a (5.1-5.9 GHz, with VSWR 14 at 5.5 GHz) is obtained by embedding a ‘U’ type slot in the triangular tuning stub. The characteristics of the proposed antenna are studied both numerically and experimentally, and the design parameters for achieving optimal operation of the antennas are also analyzed extensively. The size of the antenna is around 28mm (L) × 21mm (W) × 1.6mm (T). The prototype of the proposed antenna is fabricated for its optimal values and tested. The VSWR, radiation pattern and gain are measured and agree well with the simulation results. The proposed antenna is simple, easy to fabricate and can be integrated into any UWB system, which can work without interference from WiMax, WLAN, and HYPERLAN/2 systems. |
| Author(s): | J. William, R. Nakkeeran |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 9 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 646 KB |
| Title: | A Mortar Element Method for the Modelling of Scattering by Penetrable Objects |
| File Type: | Conference Paper |
| Issue: | Volume: Fast Integral Equation Methods and Stable Discretization Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 673 KB |
| Title: | A General Framework for Mixed Structured/Unstructured PEEC Modelling |
| Abstract: | The paper proposes a re-formulation of PEEC modeling in terms of dual discretization of surface conductors. The result is a precise formalization of the PEEC tessellation and gives the possibility of handling general meshes, both structured and unstructured. This fact allows the use of triangular meshes only where necessary, leaving orthogonal discretization whenever possible and improving computational performances. The method, referred to as dual-PEEC, is validated by solving a structure referenced in literature and finally applied to the computation of the input impedance of a spiral inductor. |
| Author(s): | F. Freschi, M. Repetto, F. Freschi, M. Repetto |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 3 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 608 KB |
| Title: | A General Framework for Mixed Structured/Unstructured PEEC Modelling |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced EMC Modeling Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 645 KB |
| Title: | A Finite-Element Contrast Source Inversion Method for Microwave Tomography |
| File Type: | Conference Paper |
| Issue: | Volume: Efficient Solutions to Inverse Electromagnetic Problems Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 2157 KB |
| Title: | A Comprehensive 2D FE-SIBC Model for Calculating the Eddy Current Losses in a Transformer Tank-Wall |
| Abstract: | The calculation of the eddy-current losses is one of the most important aspects that must be considered in the design of transformers and electrical machines. In this paper, a comprehensive 2D finite element (FE) model for calculating the eddy-current losses in a tank-wall of the transformer is presented. The FE model takes into account the Surface Impedance Boundary Condition (SIBC). A detailed 2D-SIBC formulation in terms of the magnetic vector potential is described. The SIBC is incorporated into the FE formulation by using the Galerkin method. An axi-symmetric electromagnetic model of the transformer is solved by applying the SIBC formulation for calculating the loss intensity distribution along the vertical tank-wall. To demonstrate the validity of the SIBC formulation, the results are compared against those computed with a model based on first-order triangular elements. The advantages of using the SIBC formulation in the modeling of power transformers are highlighted. |
| Author(s): | J. M. Díaz-Chacón, C. Hernandez, M. A. Arjona |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 8 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 759 KB |
| Title: | A Comparison Among Fast Visibility Algorithms Applied to Computational Electromagnetics |
| Abstract: | This paper presents a set of fast algorithms developed for solving the visibility problem in large complex geometric scenarios. The implemented algorithms are: Binary Space Partitioning (BSP) –based on a binary tree structure- and three new ones: Trimming Method – facets which are partially occluded are trimmed –, Cone Method – a cone emerges from the point of view to discard shadowed facets – and Pyramid Method – a pyramid is used to eliminate non-lit patches – . All the proposed algorithms are tested on a pair of scenarios for determining the field of view of electromagnetic waves in order to calculate the corresponding induced currents on the surfaces. The scenarios consist of two electrically large spheres and two PEC plates respectively where the surfaces are meshed with a variable number of flat triangular patches. The first reflection contribution is calculated using Physical Optics (PO) for both cases. The results show that the computational time can be drastically reduced by assuming small percentage of error in the computed scattered fields. |
| Author(s): | J. G. Meana, F. Las-Heras, J. Á. Martínez-Lorenzo |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 3 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 597 KB |
| Title: | A Compact UWB Printed Monopole Antenna with Triple-Band Notched Characteristics |
| Abstract: | A compact triple band-notched printed monopole antenna for ultra-wideband (UWB) application is presented. By inserting two triangular-shaped notches in both sides of the ground plane of microstrip feed line, additional resonances are excited and the bandwidth is increased up to 160%. Three sharp notched frequency bands at 3.8 GHz, 5.5 GHz, and 7.5 GHz are achieved by embedding a pair of rectangularshaped slits in the ground plane and two pairs of modified bow-shaped slits in the patch. This novel monopole antenna has ultra-wide frequency bandwidth for input impedance, compact size (24 mm × 20 mm), low cost fabrication and Omnidirectional H-plane radiation pattern which makes it suitable for ultra-wideband applications. The measured results reveal that the presented triple band-notched monopole antenna is a promising candidate for UWB communication systems to avoid interference with WiMax band (3.3-3.7 GHz), some C-band (3.7-4.2 GHz), WLAN (5.15- 5.825 GHz) bands and some C-band satellite communication systems (7-8 GHz). |
| Author(s): | A. Abdollahvand, A. Pirhadi, M. R. Hosseinnezhad, H. Ebrahimian |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 4 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 2540 KB |
| Title: | A Compact High Gain Multiband Bowtie Slot Antenna with Miniaturized Triangular Shaped Metallic Ground Plane |
| Abstract: | This paper presents a new compact, high gain and multiband planar bowtie slot antenna. The antenna structure comprises of dielectric substrate, copper conducting sheet, fillet triangular-shaped slots, and a chamfered metallic ground plane. The proposed antenna model is fed with the 50 Ω standard grounded coplanar waveguide (GCPW) feedline. The designed antenna is low profile with compact dimensions of 0.379λ×0.186λ×0.012λ at 2.39 GHz frequency. Stable multi-resonant behavior of frequencies is obtained with the material selection, slots dimensions and position. Moreover, the parametric study has been carried out in order to validate the frequency tuning mechanism and impedance matching control. The novelty of designed antenna lies in high performance features which have been achieved with ultra-compact (0.039λ×0.022λ) modified triangular shaped metallic ground plane. The proposed antenna is fabricated and experimentally verified. The antenna key features in terms of return loss, surface current distribution, peak gain, radiation efficiency and radiation patterns have been analyzed and discussed. The designed radiator exhibits the excellent performance including strong current density, peak realized gain of 6.3 dBi, 95% radiation efficiency, wide fractional bandwidth of 39.5% and good radiation characteristics at in-band frequencies. The simulation and measured results are in good agreement and hence make the proposed antenna a favorable candidate for the advanced heterogeneous wireless communication applications. |
| Author(s): | Z. A. Dayo, Q. Cao, Y. Wang, P. Soothar, I. A. Khoso, G. Shah, M. Aamir |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 7 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1933 KB |
| Title: | A Compact Frequency Reconfigurable Split Ring Monopole Antenna for WLAN/WAVE Applications |
| Abstract: | A novel frequency reconfigurable dual band monopole antenna based on the triangular split ring element is proposed for wireless communications. The antenna with an overall compact size of 25×25×1.6 mm3 is designed for the operating frequencies of wireless local area network (WLAN) 2.4/5.0 GHz standard and wireless access for vehicular environments (WAVE) 5.90 GHz standard. The parametric study is carried out for tuning the upper resonant frequency. The reconfigurability between the WLAN and WAVE frequency bands is achieved by using a pair of PIN diode. The design considerations for the proposed antenna are described and the experimental results are validated. The antenna exhibits almost uniform radiation characteristics and good gain at each frequency band with the -10 dB impedance bandwidth of 44.1%, 5.8% and 10.1% at 2.45/5.30/5.90 GHz WLAN and WAVE bands respectively. |
| Author(s): | V. Rajeshkumar, S. Raghavan |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 3 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 598 KB |
| Title: | A Compact Design and New Structure of Monopole Antenna with Dual Band Notch Characteristic for UWB Applications |
| Abstract: | In this paper, a compact design and new structure of monopole antenna with dual band notch characteristics for UWB applications has been presented. The antenna consists of a triangular patch with C-shaped slot, two L-shaped and one split ring shaped parasitic backplane elements structure. By inserting three slots in the rectangular truncated ground plane as defected ground structures (DGSs), much wider impedance bandwidth can be produced, and moreover to improve the input matching quality of the antenna at all its operating bands which are spread in a vast frequency range, a modified stepped feed-line is employed. These changes much improves the antenna’s impedance bandwidth by 112% which covers the entire UWB bandwidth range. In order to generate single band notch characteristic, split ring shaped parasitic element backplane structure is utilized on the ground plane side of the substrate. In addition, by etching a C-shaped slot on the radiating patch, a dual band notch function is achieved. The measured frequency results show an impedance bandwidth of 3.15-10.78 GHz for a Voltage Standing Wave Ratio (VSWR) less than 2 with two eliminated bands placed at 3.49-3.81 GHz (320 MHz, 8.8%) and 5.24-6.22 GHz (980 MHz, 17%), which reject the WiMAX band, and Wireless Local Area Network (WLAN) band, respectively. A prototype was fabricated and measured based upon optimal parameters and experimental results show consistency with simulation results. The measured radiation patterns of proposed antenna for most frequencies are omnidirectional and this antenna as wide impedance bandwidth. |
| Author(s): | S. Hoseyni, J. Nourinia, C. Ghobadi, S. Masumina, B. Mohammadi |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 7 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2108 KB |
| Title: | A Broadband Reflectarray Antenna using the Triangular Array Configuration |
| Abstract: | A novel broadband reflectarray cell element is designed for use in several offset-fed reflectarray antennas based on square and triangular lattice. The proposed double-layer element consists of two stacked rectangular patches having two slots in non-radiating edges. Reflection phase curves are obtained by changing simultaneously the slot’s length of top and bottom patch. The designed element exhibits a large phase-shift range in excess of 360o.This wideband cell element is designed to be used in a triangular lattice that eliminates the grating lobes for wideband reflectarrays composed of unit-cell larger than half-wavelength. Two 529-element square reflectarrays and two 518-element triangular reflectarray antennas were designed and simulated using CST and HFSS, for producing 20o and 35o off-broadside E-plane beams using a 20o offset feed. The 1-dB gain-bandwidth is about 30% at the center frequency of 14 GHz, and the maximum simulated gain is about 31 dBi which is equivalent to 51.5% aperture efficiency for a 20o off-broadside reflectarray based on triangular lattice configurations. |
| Author(s): | M. Mohammadirad, N. Komjani, A. R. Sebak, M. R. Chaharmir |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 8 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 880 KB |
| Title: | 25 Years of Progress and Future Challenges in Higher Order Computational Electromagnetics |
| File Type: | Conference Paper |
| Issue: | Volume: 25 Years of Progress and Future Challenges in Applied Computational Electromagnetics II Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 179 KB |
| Title: | VERIFYING WIRE-GRID MODEL INTEGRITY WITH PROGRAM 'CHECK' |
| Abstract: | A wire-grid model of a complex surface such as an aircraft consists of hundreds of "vertex" points joined by hundreds of wires or "links". A wire antenna analysis program such as NEC is used to find the currents on the wires. The formulation within NEC imposes restrictions on the geometry of the wires, which limit the length of "segments" compared to the wavelength, the radius compared to the wavelength, the ratio of the segment length to the radius, and so forth. This paper collects these limitations together into a set of "modeling guidelines". The"integrity" of a wire-grid is its ability to represent the electrical behaviour of the continuous surface that it models. An important aspect of integrity is conformance to the "modeling guidelines". Gross errors creep into complex grids: repeated wires, omitted wires, wires of zero length. More subtle errors which violate the "modeling guidelines" can lead to incorrect current distributions and misleading radiated or scattered fields form the wire-grid when solved with the NEC code. This paper describes a program called CHECK which examines an input geometry file for the NEC program for conformance to the "modeling guidelines" by each individual wire, by wires forming junctions, and by pairs which do not join but are closely spaced. CHECK tabulates "notes", "warnings" and "errors" to aid the user in assessing the degree to which the model satisfies the guidelines. CHECK systematically finds all the guideline violations in a model. CHECK produces lists of wires for display with computer graphics to show the location of each type of problem that CHECK finds. The guideline violations found by CHECK inherently suggest improvements that can be made to the wire-grid. [Vol. 5, No. 2. pp. 17-42 (1990)] |
| Author(s): | C. W. Trueman, S. J. Kubina, C. W. Trueman, S. J. Kubina |
| File Type: | Journal Paper |
| Issue: | Volume: 5 Number: 2 Year: 1990 |
| Download Link: | Click here to download PDF File Size: 1753 KB |
| Title: | \"Introduction to Antennas\" – an antenna training DVD |
| File Type: | Conference Paper |
| Issue: | Volume: CEM for Applied Analysis and Synthesis Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 350 KB |
| Title: | \"Capacity estimation of HF ionospheric Channel\" |
| File Type: | Conference Paper |
| Issue: | Volume: Posters Session 2 Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 352 KB |
| Title: | Zooming into the Near-fields: Embedding Generalized- and Pseudo-functions in the Solution Space of Maxwell's Equations |
| File Type: | Conference Paper |
| Issue: | Volume: Mathematical Aspects of CEM Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 330 KB |
| Title: | Z-diagonalized Planewave/FD Approach for Analyzing TE Polarized Waves in 2D Photonic Crystals |
| File Type: | Conference Paper |
| Issue: | Volume: FDTD Methods and Applications Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 300 KB |
| Title: | Yee-based 3D electromagnetic algorithm for discontinuous anisotropic dielectrics with global 2nd-order error |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Finite Difference Time Domain Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 138 KB |
| Title: | X-Band Radar for Monitoring Space Debris |
| File Type: | Conference Paper |
| Issue: | Volume: S16 Advanced Technology for Radar Remote Sensing Applications Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 329 KB |
| Title: | X-Band Linear Dielectric Resonator Antenna Array Fed by Dielectric Resonator Power Divider Array |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Phased Array Modeling Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 486 KB |
| Title: | X-Band Isoflux Concentric Circular Antenna Arrays for Image Data Download from LEO Satellites to Ground Stations |
| Abstract: | A circularly polarized isoflux beam synthesized by concentric circular arrays of printed microstrip patch antennas is proposed for X-band transmission of image data from land-imaging LEO satellites to the ground stations. This beam has a wide coverage angle of about 100° of uniform illumination. The paper introduces a novel design of a compact righthand circularly polarized microstrip patch as an element for the concentric circular arrays. The patch antenna has impedance matching bandwidth of about 600 MHz and axial ratio bandwidth of about 170 MHz at 8.1 GHz. A prototype of the proposed patch antenna is fabricated for experimental measurements. The electromagnetic simulation and experimental results show good agreement. A computationally efficient particle swarm optimization (PSO) procedure is developed and applied to find the distribution of the excitation magnitudes over the array elements so as to generate an isoflux beam in all the elevation planes with circular symmetry in the azimuth planes. The phase of excitation is the same for all the array elements. The method proposed to apply the PSO reduces the computational resources to about 6.5% of those required by the conventional method of application. Moreover, the proposed iterative PSO procedure is shown to be very fast convergent. |
| Author(s): | M. A. El-Hassan, K. F. A. Hussein, A. E. Farahat, K. H. Awadalla |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 11 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1802 KB |
| Title: | Wrapping Existing Electromagnetic Code into an Object-Oriented Scripting Programming Language |
| File Type: | Conference Paper |
| Issue: | Volume: Object Oriented Computational Electromagnetics Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 151 KB |
| Title: | Women’s History Month Special Article: Interview with “Professor Ozlem Kilic” |
| Abstract: | The month of March is Women’s History Month. We all have heard and know that only a small percentage of electrical engineers are female. This percentage is even smaller for those that are experts in the field of applied computational electromagnetics. In this article, we are focusing on Dr. Ozlem Kilic, one of the well-known and established intellectuals in the field of computational electromagnetics. Dr. Kilic not only has been a role model for young students as an excellent researcher, a technical leader, and a prolific writer in this field, but also she has extensive experience in teaching and has taken many academic administration roles. |
| Author(s): | S. Noghanian |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 3 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 398 KB |
| Title: | Women’s History Month Special Article: Interview with “Professor Cynthia Furse” |
| Abstract: | In this article I had the pleasure of interviewing Professor Cynthia Furse. Professor Furse is not only an internationally well-known researcher in the field of computation and applied electromagnetics (EM), but also an innovator in modern teaching techniques, an entrepreneur, an academic leader, and a true mentor for many young professionals in the electromagnetics field. |
| Author(s): | S. Noghanian |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 3 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 796 KB |
| Title: | WLP-FDTD Implementation of CFS-PML for Plasma Media |
| File Type: | Conference Paper |
| Issue: | Volume: S19 Finite-Difference Time-Domain Method: Theory and Applications Number: Year: 2015 |
| Download Link: | Login To Download (For Members) File Size: 181 KB |
| Title: | WLAN Based Indoor Positioning in Building Halls by Using Trilateral |
| File Type: | Conference Paper |
| Issue: | Volume: S23 RF/Microwave Electromagnetics - Computational Modeling and Experiments Number: Year: 2015 |
| Download Link: | Login To Download (For Members) File Size: 309 KB |
| Title: | Wireless Propagation in Non Line of Sight Urban Areas using Uniform Theory of Diffraction |
| Abstract: | This paper describes a three-dimensional electromagnetic propagation model for signal power prediction in a non line of sight urban area located in Singapore. The model, which is implemented using the Ohio State NEC-BSC V4.2 basic scattering code and is based on ray theory and uniform theory of diffraction (UTD) takes into account first, second, and third order effects including triple reflections and diffractions. The simplified propagation model of Raffles Place, the central business district of Singapore, uses more than 360 geometrical structures and is compared with data measured at 937.6 MHz along a drive route at the site. The results from the propagation model produced reasonable agreement with the measurements showing that a simplified model using UTD can be used to simulate the gross features of electromagnetic scatter in an urban area. It is shown that use of penetrable dielectric building walls are also necessary for accurate prediction of radio wave propagation in urban areas under non line of sight conditions. It is also found that third order scattering effects can be dominant in non line of sight situations and may be necessary for accurate predictions. |
| Author(s): | G. A. Ellis, G. A. Ellis |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 3 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 126 KB |
| Title: | Wireless Power Transfer via Negative Permittivity Metamaterials as Resonating Elements |
| File Type: | Conference Paper |
| Issue: | Volume: S42 Wireless Power Transfer Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 252 KB |
| Title: | Wireless Power Transfer Using Magneto-Electric Dipoles |
| File Type: | Conference Paper |
| Issue: | Volume: S37 Wireless Power Transfer and Energy Harvesting: Advances in Modelling and Practice Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 245 KB |
| Title: | Wireless Power Transfer to Closely Coupled Loop Antennas Embedded in Concrete for Sensing |
| File Type: | Conference Paper |
| Issue: | Volume: Wireless Powering of Devices & Energy Harvesting Number: Year: 2014 |
| Download Link: | Login To Download (For Members) File Size: 235 KB |
| Title: | Wireless Energy Harvesting Using a Negatively Charged UV Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: 3-3-D Wireless Power Transfer and Harvesting Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 230 KB |
| Title: | Wireless Communication Applications of the Continuous Transverse Stub (CTS) Array at Microwave and Millimeter Wave Frequencies. |
| File Type: | Conference Paper |
| Issue: | Volume: Phased Array and Active Antennas Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 915 KB |
| Title: | Wireless Communication Antennas: Special Requirements And New Designs of Dielectric Resonator Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Poster Sessions 1 Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 108 KB |
| Title: | Wireless Body Area Networks: UWB Antenna design and Channel Modeling |
| File Type: | Conference Paper |
| Issue: | Volume: S19 Biomedical Applications Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 2905 KB |
| Title: | WIREGRID: A NEC2 PRE-PROCESSOR |
| Abstract: | WIREGRID is a pre-processor for the widely used public domain method of moments computer code NEC2. WIREGRID was developed for modelling metallic structures using a mesh of wires. In particular, it has powerful facilities for controlling the density of the mesh, permitting the same basic model to be used for different frequencies, with the code automatically generating a suitable mesh for a particular frequency. WIREGRID is not limited to generating wire meshes: it can also be usefully applied to true thin-wire modelling, for instance for Yagi-Uda and log-periodic antennas. In this paper, the basic philosophy of the code is described, and the code capabilities are detailed. Sufficient detail is presented so that the paper can serve as a reference for code users. The meshing algorithm is briefly described. An example is shown of the automatic mesh generation capabilities applied to an automobile. WIREGRID is available in the public domain via anonymous ftp; details of the ftp sites and hardware requirements are given in the appendices. [Vol. 10, No. 1 (1995), pp 31-39] |
| Author(s): | C. F. du Toit, D.B. Davidson, C. F. du Toit, D.B. Davidson |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 1 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 844 KB |
| Title: | WIRE-GRID MODELING OF SLOT ANTENNAS |
| Abstract: | The ability of a computer code to model slot antennas is investigated. A comparison of experimental and numerically calculated antenna data is presented. [Vol. 1, No. 1, pp.6-14 (1986)] |
| Author(s): | Jimmy L. Funke, Jimmy L. Funke |
| File Type: | Journal Paper |
| Issue: | Volume: 1 Number: 1 Year: 1986 |
| Download Link: | Click here to download PDF File Size: 1140 KB |
| Title: | Wire Realization of a Tapered Slot Antenna with Reconfigurable Elements |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Simulation using FEKO Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 504 KB |
| Title: | Wire Grid Moment Method (NEC) Models of a Patch Antenna |
| Abstract: | Wire grid models of an air-loaded resonant circular patch antenna are used to calculate several observable quantities. The resonant frequency, input reactance, and bandwidth are accurately calculated, but the input resistance is underestimated by the grid models due to the existence of separate currents on both the top and bottom of the measured solid patch. The Lawrence Livermore (NEC3) Method of Moments computer program was used to generage the grid models. Averge wire lengths of about 0.03 wavelengths are required for accurate results. A comparison with other studies suggests that the 0.03 wavelength segmentation may be required because the patch is close to the ground plane (0.0175 wavelengths), and/or because errors in the near field calculation are compounded by the large fraction of energy stored in the near field since the patch is a high Q resonator. |
| Author(s): | P.G. Elliot, S.T. McBride, P.G. Elliot, S.T. McBride |
| File Type: | Journal Paper |
| Issue: | Volume: 4 Number: 3 Year: 1989 |
| Download Link: | Click here to download PDF File Size: 703 KB |
| Title: | Wire Fault Diagnosis Using Time-Domain Reflectometry and Backtracking Search Optimization Algorithm |
| File Type: | Conference Paper |
| Issue: | Volume: S43 Inverse Finite Element Optimization in Electromagnetic Product Design and Non-Destructive Evalutation II Number: Year: 2015 |
| Download Link: | Login To Download (For Members) File Size: 251 KB |
| Title: | Wire Fault Diagnosis Based on Time-Domain Reflectometry and Backtracking Search Optimization Algorithm |
| Abstract: | The development of a robust and accurate fault diagnosis approach under various system and fault conditions is a research area of great interest. The objective of this paper is to develop a new non-destructive approach for wiring diagnosis based on Time Domain Reflectometry (TDR) in one hand and on Backtracking Search Optimization Algorithm (BSA) in the other hand. Real-world case studies are investigated to demonstrate the effectiveness and robustness of the proposed approach. Simulation results evaluated from experimental data demonstrate that the proposed approach can be used for effective diagnosis of complex wiring networks. |
| Author(s): | H. Boudjefdjouf, H. R. E. H. Bouchekara, F. de Paulis, M. K. Smail, A. Orlandi, R. Mehasni |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 4 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 723 KB |
| Title: | WIPL-D Results and Time Domain Response for an Impulse Radiating Antenna (IRA) |
| File Type: | Conference Paper |
| Issue: | Volume: Special Session: Electromagnetic Modeling by WIPL-D Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 0 KB |
| Title: | WIPL-D Results and Time Domain Response for an Impulse Radiating Antenna (IRA) |
| File Type: | Conference Paper |
| Issue: | Volume: Special Session: Electromagnetic Modeling by WIPL-D Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 193 KB |
| Title: | WIPL-D Parallelization Effort |
| File Type: | Conference Paper |
| Issue: | Volume: Special Session: Electromagnetic Modeling by WIPL-D Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 117 KB |
| Title: | WIPL-D Optimization of a Harmonic RF Tag |
| File Type: | Conference Paper |
| Issue: | Volume: EM Applications Using WIPL-D Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 340 KB |
| Title: | WIPL-D Model and Simulation Results for a 6ft Diameter Impulse Radiating Antenna (IRA) |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Electromagnetic Modeling by WIPL-D Software Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 148 KB |
| Title: | WIPL-D Compared to Other EM Codes for the Analysis of Printed Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling by WIPL-D Code Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 431 KB |
| Title: | WIPL Code Validation for Metallic Structures |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling by WIPL-D Code Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 253 KB |
| Title: | Wind Turbine RCS Modeling and Validation* |
| File Type: | Conference Paper |
| Issue: | Volume: Topics in Radar Scattering Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 201 KB |
| Title: | Wind Power Axial-Flux PM Generator Loss Computation Using Quasi-3D FEA |
| File Type: | Conference Paper |
| Issue: | Volume: S07 Low Frequency Magnetics Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 779 KB |
| Title: | Wideband, Scanning Array for Simultaneous Transmit and Receive |
| File Type: | Conference Paper |
| Issue: | Volume: S19 Broadband Antennas and Applications Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 322 KB |
| Title: | Wideband Single-Fed Circularly Polarized Stacked Patch Antenna With L-Shaped Stub |
| Abstract: | A wideband single-fed circularly polarized (CP) stacked patch antenna with an L-shaped stub is presented. The CP antenna is made up of the bottom gradient microstrip transmission line, middle driven patch and top square radiation patch. The driven patch with an Lshaped stub and opening slot can achieve a wideband CP radiation which is different from a conventional patch. The presented CP stacked patch antenna maintains good directional radiation, while featuring wideband CP radiation. The final tested results indicate that the presented CP antenna has significant performance with a –10-dB impedance bandwidth of 42.1% (4.26-6.53 GHz), a 3- dB AR bandwidth of 26.0% (4.36-5.66 GHz) and broadside peak gain of 8.6 dBic. Moreover, the fifth-generation (5G) N79 band (4.4-5.0 GHz) and 5G wireless local area network (WLAN) band (5.15-5.35 GHz) can be covered by the operating bandwidth of the presented CP antenna. |
| Author(s): | W. Li, W. Xue, Y. Li, X. Xiong, K. L. Chung, Z. Huang |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 12 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 2257 KB |
| Title: | Wideband Single Arm Spiral Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: S14 EM Modeling using FEKO - II Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 478 KB |
| Title: | Wideband Self-adjoint Jacobian Computation with Time-domain Field Solutions |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling with QuickWave/Concerto Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 210 KB |
| Title: | Wideband Quasi-Yagi Antenna with Broad-Beam Dual-Polarized Radiation for Indoor Access Points |
| Abstract: | This paper presents a wideband, broad beamwidth, dual-polarized antenna for the indoor access points. Its primary radiating elements are two quasi-Yagi antennas, which are arranged orthogonally. The antenna element employs two balanced directors to broaden bandwidth and avoid the structural conflict of the orthogonal installation. A microstrip-slotline transformer is used in the feeding structure for allowing the wideband operation and high port-to-port isolation. The dualpolarized quasi-Yagi antenna is incorporated with a metallic cavity in order to improve the unidirectional radiation in terms of gain, front-to-back ratio, and beamwidth. The final prototype has been fabricated and tested. The antenna yielded a wide impedance bandwidth covering a frequency range from 1.64 to 3.0 GHz (60%) for both ports with port-to-port isolation of a higher than 25 dB. In addition, at both ports, the antenna achieves stable unidirectional radiation with broad beamwidth, high front-to-back ratio, and high radiation efficiency. |
| Author(s): | S. X. Ta, C. D. Bui, T. K. Nguyen |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 5 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1560 KB |
| Title: | Wideband Printed Lotus Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Wideband Antennas Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 283 KB |
| Title: | Wideband Printed CPW-fed Binomial Curved Slot Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: Antenna Modeling and Small Antennas Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 250 KB |
| Title: | Wideband Printed Antipodal Vivaldi Antenna using Straight Slots for UHF DVB-T/T2 Applications |
| Abstract: | This paper presents a wideband printed antipodal Vivaldi antenna using straight slots for UHF DVB-T/T2 applications covering a frequency range of 470–862 MHz. The proposed antenna consists of two radiation flares with straight slots and a feeding line. A wideband impedance matching was achieved by inserting the slots between the flares and the feeding line. For the experimental verification of the proposed antenna, it was fabricated on a flat circular printed circuit board (PCB) substrate with a radius of 0.25 λ0, where λ0 is the wavelength at 0.74 GHz (the center frequency of the operating band). The measured −10 dB impedance bandwidth and maximum gain were approximately 72.1% (0.47–1.00 GHz) and 2.57 dBi, respectively. Due to the addition of the slots, the impedance bandwidth of the proposed antenna was improved by approximately 212% compared with the Vivaldi antenna without slots. |
| Author(s): | N.-R. Kwon, S.-H. Ahn, W.-S. Lee |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 6 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 4821 KB |
| Title: | Wideband Power Divider Using Novel Split-Ring Resonator |
| Abstract: | A set of novel split-ring resonator basic block Hybrid-Microwave Integrated-Circuit (HMIC) components (transmission line, open and short stubs) is presented with applications to the RF/Microwave power divider. This new open and short LH HMIC resonators have compact sizes of 0.81 and 1.44 mm2 , respectively. The prototypes of an LH power divider constructed from these basic components have been designed, fabricated, and characterized. The LH power divider including two LH branches shows equal power split from 1 to 7 GHz. The proposed power divider benefit from the miniaturized LH HMIC components and have compact sizes of 2.205 mm2 , respectively. There is a good agreement between the full-wave simulations and measurement results with 0.254-mm thick RT5880 substrate. While maintaining similar performance, a 50% reduction in impedance transformer is achieved in comparison to a conventional design. |
| Author(s): | T. Huang, D. Jiang, H. Hu |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 2 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 235 KB |
| Title: | Wideband Planar Slot Antennas |
| File Type: | Newsletter Paper |
| Issue: | Volume: 19 Number: 1 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 363 KB |
| Title: | Wideband Open Sleeve Dipole Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: S45 UWB and Multi-Band Antennas II Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 720 KB |
| Title: | Wideband Octagonal Dual Circularly Polarized Sub-array Antenna for Ku-Satellite Systems |
| Abstract: | In this paper the analysis and design of a dual circularly polarized 4×4 antenna array operating in Ku-band are discussed with emphasis on its sequential feeding network. The dual circular polarization is achieved by feeding a stacked octagonal patches with a wideband branch line coupler. The proposed 4×4 antenna array is based on two separate sequential feeding networks for LH and RH circular polarizations. The advantage of the proposed feeding network is that it is implemented on a single layer. Simulation results by using both HFSS and CST are presented for comparison. In addition, experimental verifications are presented. |
| Author(s): | K. M. Ibrahim, W. M. Hassan, E. A. Abdallah, A. M. Attiya |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 12 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1254 KB |
| Title: | Wideband Multi-Port Network Integrated by 3-dB Branch-Line Couplers |
| Abstract: | The design of a multi-port network integrated by symmetrical alignment of four 3-dB branch-line couplers (BLCs) for wideband communication applications is presented. The BLC is designed with the implementation of stub impedance at each port’s transmission line and defect ground structure (DGS) underneath the shunt branches of BLC to improve bandwidth. The designs of the BLC and the multi-port network are performed by using CST Microwave Studio, a three-dimensional (3D) electromagnetic wave simulator. The designed wideband BLC and multi-port are fabricated, and their wideband performances of 2.3 to 5.3 GHz are verified. |
| Author(s): | N. A. M. Shukor, N. Seman, T. A. Rahman |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 7 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2248 KB |
| Title: | Wideband Multi-polarization Reconfigurable Antenna based on Non-uniform Polarization Convert AMC Reflector |
| Abstract: | A novel design of wideband multipolarization reconfigurable antenna is proposed, based on a non-uniform polarization convert artificial magnetic conductor (AMC) reflector. The proposed antenna consists of a radiator element and an AMC reflector. Firstly, a modified polarization convert AMC reflector is designed. The non-uniform AMC reflector causes an enhancement of 3 dB axial ratio (AR) performance. Secondly, a wideband linearly polarized monopole antenna is presented as the main radiator, utilizing the broadband characteristic of a C-shaped monopole. The polarization reconfigurability of the proposed antenna can be achieved by properly rotating the AMC reflector, which can be switched between linear polarization (LP), lefthand circular polarization (LHCP), and right-hand circular polarization (RHCP). A prototype of the proposed antenna is fabricated and experimented with to validate the theoretical performance. The measured results show a - 10 dB impedance bandwidth of 42.7% and 44.4% for LP and CP modes, respectively, and a 3 dB AR bandwidth of 20% for CP modes. In addition, the measured peak gain reaches 8 dBi/dBic. A good agreement is shown between the simulation and measurement, pointing to the good performance of the proposed antenna. |
| Author(s): | L. Li, J.-J. Liang, X. Liu, T. Chen, J. Lv, Z. Wu |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 9 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 6353 KB |
| Title: | Wideband Monostatic RCS Prediction of Complex Objects using Support Vector Regression and Grey-wolf Optimizer |
| Abstract: | This paper presents a method based on the support vector regression (SVR) model and grey wolf optimizer (GWO) algorithm to efficiently predict the monostatic radar cross-section (mono-RCS) of complex objects over a wide angular range and frequency band. Using only a small-size of the mono-RCS data as the training set to construct the SVR model, the proposed method can predict accurate mono-RCS of complex objects under arbitrary incident angle over the entire three-dimensional space. In addition, the wideband prediction capability of the method is significantly enhanced by incorporating the meta-heuristic algorithm GWO. Numerical experiments verify the efficiency and accuracy of the proposed SVR-GWO model over a wide frequency band. |
| Author(s): | Z. Zhang, P. Wang, M. He |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 8 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 13038 KB |
| Title: | Wideband MIMO Directional Antenna Array with a Simple Meta-material Decoupling Structure for X-Band Applications |
| Abstract: | In this paper, a compact wideband MIMO directional antenna array with a single-layered meta-material is proposed to realize high isolation. The meta-material decoupling structure, which is composed of a modified split-rings and a square loop structure, is suspended over the two antenna elements to reduce the mutual coupling. The achieved results show that the proposed antenna array owns a −10 dB impedance bandwidth ranging from 8.5 GHz to 11.5 GHz. Furthermore, by loading the proposed meta-material superstrate over the two-element MIMO antenna, the designed MIMO antenna array not only has good performance but also enhances the isolation to be more -15 dB within the operating frequency band. In addition, the performances of the proposed antenna array are also tested by radiation pattern, gain, envelope correlation coefficient, diversity gain, total active reflection coefficient and so on. Therefore, these simulation results prove that the proposed wideband MIMO directional antenna array is a suitable candidate for X-band communication. |
| Author(s): | J. Jiang, Y. Li, L. Zhao, X. Liu |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 5 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 21801 KB |
| Title: | Wideband Microstrip Patch Antennas with Transverse Electric Modes |
| Abstract: | A wideband microstrip patch antenna, exciting the fundamental transverse electric (TE) mode, is investigated. The excitation of the TE mode is facilitated through replacing both of the patch and ground plane of a conventional microstrip antenna with artificial magnetic conductors (AMC), consisting of unipolar compact photonic bandgap (UC-PBG) unit cells. The AMC patch and the ground plane of this antenna behave as magnetic conductors within the bandgap region of the unit cells. Similar to conventional patch antennas, it is shown that by cutting a U-shaped slot in the AMC patch, wideband characteristics are realized. The antenna shows a 40% impedance bandwidth and operates at the TE10 mode. Moreover, the width of the patch is 1.75 times smaller than its length, reducing the overall size of the antenna by about 60%, compared with the conventional U-slot PEC antenna supporting the transverse magnetic (TM) mode. |
| Author(s): | T. Mitha, M. Pour |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 8 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1356 KB |
| Title: | Wideband Microstrip Patch Antennas with Transverse Electric Modes |
| Abstract: | A wideband microstrip patch antenna, exciting the fundamental transverse electric (TE) mode, is investigated. The excitation of the TE mode is facilitated through replacing both of the patch and ground plane of a conventional microstrip antenna with artificial magnetic conductors (AMC), consisting of unipolar compact photonic bandgap (UC-PBG) unit cells. The AMC patch and the ground plane of this antenna behave as magnetic conductors within the bandgap region of the unit cells. Similar to conventional patch antennas, it is shown that by cutting a U-shaped slot in the AMC patch, wideband characteristics are realized. The antenna shows a 40% impedance bandwidth and operates at the TE10 mode. Moreover, the width of the patch is 1.75 times smaller than its length, reducing the overall size of the antenna by about 60%, compared with the conventional U-slot PEC antenna supporting the transverse magnetic (TM) mode. |
| Author(s): | T. Mitha, M. Pour |
| File Type: | Express Journal Paper |
| Issue: | Volume: 35 Number: 8 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 410 KB |
| Title: | Wideband Microstrip Patch Antenna at 7 GHz |
| File Type: | Conference Paper |
| Issue: | Volume: Student Microwave Design Projects with Sonnet Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 211 KB |
| Title: | Wideband Microstrip Endfire Antenna based on SIW and Magnetic Dipole |
| File Type: | Conference Paper |
| Issue: | Volume: 1-P1-C Wideband and Multiband Antennas Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 420 KB |
| Title: | Wideband LTCC Vertical-Fed Dipole Antenna for Millimeter-Wave Applications |
| File Type: | Conference Paper |
| Issue: | Volume: 2-2-B Millimeter Wave and Terahertz Antennas Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 529 KB |
| Title: | Wideband Low Profile Multi-Polarization Reconfigurable Antenna with Quasi-cross-shaped Coupling Slot |
| Abstract: | A wideband low profile multi-polarization reconfigurable antenna with quasi-cross-shaped coupling slot is proposed. The antenna consists of an upper oval radiating patch, the quasi-cross-shaped coupling slot, fork-shaped folded feed lines and a reconfigurable Wilkinson power divider network with four pairs of p-in diodes. The antenna reconfigurable polarization modes change among ±45° Linear polarization (LP), dual-LP, left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) by controlling the ON/OFF states of the p-i-n diodes. The designed prototype has been fabricated and measured. Good agreement between the measured and simulated results is achieved. Measured results show that the antenna has wide impedance bandwidth (over 21.35% for LP and 17.70% for CP) and axial ratio (AR) bandwidth (16.13% for LHCP and 16.88% for RHCP). The average realized gains are about 7.6 dBi for different polarization modes. The proposed antenna has the advantages of multi-polarization reconfigurable ability, wide bandwidth, low profile, and high gains, which make it possible to be applied to wireless communication systems. |
| Author(s): | Q. Xu, Z. Liu, S. Liu, X. Kong, Z. Huang, B. Bian, Q. Yu, J. Qin |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 3 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1903 KB |
| Title: | Wideband Iris-Fed Patch Antenna Under Operation of Dual-Resonance for X-band Applications: MOM-GEC Approach |
| Abstract: | In this paper, a microstrip patch antenna fed by a waveguide using an end-wall iris through ground plane has been modelled. The iris feed technique was proposed to overcome the narrow bandwidth problem of microstrip patch antenna. The iris is sized so that it is resonant and subsequently the antenna operates under the fusion of two modes relating to the iris and the patch, resulting in a wideband radiation characteristic with dual resonance. Measurement demonstrates the single bandwidth dual resonance type and the radiation bandwidth of (8 GHz-10.6 GHz). In order to show the impact of the iris feed technique on microstrip patch antenna’s bandwidth, a comparison with some state-of-the-art works proposing various bandwidth enhancement techniques in the X-band is made. The proposed prototype, with a size of 1.76λ0×1.65λ0×1.29λ0, is more compact than several designs. It has a fractional bandwidth of 27.9%, thus it presents the prototype with the widest bandwidth with the simplest design fabrication. With regard to the electromagnetic modelling, this work is oriented towards the use of the hybrid MOM-GEC method in order to be able to perform a rigorous electromagnetic. It has been found that the MOM-GEC model is more efficient in terms of memory requirements and approximately four times faster than HFSS simulator software. |
| Author(s): | M. Abdi, T. Aguili |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 2 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 4305 KB |
| Title: | Wideband High-Gain Fabry-Perot Resonator Antenna with Small Footprint Dielectric Superstrates and a Conical Short Horn |
| File Type: | Conference Paper |
| Issue: | Volume: 2-1-B Modeling, Optimization and Design of Antennas Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 421 KB |
| Title: | Wideband Hexagonal Fractal Antenna on Epoxy Reinforced Woven Glass Material |
| Abstract: | In this paper a novel hexagonal-circular Fractal antenna is proposed for wideband applications. The proposed antenna is made of iterations of a circular slot inside a hexagonal metallic patch with a transmission line and is fabricated on low cost epoxy matrix reinforced woven glass material. Measurement shows that with a dimension of 0.36?0×0.36?0×0.0071?0 (where ?0 is the lower edge frequency of the operating band), the proposed antenna achieves a wide impedance bandwidth ranging from 1.34 GHz to 3.44 GHz (88%). The proposed antenna also achieves high gain and exhibits a stable radiation pattern which makes it suitable for many wireless communications such as DCS-1800, PCS-1900, IMT-2000/UMTS, ISM (including WLAN), Wi-Fi and Bluetooth. |
| Author(s): | M. A. Dorostkar, R. Azim, M. T. Islam, Z. H. Firouzeh |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 902 KB |
| Title: | Wideband GCPW-Fed Dielectric Resonator Antenna for WLAN Applications |
| File Type: | Conference Paper |
| Issue: | Volume: S19 Broadband Antennas and Applications Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 412 KB |
| Title: | Wideband Filtering Crossover Based on Ring Resonator with Sharp Rejection |
| Abstract: | A wideband filtering crossover based on ring resonators with sharp rejection is proposed in this paper. Four transmission zeros near the crossover passband can be adjusted conveniently by the even/odd-mode characteristic impedance of the coupled lines. A high selectivity wideband filtering crossover located at 3.0 GHz is designed and fabricated for verification. Good filtering performance and high selectivity for the crossover are realized and experimentally verified. |
| Author(s): | W. Yang, W. Feng, W. Che |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 10 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 2101 KB |
| Title: | Wideband Fabry-Perot Cavity Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: 2-1-B Modeling, Optimization and Design of Antennas Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 350 KB |
| Title: | Wideband Equivalent Circuit Model and Parameter Computation of Automotive Ignition Coil Based on Finite Element Analysis |
| Abstract: | This paper presents a coupled fieldcircuit method to predict the wideband characteristic of ignition coils. A lumped circuit model is proposed, which separates the winding of ignition coil into individual sections. In this circuit model, the capacitance between sections, turn-toturn series capacitance of each single section and inductance of winding are calculated by Finite Element Analysis (FEA). This parameter identification is based on the energy principle. In addition, this paper analyzes the influence of frequency on the magnetic-flux distribution and the inductance, using the finite-element model with T- ? formulation. The parameter inductance applied to the circuit model is classified into high frequency inductance and low frequency inductance. Through contrasting the measured and calculated result in frequency and time domain, reliability and feasibility of the presented method in this paper is verified. |
| Author(s): | J. Jin, W. Quan-di, Y. Ji-hui, Z. Ya-li |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 7 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 1059 KB |
| Title: | Wideband Dual-polarized Vivaldi Antenna with Gain Enhancement |
| Abstract: | A wideband dual-polarized Vivaldi antenna covering 1.85-18.3 GHz band with enhanced gain is presented in this letter. The proposed antenna consists of two Vivaldi antenna elements (VAEs), which are designed based on the conventional Vivaldi antenna. Dual-slot structure is employed to improve the gain of the conventional Vivaldi antenna. As a result, sphericallike waves across the slot aperture of the conventional Vivaldi antenna can be transformed to be plane-like waves and thus gain enhancement can be achieved. In order to extend lower frequency limit of the VAE, elliptical slots are adopted. The proposed dual-polarized Vivaldi antenna is obtained by combining two VAEs in a cross-shaped form. The prototype is simulated, fabricated, and measured. A good agreement between EM simulated and measured results evidently validates the proposed antenna. |
| Author(s): | H. Lv, Q. Huang, J. Hou, J. Liu |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 9 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2769 KB |
| Title: | Wideband Dielectric Resonator Antenna with Parasitic Strip |
| File Type: | Conference Paper |
| Issue: | Volume: Dielectric Resonator Antennas Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 270 KB |
| Title: | Wideband Dielectric Resonator Antenna Excited by a Closed Circular Loop GCPW Slot for WLAN 5.5 GHz Applications |
| Abstract: | A dielectric resonator antenna is designed for WLAN 5.5 GHz band applications in this study. The dielectric resonator antenna is fabricated on a cheap FR4 substrate with grounded CPW (GCPW) structure. A new closed circular loop GCPW slot structure is employed to obtain wideband impedance matching. Results of the designed dielectric resonator antenna show that good agreement between simulated and measured reflection coefficients, radiations, and antenna gains is observed. The measured -10 dB bandwidth of the dielectric resonator antenna is 1.6 GHz (28.5%, 4.8 – 6.4 GHz), which covers the WLAN 5.5 GHz band. |
| Author(s): | W.-C. Weng, M.-C. Chang, M.-S. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 2 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1811 KB |
| Title: | Wideband Decoupled 8-Element MIMO Mobile Phone Antenna for Sub-6GHz 5G NR Bands |
| Abstract: | A broadband decoupled dual antenna pair suitable for sub-6G mobile terminal application is proposed and designed. The multiple input multiple output (MIMO) antenna pair is arranged on the metal frame of the mobile phone, with two antenna pairs on each metal frame. The slotted antenna element structure and defect ground decoupling structure are used to achieve wide band and high isolation. Based on the decoupled antenna pair, an eight-element MIMO antenna is designed. Similarly, the coupling between antenna pairs is effectively reduced by etching the decoupled defect structure of a zigzag shape on the system surface. The prototype of the antenna array is successfully fabricated and tested. Simulation and experimental results show that the proposed eight-element MIMO antenna can fully cover the n77/n78/n79 band of 5G New Radio and 5 GHz band of WLAN. The overall efficiency of the antenna is 50%- 75%, the envelope correlation coefficient (ECC) is below 0.08, and the isolation between any two ports is better than 11 dB. |
| Author(s): | J. He, S. Zhu, J. Yu, H. Li, G. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 12 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 1119 KB |
| Title: | Wideband Compact Antenna with Partially Radiating Coplanar Ground Plane |
| Abstract: | Many of today's portable communication applications require antennas that are compact, broadband, and easily integrable in a big variety of terminal geometries. This paper presents a compact wideband antenna with partially radiating coplanar ground plane. The prototype of the antenna shows a wide bandwidth (VSWR ? 2) of 92% (from 3.53GHz to 9.5GHz). The antenna also exhibits maximum gain of 3.5dBi and stable radiation patterns over the whole bandwidth. Nevertheless, in this paper the significance of the ground planes on the operating bandwidth are examined with the help of current distribution and discussed in detail with supporting parametric analysis. |
| Author(s): | A. T. Mobashsher, M. T. Islam, N. Misran |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 608 KB |
| Title: | Wideband Center-fed Stacked Patch Circularly Polarized Antenna used in Phased Array |
| Abstract: | A center-fed circularly polarized stacked patch antenna (CF-CPSPA) with enhanced axial-ratio (AR) bandwidth is proposed in this paper. The antenna is composed of two microstrip patches, the lower patch consists of a circular pad, an elliptical-ring, and two branch lines connecting them, which is used to realize the center-fed condition, and the upper patch is an elliptical patch to achieve the wide band performance. Firstly, two center-fed linearly polarized stacked patch antennas with wide band are designed, one mode radiated with x polarization, and the other generates y polarized radiation. Next, the orthogonal modes of two linearly polarized antennas are combined together by a specific design. Finally, the approximate equal amplitude and quadrature phase difference of the introduced modes are achieved in the operating frequency band with proper parameters analysis. And the impedance bandwidth and 3dB AR bandwidth is improved to 30.4% and 16.5%. |
| Author(s): | J. Wang, X. Liu, P. Zhang, Z. Xu, A. Li, Z. Chen, J. Fan |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 10 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 4563 KB |
| Title: | Wideband Bow-Tie Slot Antennas with Tapered Tuning Stubs |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Computational Techniques for Antenna Design Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 113 KB |
| Title: | Wideband and High Gain Shared-Aperture Fabry-Perot Resonator Microstrip Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: 2-P2-E Antennas with Advanced/Artificial Materials and Processes Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 386 KB |
| Title: | Wideband and Dual-Band Loaded Monopole Dielectric Resonator Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Antenna Applications Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 195 KB |
| Title: | Wide-Angle Claerbout Scheme for Three-Dimensional Time Domain Parabolic Equation and its CN, ADI, AGE Solutions |
| Abstract: | The wide-angle Claerbout scheme of three-dimensional time domain parabolic equation (Claerbout-TDPE) is derived in this paper, which can provide accurate results at angles within 25° of the paraxial direction. At first, the Crank-Nicolson (CN) type is introduced to discretize the Claerbout-TDPE. In this way, a three-dimensional EM scattering problem can be divided into a series of two-dimensional ones. Moreover, the alternating direction implicit (ADI) type is utilized to the Claerbout-TDPE. In this way, a three-dimensional EM scattering problem can be further reduced to a series of one-dimensional ones. Furthermore, the alternating group explicit (AGE) type is introduced to the Claerbout- TDPE for higher computational efficiency. Comparisons are made among the CN, ADI and AGE types in the numerical results. |
| Author(s): | Z. He, H.-C. Yin, R.-S. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 3 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1847 KB |
| Title: | Wide-Angle Absorbing Boundary Conditions for Low and High-Order FDTD Algorithms |
| Abstract: | Wide-angle performance of the perfectlymatched- layer absorbing boundary conditions for the finite-difference time-domain (FDTD) method is investigated for efficient modeling of electrically large structures. The original split-field, uniaxial and convolutional perfectly-matched-layer formulations are all optimized to produce near-flat absorption for incidence angles up to 87 degrees. Optimized wide-angle parameters are derived for both the standard FDTD method and a high-order finite-volumes-based variant. The investigated high-order algorithm in particular is shown to produce improved wide-angle performance over standard FDTD for all three perfectly-matched-layer variants even when they are optimized for normal wave incidence. In all cases, optimization is managed through appropriate choices of modeling parameters which can be directly and unobtrusively applied to existing FDTD codes. |
| Author(s): | Mohammed F. Hadi |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 1 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 113 KB |
| Title: | Wide Stop-Band Microstrip Lowpass Filter with Sharp Roll-off Using Hairpin Resonators |
| Abstract: | A compact microstrip lowpass filter with wide stop-band and sharp roll-off skirt is presented. The structure consists of a combination of modified Hairpin units. The cut-off frequency is 3.1 GHz. The proposed low-pass filter has a very good performance such as extended stop-band bandwidth from 3.36 GHz to 21.5 GHz with the insertion-loss higher than -20.0 dB, sharp roll-off, low insertion-loss, and high return-loss in the passband. The filter is designed, fabricated, and tested and the measured results are in good agreement with the EM-simulation results. |
| Author(s): | M. Hayati, H. S. Vaziri |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 10 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 1113 KB |
| Title: | Wide Bandwidth Endfire Antenna with Log-Period Directors |
| Abstract: | This paper presents the design and implementation of a novel wide bandwidth endfire antenna with log-periodic directors. The feeding structure of the proposed antenna includes a balun which is formed using a pair of microstrip-to-slotline transitions. The proposed antenna has three resonant frequencies in the operating frequency band. Both simulation and measurement results show that the operating frequency band of the antenna for S11 < -10 dB covers the wide bandwidth (5 GHz – 10 GHz), and the relative bandwidth is 67%. Far field measurements in azimuth plane and elevation plane show that the radiation patterns are stable and end fire within the operating band at frequencies of 5 GHz, 7 GHz, 8 GHz, 10 GHz. The proposed antenna radiates a well-defined endfire beam, with a front-to-back ratio > 18 dB and cross polarization level below -28 dB. The dimension of the proposed antenna is 26 mm × 27 mm. Good return loss and radiation pattern characteristics are obtained and measured results are presented to validate the usefulness of the proposed antenna structure for wide bandwidth endfire applications. |
| Author(s): | Y. Sun, G. Wen, H. Jin, P. Wang, Y. Huang, J. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 11 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 957 KB |
| Title: | Wide Band Wide Scanning Angle Phased Array Antenna Design in Ku-band |
| File Type: | Conference Paper |
| Issue: | Volume: 1-P1-C Wideband and Multiband Antennas Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 242 KB |
| Title: | Wide Band Implantable Antenna Operating at MedRadio Band for MBAN Devices |
| File Type: | Conference Paper |
| Issue: | Volume: 1-4-D EM, Antennas and Wireless Power for Biomedical Applications Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 295 KB |
| Title: | Wide Band Flexible Terahertz Metasurface Wave Plate |
| File Type: | Conference Paper |
| Issue: | Volume: 1-SP-4 Metasurfaces/Metamaterials Theory, Design and Applications I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 388 KB |
| Title: | Wide Band Antenna with Ultra-smooth Spectral Characteristics |
| File Type: | Conference Paper |
| Issue: | Volume: S09 Advances in Electromagnetic Modeling by WIPL-D - I Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 389 KB |
| Title: | Wide Band Antenna with Ultra-smooth Spectral Characteristics |
| Abstract: | Understanding the evolution of Universe is, in the forefront of, the modern day observational cosmology. It requires precise and accurate measurement of cosmological signal, orders of magnitude weaker than the bright sky background. Detection of such a signal having distinct spectral signature, needs an antenna with frequency independent characteristics over more than an octave bandwidth. A spherical monopole antenna has been designed to operate in the frequency range 50-200 MHz with a spectral smoothness of about few parts in 104. The structure has been modeled and optimized using WIPL-D, to minimize spectral features arising out of abrupt reflections of surface currents and frequency dependent radiation patterns. A prototype has been built to validate the design. This paper presents the methodology adopted in the overall antenna design, experiences in its prototyping and simulation and the measurement results. |
| Author(s): | A. Raghunathan, B. S. Girish, R. Somashekar, K. S. Srivani, S. Singh, R. Subrahmanyan, N. U. Shankar, M. S. Rao, J. Nambissan T. |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1331 KB |
| Title: | Why does SBVH outperform KD-tree on parallel platforms? |
| File Type: | Conference Paper |
| Issue: | Volume: S41 Parallel and GPU Computations Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 191 KB |
| Title: | Whistler Mode Wave Refractive Index in a Finite Temperature Anisotropic Plasma Medium |
| Abstract: | Whistler mode waves, which exist in a magnetized plasma, are prevalent in the Earth's magnetosphere in the extremely low frequency (ELF) and very low frequency (VLF) bands (100 Hz - 30 kHz). Due to the impact of whistler mode waves on space weather processes, it is important to accurately predict the propagation trajectory of these waves and their properties. Numerical raytracing determines the power flow path of the whistler mode waves in the anisotropic medium of the magnetosphere based on local calculation of the refractive index. In the majority of previous work, magnetospheric raytracing has been implemented assuming a cold background plasma (0 K). However, a more accurate description of the magnetospheric plasma includes a background temperature of about 1 eV (11600 K). We present solutions to the dispersion relation that include the effects of finite electron and ion temperatures on the wave refractive index using a warm plasma formulation. Finite temperature effects of the background plasma are shown to be most significant for highly oblique wave normal angles where the refractive index is bounded to smaller values than in the ideal cold plasma approximation. |
| Author(s): | M. Golkowski, A. Maxworth |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 10 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1848 KB |
| Title: | Whistler Mode Wave Numerical Raytracing in a Finite Temperature Anisotropic Plasma Medium |
| File Type: | Conference Paper |
| Issue: | Volume: S39 Modeling Electromagnetic Waves in Plasma Environments Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 273 KB |
| Title: | Whispering Gallery Mode Laser in an Elliptical Microring |
| Abstract: | Studies on whispering gallery mode (WGM) laser in microrings have been limited to circular geometry. Elliptical microring lasers, despite their potential engineering use, have not been analyzed to guide experiments. This paper introduces a computationally efficient method for determining the WGM laser resonance and the laser field distribution in an elliptical microring. An analytical method is applied to avoid computing high order Mathieu functions. Both WGM resonant frequencies and electromagnetic (EM) field distributions are computed and presented in this paper. Computed results clearly show that the WGM laser field is concentrated on the outer surface of the microring. Results also show that the eccentricity of the ellipse affects the distribution of resonant frequencies and the laser field. |
| Author(s): | R. Baktur, L. W. Pearson, J. M. Ballato |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 2 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 419 KB |
| Title: | Where Intangibles Collide |
| File Type: | Newsletter Paper |
| Issue: | Volume: 20 Number: 2 Year: 2005 |
| Download Link: | Click here to download PDF File Size: 214 KB |
| Title: | Where does the radiation come from? |
| File Type: | Conference Paper |
| Issue: | Volume: Poster Session 1 Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 89 KB |
| Title: | What Do You Mean By a Solution to an Operator Equation? |
| Abstract: | The main thrust of this presentation is to illustrate that for many electromagnetic field problems the quality of the solution is very subjective and not objective at all. Therefore to classify solutions on a subjective criteria which is not scientific will create more problems than it would solve. The underlying feature to all this is what do "we mean" by a solution. |
| Author(s): | T.K. Sarkar, E. Arvas, T.K. Sarkar, E. Arvas |
| File Type: | Journal Paper |
| Issue: | Volume: 4 Number: 3 Year: 1989 |
| Download Link: | Click here to download PDF File Size: 333 KB |
| Title: | Well-Conditioned CFIE for Scattering from Dielectric Coated Conducting Bodies above a Half-Space |
| Abstract: | In this paper, a well-conditioned coupled combined-field integral equation called the electric and magnetic current combined-field integral equation (JCFIE-JMCFIE) is proposed for the analysis of electromagnetic scattering from coated targets above a lossy half-space. The halfspace multilevel fast multipole algorithm (MLFMA) is used to reduce computational complexity. The inner-outer flexible generalized minimal residual method (FGMRES) was used as the iterative solver to further speed up the convergence rate. Numerical results were presented to demonstrate the accuracy and efficiency of the proposed method. |
| Author(s): | D. Ding, J. Ge, R. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 11 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 401 KB |
| Title: | Well-Conditioned 2D Models of Rod Arrays for Accelerating 3D Simulations of Photonic Crystals and Plasmonic Structures |
| File Type: | Conference Paper |
| Issue: | Volume: S06 Advanced Methods for Numerical Electromagnetic Analysis - I Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 1009 KB |
| Title: | Wearable Textile Fabric Based 3D Metamaterials Absorber in X-Band |
| Abstract: | In this paper, a new wearable (flexible) textile fabric-based 3D metamaterials absorber (MMA) structure is proposed. The proposed MMA was created from three layers; weft-knitted fabric, silicone, and plain weave fabric and then, it was simulated in Computer Simulation Technology (CST). It was obtained maximum absorption power (99.66%) at 9.38 GHz, and the average absorption power of 81-95% was obtained in the frequency range of 8 to 12 GHz depending on the incident angle in the simulation. The effect of the wearable textile structure on absorption was investigated. When compared with other materials, it can be said that the proposed MMA is broadband, incident angle independent, TE and TM polarization-independent, flexible, breathable, wearable, ease of fabrication, practical, low weight, and cost advantage. With this designed the textile fabric-based MMA, it can be obtained both low reflection coefficients and low transmission coefficients at broadband X-band frequencies. This provides a good solution for the cloaking of radar systems. |
| Author(s): | E. Delihasanlar, A. H. Yuzer |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 2 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1722 KB |
| Title: | Wearable Radar Antenna Array Design on Flexible PCB for Visually Impaired People |
| File Type: | Conference Paper |
| Issue: | Volume: S47 Advanced Antenna Designs for Emerging Wireless Applications Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 304 KB |
| Title: | Wearable Panda-Shaped Textile Antenna with Annular Ring-Defected Ground Structure for Wireless Body Area Networks |
| Abstract: | This research presents a compact pandashaped wearable antenna with a defected ground structure (DGS). It is fabricated using a flexible material to work at 2.4-GHz industrial scientific medical (ISM) band, confirming the wireless body area network (WBAN) application requirements. The annular ring DGS and circular and elliptical slots in the patch aid in achieving the operating frequency. Good impedance bandwidth is maintained during on-body and bending analysis. Furthermore, this antenna exhibits a peak gain of 7.3 dB and a minimum specific absorption rate (SAR) of 0.0233 W/kg for 1 g tissue and 1.02 W/kg for 10 g tissue. The investigation shows that an antenna with good robustness, compact, high flexibility, and very low SAR makes it a strong candidate for WBAN applications. |
| Author(s): | T. Annalakshmi, S. Ramesh |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 5 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 3568 KB |
| Title: | Wearable Graphene Based Curved Patch Antenna for Medical Telemetry Applications |
| Abstract: | In order to explore the expediency of graphene for biotelemetry in Wireless Body Area Network (WBAN), conformal square patch antenna design has been presented in this paper. The operational efficiency of the antenna is attributed to the incredible properties of graphene as patch conductor. The proposed antenna designed for operating in band from 1-4.88 GHz is fed with microstrip line and quarter wave transformer for impedance matching. The antenna however achieves best performance at 2.4 GHz in ISM band with good impedance matching, reasonable dB gain and high radiation efficiency for the wideband of frequencies in GHz range. The proposed wearable conformal graphene based antenna is optimally positioned at distance from body to make it suitable for Ultra Wide Band (UWB) health monitoring systems fulfilling the requirements of wideband operation, high gain and improved radiation efficiency at reduced SAR. |
| Author(s): | R. Bala, R. Singh, A. Marwaha, S. Marwaha |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 5 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 798 KB |
| Title: | Wearable Antennas for Body-Centric Communications: Design and Characterization Aspects |
| Abstract: | Wearable antennas exhibit numerous challenges in terms of design and optimization due to the specific environment in which they operate. Therefore, the design of such antennas is a non-trivial task, as multiple constraints have to be satisfied. We present an algorithm for design-and-optimization of flexible wearable antennas with high radiation efficiency and low specific absorption rate, that takes into account the dielectric loading of the human body. It provides a list of feasible antenna designs, not just a single solution, and identifies the optimal wearable antenna design. Numerical examples on the design and optimization of a wearable antenna (based on a dipole structure with a reflector) to demonstrate the validity and efficiency of the proposed algorithm are given. The optimal antenna design shows robust on-body performance and provides a suitable balance between small antenna size (antenna surface is 2214 mm2), high radiation efficiency (57.73%), and low value of the maximum 10 g average SAR (0.112 W/kg) on a homogeneous semisolid phantom. Finally, the optimal antenna design is fabricated. The antenna performance is studied under different conditions: on a homogeneous semisolid phantom, on a liquid phantom, on a three-layer semisolid phantom, on a human arm and in the free space. A good agreement between simulated and measured antenna performance is observed. |
| Author(s): | A. G. Al-Sehemi, A. A. Al-Ghamdi, N. T. Dishovsky, N. T. Atanasov, G. L. Atanasova |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 8 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1835 KB |
| Title: | Wearable and implantable RFIDs for Human-body Sensing |
| File Type: | Conference Paper |
| Issue: | Volume: RFIday 2010 Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 149 KB |
| Title: | Ways to Improve Computational Efficiency of GRE |
| File Type: | Conference Paper |
| Issue: | Volume: High Frequency Techniques Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 437 KB |
| Title: | Waveport Modeling for DGTD Method and Its Applications |
| File Type: | Conference Paper |
| Issue: | Volume: 2-SE-3 Advances in Electromagnetic Theory and Simulation Techniques II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 7 KB |
| Title: | Wavelet Packet Transform with Iterative Technique based on Method of Moments |
| File Type: | Conference Paper |
| Issue: | Volume: MoM and Applications Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 211 KB |
| Title: | Wavelet Packet Transform of the Method of Moments Matrix for Large-Scale Problems |
| File Type: | Conference Paper |
| Issue: | Volume: MoM and Applications Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 191 KB |
| Title: | Wavelet Model of Multivariate Prior Covariance |
| File Type: | Conference Paper |
| Issue: | Volume: S59 Uncertainty Quantification and Modeling for Complex Applications Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 397 KB |
| Title: | Wavelet Analysis of Permanent Magnet Synchronous Machine Flux Density Harmonic Content With Different Pole Number Designs |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in CEM Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 372 KB |
| Title: | Waveguides with Hyperbolic Metasurface Claddings |
| File Type: | Conference Paper |
| Issue: | Volume: Student Paper Competition Number: Year: 2014 |
| Download Link: | Login To Download (For Members) File Size: 588 KB |
| Title: | Waveguides with Hyperbolic Metasurface Claddings |
| File Type: | Conference Paper |
| Issue: | Volume: Computational Methods in Nanoelectromagnetics Number: Year: 2014 |
| Download Link: | Login To Download (For Members) File Size: 588 KB |
| Title: | Waveguides with Exceptional Points of Degeneracy of Order 2, 3, 4 and 6 without Loss and Gain |
| File Type: | Conference Paper |
| Issue: | Volume: S33 Complex Meta-Structures and Applications - II Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 1967 KB |
| Title: | Waveguide Mode Computation through Smoothed Particle Electromagnetics |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling, Design and Optimization of Complex Electromagnetic Systems Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 160 KB |
| Title: | Waveguide Microwave Imaging: Solids Volume Fraction of Particulate Materials |
| Abstract: | An original modeling-based microwave imaging technique for determining the volume fraction of solid material in dielectric powders is described. The desired characteristic is determined by analyzing S-parameter measurements in a waveguide containing the sample with the help of an artificial neural network trained by data from 3D FDTD simulation. The powder sample is represented by a mixture of air and millimeter-scale particles reproduced in the FDTD model. Computational tests with 20 to 40 mm cubic samples of SiC and ZrO2 powders in WR340 show that the solids volume fraction is determined with less than 5% error. |
| Author(s): | A. V. Brovko, E. K. Murphy, V. V. Yakovlev |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 11 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 2551 KB |
| Title: | Waveguide Filter Modeling and Simulation using Mode-matching, Fullwave Network Analysis and Swarm Optimization |
| Abstract: | This paper presents the modeling of waveguide bandpass filter synthesis. It consists of a combination of the most appropriate and reliable methods and techniques of analysis, simulation and optimization used in determined order and leading to a fast and accurate method of filter synthesis. An example of a forth-order filter synthesis is given, employing a symmetric configuration and symmetric response. The obtained results, reference measurement and commercial software simulator results are compared for validation. |
| Author(s): | I. Bouchachi, J. Mateu, M. L. Riabi |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 2 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1964 KB |
| Title: | Wavefront Reconstruction Using a Dispersive Propagation Model |
| File Type: | Conference Paper |
| Issue: | Volume: Inverse Scattering in Medicine and Biology - State of the Art, Recent Advances and Future Trends Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 146 KB |
| Title: | Waveform of Class E Power Amplifiers with PI Network |
| File Type: | Conference Paper |
| Issue: | Volume: 4-1-C Passive/Active Microwave and Terahertz Devices Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 242 KB |
| Title: | Wave Propagation on Two Dimensional Doubly-Periodic Guiding Structures. |
| File Type: | Conference Paper |
| Issue: | Volume: Computer Simulation of Electromagnetic-System Testing Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 168 KB |
| Title: | Wave Propagation on a Circular Chiral Rod |
| File Type: | Conference Paper |
| Issue: | Volume: Guided Waves in Non-Standard Media Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 84 KB |
| Title: | Wave Propagation and Radio Network Planning Software WinProp added to the Electromagnetic Solver Package FEKO |
| File Type: | Conference Paper |
| Issue: | Volume: S19 Modeling with FEKO Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 972 KB |
| Title: | Wave Propagation Along a Thin Vertical Wire Antenna Placed in a Horizontally Layered Medium |
| File Type: | Conference Paper |
| Issue: | Volume: Fundamental Electromagnetics: Materials and Boundaries Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 261 KB |
| Title: | Wave Concept Iterative Process Merges with Modal Fast Fourier Transformation to Analyze Microstrip Filters. |
| Abstract: | A novel iterative method based on the concept of waves is reported for use in the field theory, computer aided design and optimization of high frequency integrated circuits. It consists of a recursive relationship between a given source and reflected waves from the discontinuity plane which is divided into cells. A high computational speed has been achieved by using Modal Fast Fourier Transformation (MFFT). The theory as well as its procedure implementation is described. Numerical results are succussfully compared with published data. |
| Author(s): | A. Gharsallah, R. Garcia, A. Gharbi, H. Baudrand, A. Gharsallah, R. Garcia, A. Gharbi, H. Baudrand |
| File Type: | Journal Paper |
| Issue: | Volume: 16 Number: 1 Year: 2001 |
| Download Link: | Click here to download PDF File Size: 459 KB |
| Title: | Wave Concept in MoM-GEC Formalism |
| File Type: | Conference Paper |
| Issue: | Volume: S34 Computational Electromagnetics Advanced Algorithms and Emerging Applications IV Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 173 KB |
| Title: | Wave Characteristics Of Layered Anisotropic Media for Remote Sensing Applications |
| File Type: | Conference Paper |
| Issue: | Volume: S49 EM Modeling and Applications - II Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 169 KB |
| Title: | Water-based Metamaterial Absorber for Broadband Electromagnetic Wave Absorption |
| File Type: | Conference Paper |
| Issue: | Volume: 2-1-C Properties, Modelling and Novel Concepts of Artificial Electromagnetic Structures I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 521 KB |
| Title: | Water Extraction of SAR Image Based on Region Merging Algorithm |
| File Type: | Conference Paper |
| Issue: | Volume: 2-1-E Synthetic Aperture Radar Techniques and Applications I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 314 KB |
| Title: | Water Content and Tissue Composition Effects on Microwave Tomography Results |
| File Type: | Conference Paper |
| Issue: | Volume: Microwave Imaging and Inverse Problems Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 310 KB |
| Title: | Waffle Iron Filter Design using WIPL-D |
| File Type: | Conference Paper |
| Issue: | Volume: S20 Advances in Electromagnetic Modeling by WIPL-D - II Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 914 KB |
| Title: | W-Band Longitudinal-Slot Coupling Four-Way SIW Power Combiner/Divider |
| File Type: | Conference Paper |
| Issue: | Volume: 3-P3-H Passive/Active Microwave and Terahertz Devices Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 352 KB |
| Title: | W-band High-Gain Antenna Arrays with Low-Loss Gap Waveguide Feeding Network |
| File Type: | Conference Paper |
| Issue: | Volume: 2-1-B Modeling, Optimization and Design of Antennas Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 832 KB |
| Title: | W-band Electronic Focus-Scanning by a Reconfigurable Transmitarray for Millimeter-Wave Imaging Applications |
| Abstract: | A w-band electronic focus-scanning function, which is desired for high-resolution fast-speed millimeterwave imaging systems, is realized by a reconfigurable transmitarray antenna (RTA). As a two-layer structure, each RTA element is integrated with two packaged PIN diodes symmetrically within a limited area (1.6×1.6mm2). When a linearly polarized electromagnetic wave incidents on this reconfigurable element, an orthogonally polarized transmission wave is generated, with the ability of 1-bit phase adjustment (0°/180°). Using this element, a 32×2 reconfigurable transmitarray is designed and fabricated to realize 1-D steerable focal points in a near-distance focal plane. The measured focal points agree well with the design, illustrating the feasibility of the proposed RTA for w-band microwave imaging systems. |
| Author(s): | X. Pan, F. Yang, S. Xu, M. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 5 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 21801 KB |
| Title: | Voxel-Based Inverse Methods |
| File Type: | Conference Paper |
| Issue: | Volume: Nondestructive Evaluation and Materials Characterization Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 97 KB |
| Title: | Vortex Beam Optimization Design of Concentric Uniform Circular Array Antenna with Improved Array Factor |
| Abstract: | In this paper, an improved array factor of the concentric uniform circular array (CUCA) antenna is proposed for the orbital angular momentum (OAM) vortex beam optimization design. From the perspective of the radiation pattern’s power conservation principle, a correction factor is introduced to the conventional array factor of CUCA. Then, based on the improved array factor, by adjusting the rings’ radii parameters of the CUCA, we optimize the vortex beam’s sidelobe level through the generic algorithm (GA). Two different CUCA antenna model are calculated as examples to further illustrate the effectiveness of the improved array factor. Subsequently, an electromagnetic simulation model of two rings CUCA antenna is built at C band for generating low sidelobe vortex beam carrying OAM mode. The electromagnetic simulation model of the designed CUCA antenna is also fabricated and measured. The corresponding antenna far-field vortex beam radiation pattern and near-field vortex wave electric field distributions are measured. The simulation results and the measurement results are in good agreement. The proposed designs of antenna and OAM vortex beam regulation are expected to be used for 5G and 6G communications applications. |
| Author(s): | Q. Feng, Y. Lin, Y. Zheng, L. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 7 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1726 KB |
| Title: | VOLUME LOADING -- A NEW PRICIPLE FOR SMALL ANTENNAS |
| Abstract: | Volume loading means placing conductively enclosed volumes at the ends of the arms of a short linear antenna to increase and control the capacitance of the structure. This technique allows tuning the antenna to make it series-resonant at a design frequency for which it is electrically small. This paper describes the discovery and development of the concept, gives some computed examples to illustrate the relation between shape and performance, and describes some experimental work, including a 900 MHx corless phone demonstration design. |
| Author(s): | D.B. Miron, D.B. Miron |
| File Type: | Journal Paper |
| Issue: | Volume: 14 Number: 2 Year: 1999 |
| Download Link: | Click here to download PDF File Size: 662 KB |
| Title: | Voltage Parameter Identification of AC Overhead Transmission Lines by Using Measured Electric Field Data |
| Abstract: | With the development of smart power grids, the demand for real-time voltage monitoring along overhead transmission lines (OTLs) has been growing. However, the existing voltage measurement of OTLs by using potential transformers involves formidable difficulties. This study proposes a non-contact measurement method in which the voltages on AC OTLs are inversely calculated on the basis of the measured data of the power frequency electric field under OTLs. To improve the accuracy and stability of the inverse calculation, an accurate mathematical model and modified inverse algorithms are investigated and then a set of feasible approaches are proposed. First, considering an overhead conductor’s actual physical form and the meteorological conditions of its operating environment, a 3-D catenary model is built, and the mathematical relations between 3-D electric fields and the voltages on OTLs are identified. Second, the improved particle swarm algorithm is used to search the optimal measurement positions of the electric field to improve the ill-posedness of inverse problems. Third, the iterative Tikhonov regularization method, in which the number of iterations is considered as the variable, is adopted to further improve the ill-posedness of inverse problems and reduce the susceptibility of regular solutions to regularization parameter alpha. Fourth, root mean square values and phase parameters of AC voltages are identified from the sinusoidal fitting curves obtained by the real-time inverse calculation. Results of the simulation and experiment examples show that inverse solutions of high precision can be obtained under the condition with relatively high errors of electric field measurement. Moreover, the advantages of the proposed inversion method, such as fast computing speed and good stability, are demonstrated. |
| Author(s): | D. Xiao, Q. Zheng, Y. Xie, Q. Ma, Z. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 8 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1840 KB |
| Title: | Voltage and Current Analysis for Arcing Detection on AC Overhead Electrified Railways |
| File Type: | Conference Paper |
| Issue: | Volume: Numerical Techniques for Electromagnetic Applications Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 135 KB |
| Title: | Vivaldi Antenna for GPR |
| File Type: | Conference Paper |
| Issue: | Volume: Novel Antennas Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 156 KB |
| Title: | Visualizing Time-Domain Distributed Electromagnetic Fields Using Sonnet |
| File Type: | Conference Paper |
| Issue: | Volume: EM Applications in Sonnet Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 755 KB |
| Title: | Visualization of Electric Field Amplitudes inside Porous Spherical Cavity Resonators |
| File Type: | Conference Paper |
| Issue: | Volume: EM Applications using WIPL-D Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 1752 KB |
| Title: | Visualization of Electric and Magnetic Fields Inside Circular and Baffle Waveguides |
| File Type: | Conference Paper |
| Issue: | Volume: S10 Educational Electromagnetics Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 410 KB |
| Title: | Virtual Source Modeling of the High-Frequency Scattering of the Infinite Conducting Strip under Cylindrical Wave Excitation |
| File Type: | Conference Paper |
| Issue: | Volume: Macromodeling for EMC and SI Complex Systems Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 136 KB |
| Title: | Virtual Design of Insulation Elements Based on FEM and Automated Optimization Process |
| File Type: | Conference Paper |
| Issue: | Volume: Hybrid CEM Techniques Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 201 KB |
| Title: | Vibration Isolation of Magnetic Suspended Platform with Double Closed-loop PID Control |
| Abstract: | In magnetic vibration isolation field, magnetic force is used for the isolation, while the whole isolation system is always supported passively, which have non-control shortcomings. Aimed at this problem, a novel active control strategy with a double closed-loop PID algorithm was designed in this paper. The double closed-loop strategy includes an internal and external loop control, which was designed to fulfill the magnetic levitation and isolation, respectively. Firstly, the vibration isolation strategy proposed in this paper was simulated in both time and frequency domain. The simulation results showed that this method possesses good performance of vibration isolation. Then, an active levitation and vibration isolation control experiment was designed. The experimental results showed that the control algorithm has a good vibration control effect under periodic vibration and random vibration conditions. |
| Author(s): | M. Tang, J. Zhou, C. Jin, Y. Xu |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 8 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 2261 KB |
| Title: | Via Modeling in Multi-Gbits/s Signal Analysis |
| File Type: | Conference Paper |
| Issue: | Volume: Black Box Modeling Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 334 KB |
| Title: | VHF-UHF Monocone Antenna for Ground Penetrating Radar Application |
| Abstract: | This paper introduces a VHF-UHF monocone antenna for ground penetrating radar GPR application. The proposed antenna covers different bandwidths through only changing the cone geometry. Same ground plane shape and feeding system are used. Firstly, both conventional and proposed monocone antennas are designed, simulated and their simulated results are compared. One antenna cone is fabricated and measured for verification purpose. Good agreement is obtained between measured and simulated bandwidths. The measured bandwidth extends from 73 MHz to 500 MHz. Secondly, another antenna cone is designed and simulated without altering the upper or the lower cone radii. The second cone antenna bandwidth extends from 130 MHz to 1000 MHz. The receiver antenna of the commercial SIR 2000 impulse GPR is replaced by the proposed VHF-UHF first monocone antenna and the field test results are recorded and discussed. |
| Author(s): | T. G. Abouelnaga, E. A. Abdallah |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 5 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1931 KB |
| Title: | VHF Antennas on Unmanned Air Vehicles (UAV) for a Simplified Synthetic Aperture Radar (SAR) |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Simulation using FEKO Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 506 KB |
| Title: | VHF Antenna Modeling for Rocket Application |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling using FEKO – I Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 182 KB |
| Title: | VFD Approach to the Computation TE and TM Modes in Elliptic Waveguide on TM Grid |
| File Type: | Conference Paper |
| Issue: | Volume: Finite Difference Methods Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 351 KB |
| Title: | VFD Approach to the Computation TE and TM Modes in Elliptic Waveguide on TM Grid |
| Abstract: | We describe here a vector finite difference approach (VFD) to the evaluation of eigenvalues and modes of elliptical waveguides. The FD is applied using a 2D elliptical grid in the waveguide section. A suitable Taylor expansion of the vector mode function allows to take exactly into account the boundary condition. To prevent the raising of spurious modes, our FD approximation results in a constrained eigenvalue problem, that we solve using a decomposition method. This approach has been evaluated comparing our results to known data for the elliptic case. |
| Author(s): | A. Fanti, G. Montisci, G. Mazzarella, G. A. Casula |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 12 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 515 KB |
| Title: | Versatile Nanoparticle Manipulation with Designer Thermoplasmonic Metasurface |
| File Type: | Conference Paper |
| Issue: | Volume: S48 Computational Nanophotonics: Advanced Numerical Methods and Applications II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 1011 KB |
| Title: | Verifying Received Power Predictions of Wireless InSite Software in Indoor Environments at WLAN Frequencies |
| Abstract: | This paper introduces a study on verifying received power at WLAN frequencies in indoor environments, Wireless InSite is a popular electromagnetic ray-tracing software which is widely used for predicting channel behaviour in indoor and outdoor environments. The study compares software-generated data with measurements collected through 3rd floor Chesham Building, University of Bradford, at WLAN frequencies, the paper also investigates the effect of changing settings on results accuracy and computational time, and finally, the paper presents a comparison between simulation results with empirical models. |
| Author(s): | H. A. Obeidat, O. A. Obeidat, M. F. Mosleh, A. A. Abdullah, R. A. Abd-Alhameed |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 10 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1903 KB |
| Title: | Verify Microstrip Antenna Using Feature Selective Verification Method |
| File Type: | Conference Paper |
| Issue: | Volume: 4-3-B Antenna Design and Optimization Techniques I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 463 KB |
| Title: | Verification Testing of Multi-Dynamical Solver for Multiferroic Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: S42 Computational Methods Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 433 KB |
| Title: | Verification of the CADRCS RCS tool for NCTR work |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling, Inversion and Applications Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 228 KB |
| Title: | VERIFICATION OF SOFTWARES FOR ELECTROMAGNETIC FIELD ANALYSIS USING MODELS PROPOSED BY INVESTIGATION COMMITTEES IN IEE OF JAPAN |
| Abstract: | In order to investigate methods for analyzing electromagnetic fields and to compare the accuracy and the CPU time of various codes and so on, investigation committees were set up in IEE of Japan. In this paper, the activities of various investigation committees relating electromagnetic field analysis are described from the viewpoint of the verification of software. [Vol. 12, No. 3 (1997), pp 50-61 |
| Author(s): | Norio Takahashi, Norio Takahashi |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 3 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 793 KB |
| Title: | Verification of Nonlinear Characteristics of Radar Angular Glint by Surrogate Data Method |
| Abstract: | In this paper, we present a nontrivial verification of nonlinear characteristics of angular glint by the surrogate data method. Glint is a key cause of target loss in radar detections. Prediction and suppression of glint is a hot topic. Firstly, glint data of a typical target are calculated by GRECO method for two motions. As glint is calculated by quadric surface calculations, it is nonlinear in mathematical nature. The surrogate data method is explained and workflow is summarized to verify the nonlinear traits of glint. Surrogate methods of phase randomized Fourier transform and amplitude adjusted Fourier transform are illustrated. Test statistics of higher order moments and time reversibility are given. Lorenz model is simulated as a standard nonlinear model to verify effectiveness of workflow, and nonlinear verification criteria are drawn. A new parameter is designed to measure the powerfulness of nonlinearity. Finally, nonlinear verifications for the two angular glint series are given. Results are illustrated in figures and data and they agree with nonlinear criterion. This paper lays the foundations for chaotic verifications of glint. |
| Author(s): | J. Zhang, Z. Li, C. zheng, J. Miao |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 10 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 997 KB |
| Title: | Vectorial GO and Diffraction Decomposition of Physical Optics Scattering of Dipole Wave from Planar Surfaces in Terms of Modified Edge Representation Line Integrals |
| File Type: | Conference Paper |
| Issue: | Volume: Asymptotic and High Frequency Techniques Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 467 KB |
| Title: | Vector Parabolic Equation Modeling of Wireless Propagation in Tunnels with Statistically Rough Surface Walls |
| File Type: | Conference Paper |
| Issue: | Volume: S59 Uncertainty Quantification and Modeling for Complex Applications Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 524 KB |
| Title: | Vector Parabolic Equation Modeling of Wireless Propagation in Tunnels with Statistically Rough Surface Walls |
| File Type: | Conference Paper |
| Issue: | Volume: S10 Student Paper Competition II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 524 KB |
| Title: | Vector Parabolic Equation Method for the EM Scattering from PEC Objects in Half-Space |
| Abstract: | The vector parabolic equation method was widely used to analyze the electromagnetic scattering from electrically large PEC objects in free space. In this paper, it is applied for the analysis of the electromagnetic scattering from PEC objects in halfspace. By introducing both the incident field and the reflected field to illuminate the objects, the vector parabolic equation method can be used to efficiently calculate the radar cross-section of PEC objects with electrically large size in half-space. The numerical results demonstrate that the proposed method can efficiently give reasonably accurate results. |
| Author(s): | Z. He, T. Su, R. S. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 8 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1155 KB |
| Title: | Vector Control of PMSM Take Over by Photovoltaic Source |
| Abstract: | This article established with the modeling and the field oriented control of permanent magnet synchronous machines, with a focus on their applications in variable speed domain in photovoltaic source. |
| Author(s): | T. Yuvaraja, K. Ramya |
| File Type: | Express Journal Paper |
| Issue: | Volume: 1 Number: 6 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2266 KB |
| Title: | Vector Control of PMSM Take Over by Photovoltaic Source |
| Abstract: | This article established with the modeling and the field oriented control of permanent magnet synchronous machines, with a focus on their applications in variable speed domain in photovoltaic source. |
| Author(s): | T. Yuvaraja, K. Ramya |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1641 KB |
| Title: | Vector Control of PMSM Take Over by Photovoltaic Source |
| Abstract: | This article established with the modeling and the field oriented control of permanent magnet synchronous machines, with a focus on their applications in variable speed domain in photovoltaic source. |
| Author(s): | T. Yuvaraja, K. Ramya |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1641 KB |
| Title: | VARIOUS APPROACHES TO TORQUE CALCULATIONS BY FEM AND BEM |
| Abstract: | Different algorithms for the torque calculation by Maxwell stress method (MSM) are dealt with in the paper. The aim of designing these algorithms was to reduce the influence of the choice of the integration path and discretization of the air gap between the stator and rotor on the accuracy of the results. In some of these algorithms the connection between the stator and rotor is released For the magnetic field calculation the finite element method (FEM), boundary element method (BEM), and hybrid finite element - boundary element method (HM) were used. The calculation results were tested on a permanent magnet DC motor and a single phase brushless motor. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 127-130] |
| Author(s): | Mladen Trlep, Anton Hamler, Bozidar Hribernik, Mladen Trlep, Anton Hamler, Bozidar Hribernik |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 321 KB |
| Title: | Variational Analysis of Substrate-Integrated Waveguides with Longitudinal Slot |
| File Type: | Conference Paper |
| Issue: | Volume: S43 Advanced Applications I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 290 KB |
| Title: | Variable Phase-Shifter/Down Converter for Active Microstrip Phased Array Antenna Applications |
| File Type: | Conference Paper |
| Issue: | Volume: Poster Sessions 1 Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 1063 KB |
| Title: | Validity of Approximate Boundary Conditions in Analysis of Strip-Loaded Planar and Curved Surfaces |
| File Type: | Conference Paper |
| Issue: | Volume: Poster Sessions 1 Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 286 KB |
| Title: | Validation, Verification and Calibration in Applied Computational Electromagnetics |
| Abstract: | Model validation, data verification, and code calibration (VV&C) in applied computational electromagnetics is discussed. The step by step VV&C procedure is given systematically through canonical scenarios and examples. Propagation over flat-Earth with linearly decreasing vertical refractivity profile, having an analytical exact solution, is taken into account as the real-life problem. The parabolic wave equation (PWE) is considered as the mathematical model. MatLab-based numerical simulators for both the split step Fourier and finite element implementations of the PWE are developed. The simulators are calibrated against analytical exact and high frequency asymptotic solutions. Problems related to the generation of reference data during accurate numerical computations are presented. |
| Author(s): | G. Apaydin, L. Sevgi |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 1225 KB |
| Title: | Validation, Verification and Calibration in Applied Computational Electromagnetics |
| File Type: | Conference Paper |
| Issue: | Volume: CEM for EM Education Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 755 KB |
| Title: | VALIDATION OF, AND LIMITATIONS ON, THE USE OF NEC-4 FOR RADIATION FROM ANTENNAS BURIED WITHIN A HOMOGENEOUS HALF-SPACE |
| Abstract: | The use of the computer program NEC-4 for the simulation of radiation from buried antennas is considered. NEC-4 uses the “exact” Sommerfield integral formulation for stratified media (in NEC-4, re-stricted to an homogeneous half-space). Although the formulation is rigorous, certain approximations have to be made for numerical implementation. The formu-lation, and some of these issues, is outlined in the paper. Several validation examples comparing results computed using NEC-4 and results available in the lit-erature are presented for antennas buried in various typical media, including ground, fresh water, and the sea. Satisfactory agreement has generally been obtained; where differences have been noted, we have able to explain most in terms of approximate implementa-tion issues. |
| Author(s): | David B. Davidson, H. du Toit Mouton, David B. Davidson, H. du Toit Mouton |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 3 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 554 KB |
| Title: | Validation of Wind Turbine Doppler Signatures in a Passive Bistatic Radar with a Point Scatterer Model |
| File Type: | Conference Paper |
| Issue: | Volume: S06 Advanced Radar Technologies and Techniques I Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 961 KB |
| Title: | VALIDATION OF THE NUMERICAL ELECTROMAGNETICS CODE (NEC) FOR ANTENNA WIRE ELEMENTS IN PROXIMITY TO EARTH |
| Abstract: | This paper summarizes recent MITRE efforts to validate the NEC-3 and NEC-GS versions of the Numerical Electromagnetics Code (NEC) developed by Lawrence Livermore National Laboratory for predicting the performance of antenna wire elements in close proximity to flat earth. In an early version (NEC-l), the effect of the air-ground interface was included by applying a plane-wave Fresnel rei:lection coefficient approximation to the field of a point source. The NEC-2 version, while still retaining the Fresnel reflection coefficient model as an option, provides a more accurate ground model by numerically evaluating Sommerfeld integrals. The version NEC-3 extends the NEC-2 version to cases for bare wire segments below the air-earth interface. Version NEC-GS utilizes rotational symmetry to provide a more efficient version of NEC-3 for the case of a monopole element with a uniform radial wire ground-screen (GS). Results of the various versions are compared with each other and with other mndels. The input-output format of the NEC-GS version is discussed. It is concluded that the NEC-3 Sommerfeld integral option in the NEC-GS version is the best available model for monopole elements with electrically small radial-wire ground planes. [Vol. 8, No. 2 (1993), pp 44-71] |
| Author(s): | M. M. Weiner, M. M. Weiner |
| File Type: | Journal Paper |
| Issue: | Volume: 8 Number: 2 Year: 1993 |
| Download Link: | Click here to download PDF File Size: 1395 KB |
| Title: | VALIDATION OF THE MININEC3 CODE FOR COMPLEX RADIATING STRUCTURES |
| Abstract: | The ability of the MININEC3 code to accurately model complex radiating structures was previously unknown because computer compiler constraints limited the size of analyzable configuration. With the conversion of the code from BASIC to FORTRAN however it is now feasible to use it to simulate such structures. This paper presents the results of a validation exercise aimed at assessing the code's suitability for modelling configurations which involve hundreds of segments. [Vol. 9, No. 1 (1994), pp 58-66] |
| Author(s): | K.P. Murray, B.A. Austin, K.P. Murray, B.A. Austin |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 1 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 771 KB |
| Title: | Validation of Fast Site-Specific Mean-Value Models for Indoor Propagation |
| Abstract: | A fast assessment of the local mean value of the electric field strength throughout a floor plan is useful for the design of local-area networks. Site-specific models require coding the location of walls, doorways, and other features and modelling their structure and electrical properties. Using ray tracing to find the field strength throughout the floor plan is slow and expensive because a grid of closely-spaced points is needed to trace the rapid variations called fast fading; then the raytracing local area average is found by explicit spatial averaging, to obtain the slow fading behavior. The raytracing mean value is obtained by combining the amplitudes of the fields associated with the rays on an energy basis; widely-spaced grid points can be used because the local mean value varies slowly with position, making the calculation fast and inexpensive. The Sabine method provides a energy-balance approach for an inexpensive estimate of the local mean value field strength. This paper tests the accuracy of the fast methods (the ray-tracing mean value and the Sabine mean value) against the local area average found from dense ray tracing, and against measurements. In a 40 m2 room of roughly square floor plan, the fields from the fast methods were close to those of dense ray tracing and to the measurements. But it is shown that in a long corridor, the ray-tracing mean value and the Sabine mean value were low compared to dense ray tracing, and so these fast methods should be used with caution. |
| Author(s): | C. W. Trueman, D. Davis, B. Segal, W. Muneer |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 3 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 264 KB |
| Title: | Validation of a Z-Matrix Finite Element Program for Analyzing Electrostatic Fields |
| Abstract: | Modern electrical equipment designs demand more compact, complex geometries and require more strigent analyses of the associated three-dimensional electrostatic fields. Analytical solutions of such fields are limited to relatively simple geometries. Numerical solutions using the finite element method are limited by available computer storage and processing time. Lauber posed an economical method for solving three-dimensional finite element electrostatic fields by forming the finite element system matrix using Brown's Z-matrix techniques. (Lauber, 1982) (Brown, 1975) This method was implemented by a FORTRAN computer program. (Barber and Lauber, 1986) (Barber, 1988) The purpose of this paper is to briefly describe the present version of the program called FEWZ (Finite Elements using a Windown and the Z-matrix) and to show how it was validated. |
| Author(s): | P.F. Barber, T.S. Lauber, E.D. Patterson, P.F. Barber, T.S. Lauber, E.D. Patterson |
| File Type: | Journal Paper |
| Issue: | Volume: 4 Number: 3 Year: 1989 |
| Download Link: | Click here to download PDF File Size: 945 KB |
| Title: | VALIDATION AND DEMONSTRATION OF FREQUENCY APPROXIMATION METHODS FOR MODELING DISPERSIVE MEDIA IN FDTD |
| Abstract: | Recently, digital signal processing techniques were used to design, analyze and implement discrete models of polarization dispersion for the Finite-Difference Time-Domain (FDTD) method. The goals of the present work are to illustrate the FDTD update equations for these techniques and to validate and demonstrate these techniques for one-dimensional problems involving reflections from dispersive dielectric half-spaces. Numerical results are compared with several other dispersive medial FDTD implementations. |
| Author(s): | J.H. Beggs, J.H. Beggs |
| File Type: | Journal Paper |
| Issue: | Volume: 14 Number: 2 Year: 1999 |
| Download Link: | Click here to download PDF File Size: 484 KB |
| Title: | Validating the Magnetostatic Frill Source with WIPL-D |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Simulation using Wipl-D Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 267 KB |
| Title: | Validating Numerical Models – Quantifying Error |
| Abstract: | |
| Author(s): | |
| File Type: | Newsletter Paper |
| Issue: | Volume: 19 Number: 1 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 107 KB |
| Title: | Valence Electron High-harmonic Generation Analysis by the Finite Difference Time Domain Method |
| File Type: | Conference Paper |
| Issue: | Volume: 2-2-A Multiphysics Modeling and Simulation Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 162 KB |
| Title: | V-Band Frequency Reconfigurable Cavity-Based Bandpass Filters |
| File Type: | Conference Paper |
| Issue: | Volume: S55 Nanotechnology Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 410 KB |
| Title: | V Transmission lines Frequency Operation Band |
| File Type: | Conference Paper |
| Issue: | Volume: Microwave, Optical Devices, and Propagation Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 384 KB |
| Title: | UWB-MIMO Quadruple with FSS-Inspired Decoupling Structures and Defected Grounds |
| Abstract: | In this paper, a quad element Ultra Wideband Multiple-Input Multiple-Output (UWB-MIMO) antenna system is presented. The proposed design is compact as it has four semielliptical shaped antennas along with the decoupling structures, fabricated on a compact substrate. The substrate employed is a low cost FR-4 laminate. The antenna elements are decoupled by employing Defected Ground Structures (DGS) and structures inspired from Frequency Selective Surfaces. An enhanced impedance match over lower to medium band is achieved by introducing dipole-like parasitic stubs on rear sides of the antennas. Measured results show that the isolation achieved by the proposed design is more than 20 dB over desired frequency band. |
| Author(s): | T. Shabbir, R. Saleem, A. Akram, F. Shafique |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 2 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1186 KB |
| Title: | UWB Square Monopole Antenna with Omni-Directional Radiation Patterns for Use in Circular Cylindrical Microwave Imaging Systems |
| Abstract: | In this paper, a novel ultra-wideband printed monopole antenna (PMA) for the use in a circular cylindrical microwave imaging system is presented. The proposed antenna consists of a square radiating patch and a ground plane with a pair of L-shaped slots and two L-shaped conductor back plane, which provides a wide usable fractional bandwidth of more than 130 % (3.02 GHz - 15.21 GHz). By cutting two modified Lshaped slots with variable dimensions on the ground plane corners and also by inserting two Lshaped conductor back plane on the other side of the substrate, additional resonances are excited and hence much wider impedance bandwidth can be produced, especially at the higher band. The proposed antenna has an ordinary square radiating patch, therefore displays a good omni-directional radiation pattern even at higher frequencies, and also its radiation efficiency is greater than 82% across the entire radiating band. The designed antenna has a small size of 12 × 18 mm2. Simulated and measured results are presented to validate the usefulness of the proposed antenna structure for circular cylindrical microwave imaging system. |
| Author(s): | N. Ojaroudi, M. Ojaroudi, N. Ghadimi, M. Mehranpour |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 2 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 542 KB |
| Title: | UWB Slot Antenna with Band-Stop Operation by Using H-Shaped Parasitic Structures for UWB Applications |
| Abstract: | A novel ultra wideband (UWB) printed slot antenna with band-notched performance is designed and manufactured. In order to increase the impedance bandwidth of the slot antenna, we use a rectangular slot with an H-shaped parasitic structure inside the rectangular slot on the feedline that with this structure UWB frequency range can be achieved. Additionally, by using a square ring radiating stub with a rotated H-shaped parasitic structure inside the square ring, a frequency band-stop performance has been obtained. The designed antenna has a small size of 20 × 20 mm2 while showing the radiation performance in the frequency band of 2.97 GHz to over 12.39 GHz with a band rejection performance in the frequency band of 5.01 GHz to 5.98 GHz. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the UWB frequency range. |
| Author(s): | M. Ojaroudi, N. Ojaroudi, N. Ghadimi |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 12 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 448 KB |
| Title: | UWB Slot Antenna with Band-Notched Property with Time Domain Modeling based on Genetic Algorithm Optimization |
| Abstract: | This paper presents a kind of band-notched slot antenna with time domain designing method for ultra-wideband (UWB) applications. The proposed antenna consists of a square radiating stub with a defected mircostrip feed-line using an M-shaped step impedance resonator (SIR) slot and a defected ground plane with a pair of inverted U-shaped slots. By cutting two inverted U-shaped slots in the ground plane, a new resonance at the higher frequencies is excited and hence much wider impedance bandwidth can be produced that. To generate a band-notched characteristic, we use an M-shaped slot at the feed-line. The proposed antenna can operate from 3.03 to 13.21 GHz with frequency band-notched function in 7.28-7.79 GHz to avoid interference from downlink of X-band satellite communication systems. To verify the validation of the proposed antenna an equivalent circuit based on time domain reflectometry (TDR) analysis is presented. In addition, the accuracy of the equivalent circuit models have been improved using Genetic algorithm optimization (GAP). Detailed simulation and numerical investigations are conducted to understand their behaviors and optimize for broadband operation. The proposed antenna exhibits almost omni-directional radiation patterns in UWB frequency range and could be used in wireless systems. |
| Author(s): | J. Zolghadr, Y. Cai, N. Ojaroudi |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 8 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1770 KB |
| Title: | UWB Sampler for Wireless Communications and Radar |
| File Type: | Conference Paper |
| Issue: | Volume: Technologies for Ultra-Wideband Communication Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 167 KB |
| Title: | UWB Monopole Antenna with WLAN Frequency Band-Notched Performance by using a Pair of E-Shaped Slits |
| Abstract: | In this paper an ultra-wideband monopole antenna with frequency band-stop performance is designed and manufactured. The proposed antenna consists of square radiating patch with two E-shaped slits and a ground plane with a protruded T-shaped strip inside the rectangular slot. In the proposed structure, by inserting a rectangular slot with a T-shaped strip protruded inside the slot on the ground plane, additional resonance is excited and hence, much wider impedance bandwidth can be produced, especially at the higher band. In order to create band-rejected function we use two E-shaped slits in the square radiating patch. The fabricated antenna has the frequency band of 3 GHz to over 12.7 GHz with a rejection band around 5 GHz – 6 GHz. Good VSWR and radiation pattern characteristics are obtained in the frequency band of interest. Simulated and measured results are presented to validate the usefulness of the proposed antenna structure for UWB applications |
| Author(s): | N. Ojaroudi, M. Ojaroudi, N. Ghadimi |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 12 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 403 KB |
| Title: | UWB Monopole Antenna with Switchable Band-Notch Characteristic Using a Novel MEMS Afloat |
| Abstract: | In this paper, a novel microelectro-mechanical system (MEMS) U-shaped afloat is designed and used instead of a simple slot to activate and deactivate the band notch characteristic of an ultra wideband (UWB) monopole antenna at the WLAN band (5.15-5.825 GHz) without extra DC bias lines. The novelty of this work is design of MEMS afloat that can stay in down state permanently. When the dc actuation voltage, about 20 volts, is applied to the microstrip center line, the ?/2 long U-shaped afloat moves down and creates a slot (resonating element) in its vacant place. Whereas no voltage is applied, the afloat remains in the up position and serves as a part of the antenna, which eliminates the resonance. The proposed design for MEMS afloat has least negative effect on gain, reflection coefficient, and pattern of the antenna. The gain of the antenna is about 3.2 dBi over the entire UWB frequency band (3.1-10.6 GHz), while it decreases sharply over 7 dB at the rejection band. More-over, the time-domain characteristics of the antenna is investigated, which shows 1 ns delay over the UWB frequency band for 20 cm. Due to a novel afloat design, the addition of the resonance element does not affect on the radiation performance, reflection coefficient, gain, and group delay of the antenna outside of notched band frequencies. |
| Author(s): | A. Nemati, B. A. Ganji |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 12 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1070 KB |
| Title: | UWB Monopole Antenna with Dual Band-Stop Performance Using G-Shaped SRR and SIR Structures at Feed Line |
| Abstract: | This article presents a new design of ultra-wideband monopole antenna with the characteristics of dual band rejection .The antenna consists of a circular radiating patch, a feed-line with G-shaped Step-Impedance Resonator (SIR) slot and Split-Ring Resonator (SRR) structure, and a ground plane which provides a wide usable fractional bandwidth of more than 120% with two notch bands around 5.15-5.35 GHz and 7.25-7.75 GHz, to avoid interferences from High Performance Radio Local Area Networks (HIPERLAN) and downlink frequency of X-band satellite systems. The simulated and measured results show that the antenna design exhibits an operating bandwidth (VSWR<2) from 2.86 to 12.92 GHz, excluding the rejected bands. The proposed antenna configuration is simple, easy to fabricate and can be integrated into any UWB system. The antenna has an ordinary circular-disc radiating patch, therefore displays good omnidirectional radiation patterns, even at higher frequencies. |
| Author(s): | S. Ojaroudi, Y. Ojaroudi, N. Ghadimi, N. Ojaroudi |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 10 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 761 KB |
| Title: | UWB Monopole Antenna with Dual Band-Notched Function |
| Abstract: | In this letter, an Ultra-Wideband (UWB) monopole antenna with dual frequency band-stop performance is designed and manufactured. In the proposed structure, by inserting an S-shaped parasitic structure inside a square slot in the ground plane a new resonance at higher frequencies can be achieved, which provides a wide usable fractional bandwidth of more than 125%. In order to generate dual bandnotched function, we use four L-shaped strips protruded inside square ring. The measured results reveal that the antenna offers a very wide bandwidth from 2.63 to 14.2 GHz with two notched bands covering all the 5.2/5.8 GHz WLAN, 3.5/5.5 GHz WiMAX and 4 GHz C bands. Good VSWR and radiation pattern characteristics are obtained in the frequency band of interest. |
| Author(s): | Y. Ojaroudi, S. Ojaroudi, N. Ojaroudi |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 2 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 523 KB |
| Title: | UWB Monopole Antenna with Compact Polygon-Shaped Patch for Portable Devices |
| Abstract: | In this paper, a small ultra wideband (UWB) antenna with co-planar waveguide (CPW) feed, consisting of a polygon-shaped design on the patch and a ground plane truncated with two mirror rectangular–shaped notches is designed for ultra wideband (UWB) applications. In this proposed antenna, through increasing the number of cuts inside the initial patch, a proper control on the upper frequency of the band can be achieved. The overall dimension of the antenna is 19×19 ×1 mm3 and fed by 50 ? coplanar waveguide. The proposed antenna is developed and its VSWR is compared with the simulated result. The proposed antenna operates in the adopted bandwidth (3.1 GHz-10.6 GHz) with VSWR < 2, and covers it very well from 3 GHz to 14.9 GHz, which provides fractional bandwidths of more than 132%. The effect of the ground plane notch on the optimization of the VSWR is discussed in detail. |
| Author(s): | T. Sedghi, V. Rafii, M. Moosazadeh |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 1 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 900 KB |
| Title: | UWB MIMO Antenna with Decoupling Strip for 5G Applications |
| File Type: | Conference Paper |
| Issue: | Volume: S47 Advanced Antenna Designs for Emerging Wireless Applications Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 624 KB |
| Title: | UWB MIMO Antenna for High Speed Wireless Applications |
| Abstract: | The paper proposes a MIMO antenna composed of two elements in the form of UWB monopole antennas. Polarization diversity of the proposed antenna is obtained locating the two elements perpendicularly on a common substrate. Also the isolation between elements is accomplished without using any extra decoupling structures. The two monopoles antennas with half elliptical shape are fed with asymmetric coplanar strip (ACS). The presented antenna is located on substrate 48 × 28 mm2 in total size. The distance between the two elements is 15 mm that is 0.15λ0 at 3GHz. The antenna was designed to work effectively from 3 to 11.5 GHz with reflection coefficient better than -10 dB and isolation lower than 18 dB. In addition, antenna with elements located in parallel was designed to show the advantage of the original design. Envelope correlation coefficient, diversity gain and channel capacity loss document the antennas behavior. The antenna was fabricated and measured. Measurement validated the simulation and showed that the designed antenna can be well applied in UWB MIMO systems. |
| Author(s): | A. A. Ibrahim, J. Machac, R. M. Shubair |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 9 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1778 KB |
| Title: | UWB Microstrip-Fed Slot Antenna with Band-Rejection Performance Using an SRR Conductor-Backed Plane |
| Abstract: | In this article, a novel and compact ultra-wideband (UWB) slot antenna with bandnotched function is presented. This antenna consist of a square radiating stub, a 50? microstrip feedline, a ground plane with a pair of rotated Tshaped strips protruded inside square slots and a Split Ring Resonator (SRR) conductor-backed plane. In this design, by cutting a pair of modified square slots with rotated T-shaped strips protruded inside slots, additional resonance is excited and hence much wider impedance bandwidth can be produced. In order to achieve a band-notched function, an SRR parasitic structure was inserted in the ground plane. The measured results show that the proposed antenna can achieve the Voltage Standing Wave Ratio (VSWR) requirement of less than 2.0 in frequency range from 3.1 GHz to 13.15 GHz, with band-rejection performance of 5.08 GHz to 6 GHz, to avoid interference from WLAN communications. The presented microstrip-fed slot antenna exhibits good radiation behavior. The antenna has a small size. |
| Author(s): | N. Ojaroudi, N. Ghadimi, Y. Ojaroudi |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 3 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 691 KB |
| Title: | UWB Gain Enhancement of Horn Antennas Using Miniaturized Frequency Selective Surface |
| Abstract: | In this work, enhancement of the radiation performances of horn antennas are worked out within their operation bandwidth by placing the miniaturized Frequency Selective Surface (FSS)s perpendicularly into the inner part of their flares. Here each FSS consists of only a single miniaturized double-sided inverted Tshaped square unit cell designed on the low-cost FR4 with relative permittivity 4.4, loss tangent 0.0035 and thickness 1.58 mm in 3D CST environment so that it is able to focus the propagating electromagnetic waves to increase the directivity properties like a dielectric lens, while keeping the mismatching characteristics with less size and low manufacturing cost compared to its counter parts. Herein an exponentially tapered TEM horn with the operation bandwidth of 5-13 GHz is taken as an example horn antenna for measurements. From the measured results of the prototyped module, it can be observed that the proposed module keep mismatching characteristics of the horn antenna, meanwhile the gain and beam widths are enhanced to amplify the signal in the operation band without any increase in the total volume of the module or making the design bulky. Thus, it is expected that this methodology can be implemented to horn antennas effectively reducing volume and cost of communication systems. |
| Author(s): | M. A. Belen, F. Gunes, P. Mahouti, A. Belen |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 9 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2272 KB |
| Title: | UWB Compact TEM Ridged Horn Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Application of Electromagnetic Simulation for Designing and Analysis of Antennas and Radio Propagations Part I Number: Year: 2014 |
| Download Link: | Login To Download (For Members) File Size: 322 KB |
| Title: | Utilizing Particle Swarm Optimization in the Field Computation of Non-Linear Magnetic Media |
| Abstract: | It is well known that the computation of magnetic fields in nonlinear magnetic media my be carried out using various techniques. In the case of problems involving complex geometries or magnetic media, numerical approaches become especially more appealing. The purpose of the paper is to present an automated particle swarm optimization approach using which field computations may be carried out |
| Author(s): | A. A. Adly, S. K. Abd-El-Hafiz, A. A. Adly, S. K. Abd-El-Hafiz |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 3 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 222 KB |
| Title: | Utilizing Hybrid Dielectric-Metal and Mesh Refinement Techniques When Modeling a MMIC in Concerto Quickwave |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling with QuickWave/Concerto Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 344 KB |
| Title: | Utilization of Protruded Strip Resonators to Design a Compact UWB Antenna with WiMAX and WLAN Notch Bands |
| Abstract: | In this paper, a new design of ultrawideband (UWB) microstrip monopole antenna is presented. The main novelty of the proposed structure is the using of protruded strips as resonators to design an UWB antenna with dual band-stop property. In the proposed design, by cutting the rectangular slot with a pair of rotated Y-shaped strips in the ground plane, additional resonance is excited and much wider impedance bandwidth can be achieved. To make a single band-notched function, the square radiating patch is converted to the square-ring structure with a pair of protruded fork-shaped strips. Finally, by cutting a rectangular slot with a protruded M-shaped strip at the feed line, a desired dual band-notched function is achieved. The measured results reveal that the presented dual band-notched antenna offers a very wide bandwidth from 2.8 to 11.6 GHz, with two notched bands, around of 3.3-3.7 GHz and 5-6 GHz covering all WiMAX and WLAN bands. |
| Author(s): | J. Mazloum, N. Ojaroudi |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 2 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 684 KB |
| Title: | UTD Shooting-and-Bouncing Extension to a PO/PTD Ray Tracing Algorithm |
| Abstract: | This paper deals with the efficient combination of three well-established electromagnetic modeling methods, a Shooting-and-Bouncing-Rays (SBR) algorithm on the basis of the Geometrical Optics (GO), a source-based calculation of scattered field strengths using Physical Optics (PO) and Physical Theory of Diffraction (PTD), and diffraction calculation on the basis of the Uniform Theory of Diffraction (UTD). While the conventional GO-PO/PTD methods are able to accurately calculate wedge contributions to scattered fields, the further propagation of diffracted rays is generally not considered in SBR approaches. Thus, the aim of this paper is to describe the implementation of diffracted rays according to the UTD concept into an SBR code. This novel implementation allows for the modeling of double diffraction and reflected-diffractedreflected paths in complex scenarios consisting of a very large number of surface elements as well as the accurate simulation of cavities. The comparison with numerically exact reference simulations proves that the proposed hybrid GO/UTD-PO/PTD algorithm yields excellent results and that the UTD-SBR extension definitely improves the simulations of the ray tracing algorithm also for realistic objects. |
| Author(s): | F. Weinmann |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 3 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 526 KB |
| Title: | UTD Ray and Beam Methods for Analysis of Large EM Wave Problems Abstract |
| File Type: | Tutorial Abstract |
| Issue: | Volume: S35 UTD Ray and Beam Methods for Analysis of Large EM Wave Problems Number: Year: 2015 |
| Download Link: | Login To Download (For Members) File Size: 92 KB |
| Title: | Using YATPAC for Modeling of a Marchand Balun |
| File Type: | Conference Paper |
| Issue: | Volume: MEFiSTo Modeling and Analysis Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 189 KB |
| Title: | Using Transfer Function Approach To Develop MRI Visible and Low RF Heating Sleeve for Cardiac Applicaion |
| File Type: | Conference Paper |
| Issue: | Volume: S54 Computational Electromagnetic Modeling in EMC Applications Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 300 KB |
| Title: | 3B-SPLINES IN THE INTEGRAL EQUATION SOLUTION FOR SCATTERING FROM BODIES OF REVOLUTION |
| Abstract: | The use of B-Splines functions is investigated in conjunction with the Method of Moments integral-equation solution to the problem of scattering from conducting bodies of revolution. Its computational performance in terms of relative accuracy and storage/CPU time requirements is evaluated against entire-domain and sampling-like basis functions. Particular attention is given to the description of current near edges. Questions of time (space) and frequency (wavenumber) localization are also addressed. A simple scheme devised to enforce boundary conditions a priori is shown to potentially capable to stgabilize otherwise spurious solutions |
| Author(s): | F.L. Teixeira, J.R. Bergmann, F.L. Teixeira, J.R. Bergmann |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 532 KB |
| Title: | ELECTROMAGNETIC PROPERTIES OF A CHIRAL-PLASMA MEDIUM |
| Abstract: | The theoretical properties of a composite chiral-plasma medium are devel- oped. Using the reaction theorem, we obtain the proof of nonreciprocity based upon the constitutive relationships between the electromagnetic vectors E, B, H, D. Using the Maxwell's equations and the proposed constitutive relations for a chiral- plasma medium, we derive the E, and H, vector equations and from these equations, dispersion relations and E-field polarizations are found. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 14-18] MTRT - A MODIFIED TRANSVERSE RESONANCE TECHNIQUE |
| Author(s): | Hector Torres-Silva, Norma Reggiani, Paulo H. Sakanaka, Hector Torres-Silva, Norma Reggiani, Paulo H. Sakanaka |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 283 KB |
| Title: | MTRT - A MODIFIED TRANSVERSE RESONANCE TECHNIQUE |
| Abstract: | In this work a modified formulation of the transverse resonance technique (TRT) is presented. The difference between the usual TRT and the formulation presented here, MTRT, is the equivalent network considered. With the MTRT proposed formulation, mode solution identification requires less arduous work. The complete equation set is described. Numerical results are presented for dispersion characteristics of microstrip lines, coupled microstrip lines and conductor-backed coplanar waveguides (CBCW). When compared to results obtained by other methods, a good agreement is observed. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 19-25] |
| Author(s): | Alfredo Gomes Neto, Creso S. da Rocha, Herve' Aubert Aubert, D. Bajon, H. Baudrand, Alfredo Gomes Neto, Creso S. da Rocha, Herve' Aubert Aubert, D. Bajon, H. Baudrand |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 303 KB |
| Title: | EFFECT OF THE MAGNETIC ANISOTROPY ON THE CHARACTERISTICS OF MICROSTRIP ANTENNAS WITH SEVERAL LAYERS |
| Abstract: | The main objective of this work is to show how the properties of a ferrimagnetic material change the characteristics of a microstrip patch with several layers. Particularly, it is investigated how the resonant frequency and the radiation pattern are changed by varying the ferrimagnetic layer thickness or the magnitude and/or direction of the external applied magnetic field. The analysis is carried on by using Hertz potentials and Galerkin method. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 26-29] |
| Author(s): | Jose de Ribamar Silva Oliveira, Adaildo Gomes d'Assunc o, Jose de Ribamar Silva Oliveira, Adaildo Gomes d'Assunc o |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 244 KB |
| Title: | DISPERSIVE ANALYSIS OF CIRCULAR CYLINDRICAL MICROSTRIPS AND BACKED SLOTLINES |
| Abstract: | In this work, the full-wave analysis of circular cylindrical microstrips and backed slotlines is performed, by using a combination of Hertz vector potentials and Galerkin method. The analysis is developed in the spectral domain. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 30-33] |
| Author(s): | Laercio Martins de Mendonca, Adaildo Gomes d'Assunc o, Laercio Martins de Mendonca, Adaildo Gomes d'Assunc o |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 268 KB |
| Title: | FINITE ELEMENT ANALYSIS AND EVALUATION OF ELECTROMAGNETIC FIELDS GENERATED BY ATMOSPHERIC DISCHARGES |
| Abstract: | A lightning return stroke channel is modeled by a high loss transmission line. The differential equations that represent its dynamic behavior are solved by the application of the one-dimensional finite element method (FEM). By the combination of FEM results with the use of Maxwell equations applied to the dipole method, electric and magnetic (EM) fields are evaluated at various positions in space. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 34-38] |
| Author(s): | E.H.R Coppoli, R.R. Saldanha, A. Konrad, E.H.R Coppoli, R.R. Saldanha, A. Konrad |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 318 KB |
| Title: | POINT-MATCHED TIME DOMAIN FINITE ELEMENT METHOD APPLIED TO MULTI-CONDUCTOR ELECTROMAGNETIC TRANSIENTS ANALYSIS. |
| Abstract: | A point-matched time domain finite element method (TDFE) applied to the analysis of electromagnetic transients in multi-conductor transmission line network is presented. The TDFE method solves the partial differential transmission line equations based on a semi-discrete approximation using the finite element method and leap-frog scheme. Some oscillations can occur due to the stability condition of the technique. Using the modal analysis these oscillations can be eliminated. A surge propagation in a simple multi-conductor network is presented and the results are compared with the Electromagnetic Transients Program (EMTP) simulations. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 39-43] |
| Author(s): | Glassio Costa de Miranda, Glassio Costa de Miranda |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 319 KB |
| Title: | ERROR ESTIMATORS IN SELF-ADAPTIVE FINITE ELEMENT FIELD CALCULATION |
| Abstract: | The aim of this paper is to present different error estimates to improve accuracy in linear and nonlinear self-adaptive finite element field calculation. The first estimator is based on the polynomial theory, the second one makes an estimation of the flux density divergence, the third one is linked to a magnetomotive force associated to elements sides, and the fourth one is based on the use of the bilinear element. All methods were implemented in our software named LMAG2D developed at "Escola Politecnica da Universitade de S o Paulo", Brazil. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 44-49] |
| Author(s): | L. Lebensztajn, J.R. Cardoso Cardoso, L. Lebensztajn, J.R. Cardoso Cardoso |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 386 KB |
| Title: | TRANSIENT VOLTAGE AND ELECTRIC FIELD DISTRIBUTIONS IN AIR CORE REACTORS |
| Abstract: | This work presents a computational model for the evaluation of transient voltage and longitudinal electric field distributions in single layer air core reactors. The influence of a grounded shielding concentric to the reactor is considered. The validity of the model is verified by comparing computed and measured voltage responses at three taps of a test reactor. Analyses showing the influence of the grounded shielding, front time and front wave shape of the applied voltage on the maximum longitudinal electric stresses along the reactor winding are presented. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 50-55] |
| Author(s): | S. L. Varricchio, N. H. C. Santiago, S. L. Varricchio, N. H. C. Santiago |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 324 KB |
| Title: | CALCULATION OF ELECTRIC FIELD CREATED BY TRANSMISSION LINES, BY 3D-FE METHOD USING COMPLEX ELECTRIC SCALAR POTENTIAL |
| Abstract: | This paper presents a methodology for tridimensional analysis of the electric field produced by transmission lines. It utilizes the complex electric scalar potential, which makes it possible to consider variation of module and phase in the voltages of supply lines. The Finite Element Method (FEM) is applied to solve the differential equation that describes the phenomenon in the domain of this study. Finally, a comparison is established between the results obtained applying the proposed methodology and the values reached through the classical method of charge simulation. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 56-60] |
| Author(s): | Ricardo Marcal Matias, Adroaldo Raizer, Ricardo Marcal Matias, Adroaldo Raizer |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 330 KB |
| Title: | ADAPTIVE FINITE ELEMENT MESH REFINEMENT AND 'A POSTERIORI' ERROR ESTIMATION PROCEDURES FOR ELECTROMAGNETIC FIELD COMPUTATION |
| Abstract: | Adaptive Finite Element (FE) mesh refinement combined with a robust and functionally reliable error estimate provides nearly optimal solution accuracy. The efficiency of adaptivity depends on the effectiveness of the mesh refinement algorithm and also on the availability of a reliable and computationally inexpensive error estimation strategy. An adaptive mesh refinement algorithm utilizing a hierarchical minimal tree based data structure for 2D and 3D problems is discussed in this paper. Two different 'a posteriori' error estimation schemes, one based on the local element by element method and the other using the gradient of field approach are also presented. The usefulness of the mesh refinement algorithm and the error estimation strategies are demonstrated by adaptively solving a set of 2D and 3D linear boundary value problems. The performance of the error estimates is also verified for adaptive modeling of a nonlinear problem involving the design of a permanent magnet synchronous machine. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 61-68 |
| Author(s): | K.C. Chellamuthu, Natan Ida, Q.k. Zhang, K.C. Chellamuthu, Natan Ida, Q.k. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 656 KB |
| Title: | DESIGN OF ELECTRICAL MACHINES AIDED BY FIELD CALCULATION AND FACTORIAL EXPERIMENTS METHOD |
| Abstract: | An approach for electrical machines design by using magnetic field computation coupled to factorial experiments is presented in this paper. Principles of factorial experiments are briefly reviewed and their application to design optimisation is explained. In this application experiments are replaced by magnetic field calculations. The procedure, which performs automatically all the numerical field calculations required, is described. The whole procedure is applied to a typical problem concerning permanent magnets synchronous motor with polar pieces. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 69-73] |
| Author(s): | C. Pertusa, S.Astier, Y.Lefevre, M.Lajoie-Mazenc, C. Pertusa, S.Astier, Y.Lefevre, M.Lajoie-Mazenc |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 317 KB |
| Title: | LIMITATIONS OF THE CONVENTIONAL METHODS OF FORCE AND TORQUE PREDICTION |
| Abstract: | The calculation of forces and torques developed in electromechanical devices, and their variation with changes in position or excitation, is often what the designer is, ultimately, interested in. This paper addresses some of the problems associated with the force and torque calculations based on numerical field solutions for 2-D magnetostatic problems. The problem of calculating the cogging torque characteristic of a neodymium-iron-boron permanent-magnet motor is considered and the technique of torque measurement is described briefly. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 74-79] |
| Author(s): | Antonio Flavio Licari o Nogueira, Antonio Flavio Licari o Nogueira |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 480 KB |
| Title: | COMPARISON OF CONVERGENCE RATES OF EDGE AND NODAL FINITE ELEMENTS FOR MAGNETOSTATIC PROBLEMS |
| Abstract: | Mathematical theory is used to obtain convergence estimations for magnetostatic formulations using nodal and edge elements. Numerical results of two closed boundary problems that confirm the theory are presented. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 80-83] |
| Author(s): | M. L. y Gonzalez, R. C. MesquitaM. L. y GonzalezMesquita, J. P. A. Bastos, M. L. y Gonzalez, R. C. MesquitaM. L. y GonzalezMesquita, J. P. A. Bastos |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 231 KB |
| Title: | FINITE ELEMENT SIMULATION OF AN OUT-OF-PHASE SYNCHRONIZATION OF A SYNCHRONOUS MACHINE |
| Abstract: | This paper presents the finite element simulations of the out-of-phase synchronization of a synchronous machine with an external electric system. Two cases were analysed regarding to the phase angle: 120 and 180 . Computed results are analysed and compared to analyticalvalues.[Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 84-89] |
| Author(s): | Silvio Ikuyo Nabeta, Albert Foggia, Jean-Louis Coulomb, Gilbert Reyne, Silvio Ikuyo Nabeta, Albert Foggia, Jean-Louis Coulomb, Gilbert Reyne |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 306 KB |
| Title: | A 3D FINITE-ELEMENT COMPUTATION OF STATOR END-WINDING LEAKAGE INDUCTANCE AND FORCES AT STEADY STATE OPERATING CONDITIONS IN LARGE HYDROGENERATORS |
| Abstract: | The forces acting on the stator end windings of a hydrogenerator at steady state operating conditions, as well as the end-winding leakage inductance, are calculated using a 3D finite element package. A more realistic representation for the geometry of the windings and boundaries is considered. The effects of different representations for the stator core end surface are outlined. The computed values of the inductance from time harmonic and static simulations are presented and compared with classical analytical methods. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 90-96] |
| Author(s): | Viviane Cristine Silva, Albert Foggia, Viviane Cristine Silva, Albert Foggia |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 520 KB |
| Title: | IMPROVING THE CHARGE SIMULATION METHOD FOR THE COMPUTATION OF HIGH VOLTAGE ELECTRIC FIELDS WITH EFFICIENT LEAST SQUARES TECHNIQUES |
| Abstract: | The well known Charge Simulation Method, which is commonly used for electric field calculations, is shown to be a particular and ill-conditioned case of the Least Squares Charge Simulation Method. By solving a practical problem, it is shown how to efficiently handle a least squares problem, thus obtaining results of higher precision if compared to the traditional Charge Simulation Method For the solution of the resulting linear system, several mathematical methods are analyzed and compared, being stated that the optimum combination of higher precision, lesser error propagation, lesser CPU time and lesser computer RAM are simultaneously reached when applying the Least Squares Charge Simulation Method, solved with the QR decomposition and Householder transformations. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 97-102] |
| Author(s): | J. N. Hoffmann, P. Pulino, J. N. Hoffmann, P. Pulino |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 467 KB |
| Title: | A HYBRID FINITE DIFFERENCES, AND CHARGE SIMULATION METHOD FOR THE COMPUTATION OF HIGH VOLTAGE ELECTRIC FIELDS |
| Abstract: | A new treatment is proposed to the hybrid method of Finite Differences and Charge Simulation for the computation os electric fields, entirely applicable to the similar hybrid method of Finite Element and Charge Simulation. The resulting system of linear equations is solved by using the fixed point theory, the QR decomposition and the Conjugate Gradients Squared method with a preconditioning technique. New procedures are suggested for the discretization of the boundary conditions, which lead to results with higher precision. Case studies are included. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 103-110] |
| Author(s): | J. N. Hoffmann, P. Pulino, J. N. Hoffmann, P. Pulino |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 593 KB |
| Title: | FINITE ELEMENT MODELING OF ELECTRICAL MACHINES BY SIMULTANEOUS RESOLUTION OF FIELDS AND ELECTRIC CIRCUITS EQUATIONS |
| Abstract: | In this work, we present a methodology for solving simultaneously the equations of magnetic fields and electric circuits of electrical machines. To consider the magnetic phenomena the Finite Element method is used. The machines are voltage fed and, thus, the electric circuit equations are present in the matricial system which takes into account both physical aspects. A time stepping technique is employed to simulate the steady and transient states. As result, we obtain the magnetic vector potential describing the magnetic behavior of the machine and the current established in the exciting coils. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 111-116] |
| Author(s): | N. Sadowski, R. Carlson, J. P. A. Bastos, M. Lajoie-Mazenc, N. Sadowski, R. Carlson, J. P. A. Bastos, M. Lajoie-Mazenc |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 443 KB |
| Title: | SHAPE DESIGN OPTIMIZATION OF POWER FREQUENCY ELECTROMAGNETIC DEVICES USING NUMERICAL METHODS |
| Abstract: | This paper presents the mathematical formulation concerning the solution of inverse electromagnetic problems, i.e. the shape optimization of power frequency electromagnetic devices, based on a combination of numerical methods. The optimization problem is solved using deterministic methods in which the electromagnetic field problem is treated as a subproblem of the optimization process. The field problem is calculated using the finite element (FE) method. Three deterministic approaches are studied in detail, the quadratic extended penalty method (QUA), the augmented Lagrange multiplier (ALM) method and the constrained quasi-Newton method (PLBA-CR). The work highlights the advantages and drawbacks of each approach. The search direction for the optimization is found by two distinct methods, the direct differentiation of the FE matrices and the finite difference (FD) method. In total, three problems are discussed in order to show the power and applicability of the theory presented. The PLBA-CR, when combined with the direct differentiation of the FE matrices, appears to offer important advantages over the other methods. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 117-124] |
| Author(s): | Jaime A. Ramirez, Ernest M. Freeman, C. Chat-uthai, Jo o A. Vasconcelos, Jaime A. Ramirez, Ernest M. Freeman, C. Chat-uthai, Jo o A. Vasconcelos |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 485 KB |
| Title: | DETERMINATION AND ANALYSIS OF CAUSES OF INDUCTION MOTOR MAGNETIC NOISE |
| Abstract: | This paper presents the causes of the acoustic noise magnetically generated by three-phase induction electric motors and some results of tests and calculation are discussed. The influence of the rotor slots skewing on the reduction of the magnetic noise is also analysed through calculated values. The paper gives a general view about how the magnetic noise in induction motors is generated and how much its prevision is important during the design stage. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 125-131] |
| Author(s): | Sebasti o Lauro Nau, Solon Brum Silveira, Sebasti o Lauro Nau, Solon Brum Silveira |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 459 KB |
| Title: | GROUND-3D LINKED TO LINE PARAMETERS: A METHOD TO FAULT CURRENT DISTRIBUTION AND EARTH POTENTIAL DETERMINATION |
| Abstract: | In previous work [1,2] the author presents a methodology, based on finite elements method (FEM), to calculate the potential distribution influence on the grounding area. At that time the input of the solver admits as known the split of the system. The aim of this article is to demonstrate the advantages of finite element method (FEM) associated with power systems equations with lumped parameters to intrinsically obtain the distribution of fault current in several offered conductor ways and the potential distribution on the ground, simultaneously. To solve the complex equations system, the methodology adopted was that described by Mesquita [3]. . [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 132-135] |
| Author(s): | H. O. Brodskyn, M. C. Costa, J. R.Cardoso, N. M. Abe, A. Passaro, H. O. Brodskyn, M. C. Costa, J. R.Cardoso, N. M. Abe, A. Passaro |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 307 KB |
| Title: | AN INVESTIGATION OF THE SCATTERING OF SURFACE WAVES AT DIELECTRIC SLAB WAVEGUIDE WITH AXIAL DISCONTINUITY |
| Abstract: | This paper introduces a technique for studying the radiation due to an abrupt axial discontinuity in the geometry of a planar dielectric waveguide (Slab waveguide) when an even TM surface wave strikes the discontinuity. The mode matching technique is applied at the discontinu- ity giving rise to formally exact integral equations which are solved by the Method of Moments. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 136-141] |
| Author(s): | Creso S. Da Rocha, Creso S. Da Rocha |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 394 KB |
| Title: | ADAPTIVE MESHING IN TWO-VARIABLE STATIC PROBLEMS WITH FIELD BASED ERROR ESTIMATORS USING EDGE AND FACET ELEMENTS |
| Abstract: | In this paper a family of field-based error estimators for Finite Element analysis of electrostatic and magnetostatic problems in plane and axisymmetric geometries is presented. For the error estimation in magnetostatics, each element is divided in three sub-elements using an edge element approach, whereas for electrostatic problems a subdivision using facet elements is used. The methods and the numerical techniques are described, comparisons with known solutions are performed, some examples of application in cases of practical interest are reported and the obtained results are briefly discussed. . [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 142- 147] |
| Author(s): | P. Girdinio, P. Molfino, G. Molinari, M. Nervi, P. Girdinio, P. Molfino, G. Molinari, M. Nervi |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 491 KB |
| Title: | FINITE ELEMENT MODELLING SCHEMES FOR THE DESIGN AND ANALYSIS OF ELECTRICAL MACHINES |
| Abstract: | Electrical machines are complex objects. We have found that a variety of numerical techniques are required in order to model them using finite elements. We concentrate here on the different formulations which are useful in modelling such devices. Examples of modelling some of these machines using the MEGA package are described. . [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 148- 152] |
| Author(s): | D.Rodger, P.J. Leonard, H.C. Lai, N. Allen, D.Rodger, P.J. Leonard, H.C. Lai, N. Allen |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 494 KB |
| Title: | THREE DIMENSIONAL MAGNETOSTATICS USING THE MAGNETIC VECTOR POTENTIAL WITH NODAL AND EDGE FINITE ELEMENTS |
| Abstract: | In this paper, the three dimensional vector potential magnetostatic problem is solved using nodal and edge finite elements. The influence of the gauge condition A.w=0 in the characteristics of the edge-element generated matrix is analyzed. Three gauge conditions are studied: no gauge, the complete A.w=0 gauge and the incomplete A.w=0 gauge condition. [Vol. 12, No. 1 (1997), Special Issue on International Computational Electromagnetics, pp 153-156] |
| Author(s): | E. J. Silva, R. C. Mesquita Mesquita, E. J. Silva, R. C. Mesquita Mesquita |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 261 KB |
| Title: | A NEW ITERATIVE MOMENT METHOD SOLUTION FOR CONDUCTING BODIES OF REVOLUTION |
| Abstract: | An iterative solution of the combined field integral equation (CFIE) has been obtained for perfectly conducting bodies. The proposed technique avoids the inversion of the moment method (MoM) matrix by using an iterative algorithm which shows fast convergence properties, mainly for large bodies. The algorithm is applied to several 3D problems involving bodies of revolution (BOR). Accurate currents are computed with important speedups over direct MoM solutions. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 6-10] |
| Author(s): | F. Obelleiro, J. L. Rodriguez, A. G. Pino, F. Obelleiro, J. L. Rodriguez, A. G. Pino |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 1 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 319 KB |
| Title: | CALCULATION OF THE FREQUENCY CHARACTERISTICS OF MICROSTRIPS DISCONTINUITIES ON NON-DIAGONAL ANISOTROPIC SUBSTRATES USING FDTD |
| Abstract: | This paper describes modifications of the conventional finite-difference time-domain (FDTD) method to the full-wave analysis of frequency dependent characteristics of microstrips discontinuities on non-diagonal anisotropic substrates. The application of the conventional FDTD is limited to materials with diagonal-anisotropic material matrices. In this paper it is shown that this restriction can be removed: First, steps for obtaining the FDTD equations for the analysis of microstrips discontinuities on substrates with fully anisotropic permittivity matrices are derived. Then, using the Fourier transform of the computed results in the time-domain, the scattering parameters as functions of the frequency are calculated for several examples. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 11-15] |
| Author(s): | S. M. Chehrehrazi, A. R. Baghai-Wadji, S. M. Chehrehrazi, A. R. Baghai-Wadji |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 351 KB |
| Title: | ELECTROMAGNETIC WAVES IN A NONLINEAR DISPERSIVE SLAB |
| Abstract: | The electromagnetic scattering of a normal incident plane wave from a strongly nonlinear and dispersive dielectric slab is considered. The dynamics of the polarization density vector are described through a forced nonlinear ordinary differential equation of Duffing type, which takes both dispersive and nonlinear effects into account. The aim of the paper is to study the behaviour of the electromagnetic fields by using the Galerkin method. In particular it is shown that shock waves with infinite slope cannot be developed in real media because of the dispersion . [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering pp 16-19] |
| Author(s): | G. Miano, C. Serpico, L. Verolino, G. Panariello, G. Miano, C. Serpico, L. Verolino, G. Panariello |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 281 KB |
| Title: | SENSITIVITY ANALYSIS USING HIGH ORDER DERIVATIVES |
| Abstract: | In this article, we present a method of sensitivity analysis based on high order derivatives and Taylor expansion. The principle is to find a polynomial approximation of the finite element solution in terms of the sensitivity parameters. We present this method on two dimensional linear magnetostatic and linear magnetodynamic problems. The sensitivity parameters can be either physical parameters or geometric ones. Once the high order derivatives are found, the Taylor expansion allows evaluations for a new set of parameters. The time needed to obtain a new solution is negligible compared to a standard finite element re-analysis. This implies a dramatic change in the use of computational tools. Moreover, the availability of fast evaluations allows a wide use of optimization algorithms. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 20-25] |
| Author(s): | J. L. Coulomb, P. Petin, L. Saludjian, N. Nguyen Thanh, R. Pacaut, J. L. Coulomb, P. Petin, L. Saludjian, N. Nguyen Thanh, R. Pacaut |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 499 KB |
| Title: | SELF ADAPTIVE FUZZY SETS IN MULTI OBJECTIVE OPTIMIZATION USING GENETIC ALGORITHMS |
| Abstract: | Optimization in electrical engineering has attracted an increasing attention over the last few years. Various strategies to solve electromagnetic optimization problems have been introduced, amongst them stochastic, deterministic and hybrid ones. Most of today's real world applications, however, involve multiple conflicting objectives which should be considered simultaneously. The aim of this paper is to introduce self adaptive fuzzy sets to treat vector optimization problems. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 26-31] |
| Author(s): | Ch. Magele, G. Furntratt, B. Brandstatter, K.R. Richter, Ch. Magele, G. Furntratt, B. Brandstatter, K.R. Richter |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 428 KB |
| Title: | OPTIMISATION OF THE SHAPE OF THE FERROMAGNETIC CORE OF FLUXSET TYPE MAGNETIC FIELD SENSORS |
| Abstract: | A method is presented for the optimisation of the shape of the ferromagnetic core of fluxset type magnetic filed sensors. The objective of the optimisation is to find a core shape that guarantees the most homogeneous magnetisation of the core due to a given external magnetic field. By finding the optimal shape of the core the sensitivity of the sensor is improved. Since the thickness of the ferromagnetic conducting ribbon core used for fluxset sensors is considerably smaller than its other dimensions, the presence of the core is modelled by magnetic and conducting surface currents flowing in a mathematical surface representing the core. The electromagnetic field is calculated by solving an integral equation derived from the assumption of impedance type boundary conditions on the two sides of this surface. The core shape is optimised by minimising the magnetisation differences at different locations of the core. Simulated annealing procedure is used for the optimisation. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 32-37] |
| Author(s): | Jozsef Pavo, Jozsef Pavo |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 671 KB |
| Title: | NUMERICAL TECHNIQUES FOR THE INVERSION OF EDDY CURRENT TESTING DATA |
| Abstract: | In this paper, we discuss two techniques for the reconstruction of conductivity profiles in the low frequency limit. The first one is based on the second order approximation of the scattered field operator. In the second procedure, the problem is linearized at the expense of an increase in the number of unknowns including, in this case, the current density and the electric field. Some simple 2D examples are presented to point out and compare the main features of the two approaches. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 38-43] |
| Author(s): | Guglielmo Rubinacci, Antonello Tamburrino, Guglielmo Rubinacci, Antonello Tamburrino |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 573 KB |
| Title: | MAGNETIC MATERIAL PROPERTY IDENTIFICATION USING NEURAL NETWORKS |
| Abstract: | In the numerical solution of field problems for many devices, the modeling of the hysteresis properties of a material is extremely important. While considerable work has been published on models for handling this behavior, it is still difficult to obtain the parameters for these models from measured data. This paper proposes the use a neural network for this operation. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 44-49] |
| Author(s): | Hamadou H. Saliah, David A. Lowther, Hamadou H. Saliah, David A. Lowther |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 561 KB |
| Title: | OPTIMIZATION OF A SMES DEVICE UNDER NONLINEAR CONSTRAINTS |
| Abstract: | In this paper a method to calculate the gradients for the TEAM 22 problem is presented. Furthermore an objective function different from the one proposed in the benchmark is used where the energy requirement was handled as an equality constraint. The so derived gradients of the objective function and the constraints together with a standard optimization routine are used to solve the problem. In the last section some new results concerning the presence of local minima for the problem are given. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 50-53] |
| Author(s): | B. R. Brandstatter, Wolfgang Ring, B. R. Brandstatter, Wolfgang Ring |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 383 KB |
| Title: | RECONSTRUCTION OF INHOMOGENEOUS LOSSY DIELECTRIC OBJECTS IN ONE DIMENSION |
| Abstract: | The 1D inverse scattering problem of reconstructing the material properties of an inhomogeneous lossy dielectric slab is considered. The material properties are reconstructed using scattering data from time harmonic electromagnetic plane waves. The incident plane waves are either TE or TM polarized. The inverse scattering problem formulated as a nonlinear optimization problem by means of integral equations is numerically solved using an iterative scheme and Tikhonov regularization. Numerical examples with both types of polarization are presented. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 54-59] |
| Author(s): | W. Rieger, M. Haas, C. Huber, G. Lehner, W.M. Rucker, W. Rieger, M. Haas, C. Huber, G. Lehner, W.M. Rucker |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 506 KB |
| Title: | LAGRANGIAN BEM-FEM SOLUTION OF ELECTROMAGNETIC-MECHANICAL COUPLED PROBLEMS |
| Abstract: | In the framework of the electro-mechanical coupled problems, the coupling between the magnetic diffusion and the elastic deformation equations is treated numerically. A mixed BEM-FEM approach for the electromagnetic part, and a FEM approach for the mechanical part, are proposed. Advantages are taken from a Lagrangian formulation of the problem. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 60-65] |
| Author(s): | A. Formisano, R. Martone, F. Villone, A. Formisano, R. Martone, F. Villone |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 436 KB |
| Title: | MODELLING OF DEGAUSSING COILS EFFECTS ON SHIPS |
| Abstract: | This paper presents our work on magnetic modelling of ships, especially their degaussing coils. We first focus on these coils effects in the FEM computations. The main reason of bad results is a locally inadequate mesh. We propose a method named " reduced potential jump" to avoid the use of a very fine mesh. Then, comparison of results is presented for a simple geometry. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 66-70] |
| Author(s): | F. Le Dorze, J. P. Bongiraud, J. L. Coulomb, G. Meunier, X. Brunotte, F. Le Dorze, J. P. Bongiraud, J. L. Coulomb, G. Meunier, X. Brunotte |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 302 KB |
| Title: | A THREE-DIMENSIONAL ANALYSIS OF MAGNETIC SHIELDING WITH THIN LAYERS |
| Abstract: | This paper describes a numerical method for the analysis of the magnetic shielding with thin layers in three dimensional, time-harmonic magnetic fields. In this method, FEM is employed to solve a couple of differential equations which express the surface impedance of the thin shielding materials. The magnetic fields in air regions are modeled by means of BEM. The above formulations are coupled to evaluate the shielding properties. The resultant matrix equation includes unknowns of two times the number of nodal points. This method can analyze not only a shielding system with closed surfaces but also that with open surfaces without |
| Author(s): | H. Igarashi, T. Honma, A. Kost, H. Igarashi, T. Honma, A. Kost |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 288 KB |
| Title: | A C.A.E. TOOL TO UNDERSTAND MAGNETOSTATICS |
| Abstract: | We present in this paper a Computer Aided Education package allowing to visualize the magnetostatic field in and around the magnetic circuit of a double-U shaped contactor. The modeling of this device is performed by solving in real time a non-linear finite element problem. The imple- mentation of this method is optimized greatly in order to allow to animate field patterns in real time in reaction to any user interaction. An evaluation of the improvements brought by this technique to the learning capabilities of students is presented. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 81-84] |
| Author(s): | F. Buret, D. Muller, A. Nicolas, L. Nicolas, F. Buret, D. Muller, A. Nicolas, L. Nicolas |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 414 KB |
| Title: | NUMERICAL MODELLING OF AN AXIAL-FIELD SOLID DISK INDUCTION MACHINE |
| Abstract: | In this paper a method for the steady-state analysis of an axial-field induction motor with a solid disk rotor is proposed. The boundary condition for the axial component of the magnetic flux density has been calculated by means of an analytical procedure. Accordingly the simulation region is restricted to the air-gap and the rotor. Then the axial component of the diffusion equation is solved for by using a finite difference scheme. Subsequently the azimuthal component of the magnetic flux density and the current density induced in the rotor come out from the field's laws. The validity of the proposed method has been tested by comparing the numerical results with data measured on a double-stator prototype. Finally the numerical procedure has been used for the analysis of the performance of a motor for light vehicle propulsion and the results of the simulation are shown. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 85- 89] |
| Author(s): | Marco Angeli, Nunzio Esposito, Antonino Musolino, Bernardo Tellini, Marco Angeli, Nunzio Esposito, Antonino Musolino, Bernardo Tellini |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 340 KB |
| Title: | MODELLING DYNAMIC HYSTERESIS IN FERROMAGNETIC SHEETS UNDER TIME-PERIODIC SUPPLY CONDITIONS |
| Abstract: | This paper presents an application of the Dynamic Preisach Model as proposed by Bertotti, to the analysis of electromagnetic phenomena inside a ferromagnetic lamination subject to imposed time-periodic magnetic flux. The field problem, considered as one dimensional, is formulated in terms of magnetic field and the Fixed Point technique is used for the treatment of the hysteretic nonlinearity. The solution is carried out in the harmonic domain by means of the Finite Element method. The original implementation of the Dynamic Preisach Model is detailed and comparisons with measurements are presented in the case of sinusoidal excitations. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 90-95] |
| Author(s): | Oriano Bottauscio, Mario Chiampi, Maurizio Repetto, Oriano Bottauscio, Mario Chiampi, Maurizio Repetto |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 463 KB |
| Title: | DYNAMIC OPERATION OF COILS WITH FERROMAGNETIC CORES TAKING MAGNETIC HYSTERESIS INTO ACCOUNT |
| Abstract: | The computation of electromagnetic field diffusion in ferromagnetic and conductive media is coupled to circuit analysis problems, involving coils with iron cores. The classical Preisach model provides the relationship between magnetic field intensity and flux density at the local level, inside the core. Combined with a 2D eddy current simulation, carried out by a time stepping method, the dynamic operation of the core is modelled. The circuit equations are solved taking the effects of hysteresis and skin effects caused by eddy currents induced in core sheets into account. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 96-101] |
| Author(s): | Janos Fuzi, Janos Fuzi |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 433 KB |
| Title: | A STRONG COUPLING MODEL FOR THE SIMULATION OF MAGNETOMECHANICAL SYSTEMS USING A PREDICTOR/MULTI-CORRECTOR ALGORITHM |
| Abstract: | A recently developed modeling scheme for the numerical simulation of coupled magnetomechanical systems is presented. The scheme allows the calculation of dynamic rigid motions as well as deformations of magnetic and anti-magnetic materials in a magnetic field. The equations governing the magnetic and mechanical field quantities are solved using a combined Finite Element /Boundary-Element-Method (FEM-BEM). To circumvent the nonlinear system of equations resulting from a direct coupling of the magnetic and mechanical systems, the calculation of the magnetic forces is based on predictor values of the magnetic quantities. Therewith, a decoupling into a magnetic and mechanical matrix equation can be achieved. To ensure the strong coupling between the magnetic and mechanical quantities, a sophisticated Predictor/Multicorrector Algorithm is used resulting in an efficient iteration between the two matrix equations within a single time step. Computer simulations of an electromagnetic forming system and a magnetomechanical transducer immersed in an acoustic fluid (acoustic power source) show good agreement between simulation results and measured data. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 102-106] |
| Author(s): | M. Kaltenbacher, H. Landes, R. Lerch, M. Kaltenbacher, H. Landes, R. Lerch |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 347 KB |
| Title: | RESULTS OF PARALLELISATION OF EXISTING ELECTROMAGNETIC FINITE ELEMENT CODES ON SOME DIFFERENT PARALLEL ARCHITECTURES |
| Abstract: | In this paper the results obtained from the parallelisation of some 3D industrial electromagnetic Finite Element codes within the ESPRIT Europort 2 project PARTEL are presented. The basic guidelines for the parallelisation procedure, based on the Bulk Synchronous Parallel approach, are presented and the encouraging results obtained in terms of speed-up on some selected test cases of practical design significance are outlined and discussed. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 107-112] |
| Author(s): | M. Dracopoulos, K. Palrot, G. Molinari, M. Nervi, J. Simkin, M. Dracopoulos, K. Palrot, G. Molinari, M. Nervi, J. Simkin |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 617 KB |
| Title: | THE NEWTON-RAPHSON METHOD FOR COMPLEX EQUATION SYSTEMS |
| Abstract: | A formulation for the complex Newton-Raphson method is proposed. The derivation is obtained on the assumption of a non-analytical system. The method is applied to the finite element calculation of shielding problems with sinusoidal ex-citation and ferromagnetic material. An application example for which measurement data are available is given in order to judge the convergence characteristics and the reliability of the proposed method. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 113-116] |
| Author(s): | Dieter Lederer, Hajime Igarashi, Arnulf Kost, Dieter Lederer, Hajime Igarashi, Arnulf Kost |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 319 KB |
| Title: | SOME ASPECTS OF MAGNETIC FORCE COMPUTATION USING BEM-FEM COUPLING |
| Abstract: | For the calculation of magnetic forces with the Maxwell stress tensor the normal and the tangential derivatives of the vector potential A have to be known. We choose Co-continuous elements, therefore A and its tangential derivatives are continuous. In contrast, the normal derivative A/ n calculated with the finite element method is continuous only in a weak sense. When BEM-FEM coupling is used however, the value of A/ n is uniquely available on the coupling surfaces from the BEM formulation. Two methods of magnetic force computation using A/ n either from FEM or from BEM data will be presented. Their accuracy will be compared by means of several examples. [Vol. 12, No. 2 (1997), pp Special Issue on Numerical Field Calculations in Electrical Engineering, 117-120] |
| Author(s): | Joachim Fetzer, Stefan Kurz, Gunther Lehner, Wolfgang M. Rucker, Joachim Fetzer, Stefan Kurz, Gunther Lehner, Wolfgang M. Rucker |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 270 KB |
| Title: | THE NUMERICAL TREATMENT OF SINGULAR INTEGRALS IN BOUNDARY ELEMENT CALCULATIONS |
| Abstract: | In this paper a general method for the evaluation of singular boundary element integrals over three-dimensional isoparametric boundary elements of higher order is presented. This method permits an efficient integration of strongly singular kernels of order O(1/r2) and of nearly strong singular kernels on curved surfaces. For numerical examples the proposed integration scheme is compared with analytical test examples showing high efficiency and accuracy. This new method has full generality and, therefore, can be applied in any field of electromagnetics. The actual computation can be easily included in any existing computer code, e. g. for the solution of electromagnetic scattering problems. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 121-126] |
| Author(s): | C.J. Huber, W. Rieger. M. Haas, W.M. Rucker, C.J. Huber, W. Rieger. M. Haas, W.M. Rucker |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 416 KB |
| Title: | MODELLING EDDY CURRENTS INDUCED BY ROTATING SYSTEMS |
| Abstract: | As part of a Japanese funded project, a transient eddy current code is being extended to allow for rotational systems. By allowing the system to rotate, induced eddy currents must be modelled. The system being developed uses the "lock-step" approach to model the rotation. As other facilities are included (non-linear materials for example), the solution time of the final code becomes sufficiently large that special care must be taken, and investigations into using parallel hardware becomes necessary. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 131-134] |
| Author(s): | C. R. I. Emson, C. P. Riley, D. A. Walsh, C. R. I. Emson, C. P. Riley, D. A. Walsh |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 412 KB |
| Title: | BEM-FEM COUPLING IN ELECTROMECHANICS: A 2-D WATCH STEPPING MOTOR DRIVEN BY A THIN WIRE COIL |
| Abstract: | This paper deals with the transient numerical analysis of 2-d electromechanical devices driven by thin wire coils. Their dynamical behavior is described by the Maxwell equations, by the constitutive relations, and by the equations of motion. For the solution of the electromagnetic problem the BEM-FEM coupling method is used. A two- dimensional watch stepping motor is presented as an example. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 135-139] |
| Author(s): | Stefan Kurz, Joachim Fetzer, Thomas Kube, Gunther Lehner, Wolfgang M. Rucker, Stefan Kurz, Joachim Fetzer, Thomas Kube, Gunther Lehner, Wolfgang M. Rucker |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 389 KB |
| Title: | HYBRID FORMULATIONS FOR 3D MAGNETOSTATIC AND EDDY CURRENT PROBLEMS |
| Abstract: | Hybrid formulations for solving nonlinear 3D magnetostatic and eddy current problems in terms of magnetic field H are presented. In the pro- posed formulations integral operators are utilized as if the boundary conditions for a partial differential equation were solved within the system of equations. A good correspondence between the results of the presented methods and measurements or other methods is obtained for some test problems. [Vol. 12, No. 2 (1997), Special Issue on Numerical Field Calculations in Electrical Engineering, pp 140-144] |
| Author(s): | Kimmo Forsman, Lauri Kettunen, Kimmo Forsman, Lauri Kettunen |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 2 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 470 KB |
| Title: | DOMAIN DECOMPOSITION STRATEGIES FOR SOLVING THE MAXWELL EQUATIONS ON DISTRIBUTED PARALLEL ARCHITECTURES |
| Abstract: | Domain decomposition strategies for solving hyperbolic systems of partial differential equations on distributed-memory parallel computing platforms are investigated. The logically-rectangular computational domain is divided either one, two, or three dimensionally into a series of computational blocks, and each block is assigned to a single processor. Theoretical predictions using standard parallel performance models indicate that higher-dimensional decompositions provide superior parallel program performance in terms of scalability. The theory is tested using a finite-volume time-domain (FVTD) Maxwell equations solver to compute the electromagnetic fields inside a rectangular waveguide using various grid sizes and processor numbers on three different parallel architectures- the Intel Paragon, the IBM SP2, and the Cray T3D. The specific performance of the FVTD algorithm on the three machines is investigated, the relation between processor connection topology and message passing performance of a typical grid-based hyperbolic equation solver are identified, and the results are used to augment the classical parallel performance model. Although clear performance trends emerge in terms of the dimensionality of the decomposition, results indicate that higher-dimensional decompositions do not always provide superior parallel performance. [Vol. 12, No. 3 (1997), pp 4-15] |
| Author(s): | Douglas C. Blake, Thomas A. Buter, Douglas C. Blake, Thomas A. Buter |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 3 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 892 KB |
| Title: | MOMENT METHOD SURFACE PATCH AND WIRE GRID ACCURACY IN THE COMPUTATION OF NEAR FIELDS |
| Abstract: | The accuracy of surface patch and wire grid moment method models for the of near fields is investigated. A sphere and a flat plate with plane wave illumination are examined. It is found that wire grids exhibit stronger near field anomalies than surface patches, which have the current more distributed over the surface. Nevertheless, good results can be obtained with a wire grid, provided that a small distance from the wire grid surface is maintained The surface patch results are obtained using the Junction code. Wire grid results are with both the MBC and NEC codes. Validation the sphere is by comparison with an exact solution obtained from the NECBSC code. [Vol. 12, No. 3 (1997), pp 16-25] |
| Author(s): | Robert Paknys, Leslie R. Raschkowan, Robert Paknys, Leslie R. Raschkowan |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 3 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 578 KB |
| Title: | USING THE FDTD METHOD TO MODEL THE REFLECTION COEFFICIENT OF A VIVALDI TAPERED SLOT ANTENNA FED THROUGH A PLANAR BALUN |
| Abstract: | In this paper, the Time-Domain (FDTD) method was used to determine the reflection coefficient vs. frequency of a Vivaldi Tapered Dual-Slot Antenna fed through a planar balun. The reflection coefficient at the input port of the feed stripline was determined through the separate computation of the reflection coefficient of representation of the antenna section and the scattering matrix of the balun, assuming that the electromagnetic coupling between these sections was negligible. Experimental results, which were obtained on a prototype of this structure, confirmed the validity of the proposed approach and demonstrate that the coupling of the model. [Vol. 12, No. 3 (1997), pp 26-30] |
| Author(s): | G. Biffi Gentili, R Braccini, M. Leoncini, G. Biffi Gentili, R Braccini, M. Leoncini |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 3 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 308 KB |
| Title: | FINITE-DIFFERENCE TIME-DOMAIN MODELING OF LIGHT-TRAPPING IN SOLAR CELLS |
| Abstract: | To maximize light-trapping, the absorption of light in the solar cell is maximized. The ways to increase light-trapping are to texture the surfaces of the solar cell and to use anti-reflection coatings. The power spectrum of sunlight also plays an important role in light-trapping. In general, a solar cell consists of multiple layers of dielectric materials. Each dielectric has a complicated surface texture geometry to increase light-trapping. This paper concentrates on solving Maxwell's equations for the general solar cell configuration under illumination from the sun. The absorption and maximum achievable current density are calculated and used to quantify light-trapping in a given solar cell design. Thin solar cells promise to yield higher current collection than thick solar cells at a lower cost [1]. Low cost solar cells are usually characterized by short diffusion length semiconductors. Most minority carriers created within the distance equal to the diffusion length contribute to the electrical current of a solar cell. Hence, the solar cell must be thin when low quality materials are used. As solar cells decrease in size, the ray-trace model becomes inaccurate as previously demonstrated in [2]. A full-wave Finite-Difference Time-Domain (FDTD) light-trapping model is demonstrated to accurately study light-trapping of thin-film solar cells. [Vol. 12, No. 3 (1997), pp 31-42] |
| Author(s): | Todd Marshall, Melinda Piket-May, Todd Marshall, Melinda Piket-May |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 3 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 872 KB |
| Title: | MODELLING EDDY CURRENTS IN UNBOUNDED STRUCTURES USING THE IMPEDANCE METHOD |
| Abstract: | In this paper extensions to the impedance network method are presented. In particular the method has been applied to problems with boundaries extending to infinity. The infinite boundary condition can also be applied to lines of symmetry in the given geometry. Two dimensional surface models have been verified by comparison of numerical and experimental results in which the potential was measured along the edge of copper sheeting of various shapes located in a uniform, quasi-static magnetic field. The method has potential for modelling three dimensional structures including anisotropic earth planes, arbitrarily shaped buried objects, and both finite and infinitely long faults, dykes, pipes, cylinders and cracks. [Vol. 12, No. 3 (1997), pp 43-49] |
| Author(s): | Daniel James Daniel James, David V. Thiel, Daniel James Daniel James, David V. Thiel |
| File Type: | Journal Paper |
| Issue: | Volume: 12 Number: 3 Year: 1997 |
| Download Link: | Click here to download PDF File Size: 479 KB |
| Title: | CALCULATION OF ELECTROMAGNETIC SCATTERING VIA VARIATIONS AND ANALYTIC CONTINUATION |
| Abstract: | In this paper we review a numerical method we introduced recently for the solution of problems of electromagnetic scattering. Based on variations of the boundaries of the scatterers and analytic continuation, our approach yields algorithms which are applicable to a wide variety of scattering configurations. We discuss some recent applications of this method to scattering by diffraction gratings and by large two-dimensional bounded bodies, and we present results of new applications to three-dimensional gratings containing corners and edges. In many cases of practical interest our algorithms give nu- merical results which are several orders of magnitude more accurate than those given by classical methods. [Vol. 11, No. 1 (1996), pp 17- 31, Special issue on Applied Mathematics: Meeting the challenges presented by computational electromagnetics] |
| Author(s): | Oscar P. Bruno, Fernando Reitich, Oscar P. Bruno, Fernando Reitich |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 1 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 1314 KB |
| Title: | ERROR CONTROL IN NUMERICAL SOLUTIONS OF BOUNDARY INTEGRAL EQUATIONS |
| Abstract: | A method of estimating the error committed in numerical solutions of integral equations is presented. It is shown how the error can be computed in spaces other than L^2, why this is reasonable and sometimes necessary. The appropriate function spaces are also shown to lead to bounded condition numbers even for first kind equations. [Vol. 11, No. 1 (1996), pp 32-36, Special issue on Applied Mathematics: Meeting the challenges presented by computational electromagnetics] |
| Author(s): | G . C . HSIAO, R. E . R. E . KLEINMAN, G . C . HSIAO, R. E . R. E . KLEINMAN |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 1 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 386 KB |
| Title: | CALCULATIONS IN MATHEMATICA ON LOW-FREQUENCY DIFFRACTION BY A CIRCULAR DISK |
| Abstract: | This paper is devoted to the symbolic calculation of the scattering coefficient in diffraction by a circular disk, by the use of Mathematica. Three diffraction problems are considered: scalar diffraction by an acoustically soft disk, scalar diffraction by an acoustically hard disk, and electromagnetic diffraction by a perfectly conducting disk. In the low-frequency approximation, the solutions of these problems are in the form of expansions in powers of ka, where a is the radius of the disk and k is the wave number. The emphasis is on the low-frequency expansion for the scattering coefficient, of which several terms are determined exactly with the help of Mathematica. [Vol. 11, No. 1 (1996), pp 47-56, Special issue on Applied Mathematics: Meeting the challenges presented by computational electromagnetics] |
| Author(s): | J. Boersma, M. J. H. Anthonissen, J. Boersma, M. J. H. Anthonissen |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 1 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 597 KB |
| Title: | SCATTERING BY LARGE STRUCTURES WITH PERIODIC SURFACES: A PROTOTYPE PROBLEM |
| Abstract: | A hybrid method which uses both numerical and asymptotic techniques is described and applied to the scattering of an electromagnetic wave off a large corrugated circular cylinder. The radius of the cylinder is large compared to the wavelength of the incident radiation, but the corrugation height and period are of the same order as the wavelength. This problem is a prototype of a more general situation where the surface of a target is covered with a periodic coating. The method of attack essentially blends boundary layer theory, which describes the local scattering behavior of the surface, and the theory of geometrical optics which gives a global description of the scattering. Although the hybrid method is only developed here for this simple model, its applicability for other targets is clear. [Vol. 11, No. 1 (1996), pp 57-62, Special issue on Applied Mathematics: Meeting the challenges presented by computational electromagnetics] |
| Author(s): | G.A. Kriegsmann, G.A. Kriegsmann |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 1 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 428 KB |
| Title: | MONO-STATIC RCS COMPUTATION WITH A BLOCK GMRES ITERATIVE SOLVER |
| Abstract: | We present a new method of computing mono-static radar cross sections using a preconditioned Block GMRES iterative algorithm. The convergence properties of this algorithm are analyzed using RCS error, equation residual error and solution error. It is found that this method is nearly an order of magnitude faster than direct methods (LINPACK) for realistic method of moment problems. [Vol. 11, No. 1 (1996), pp 63-69, Special issue on Applied Mathematics: Meeting the challenges presented by computational electromagnetics] |
| Author(s): | William E. Boyse, Andrew A. Seidl, William E. Boyse, Andrew A. Seidl |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 1 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 617 KB |
| Title: | MODERN KRYLOV SUBSPACE METHODS IN ELECTROMAGNETIC FIELD COMPUTATION USING THE FINITE INTEGRATION THEORY |
| Abstract: | A theoretical basis for numerical electromagnetics, the so-called Finite Integration Theory, is described. Based upon Maxwell's equations in their integral form, it results in a set of matrix equations, each of which is a discrete analogue of its original analytical equation. Applications of this discretization process are described here in the context of the numerical simulation of electroquasistatic problems and of time-harmonic field computations including a new type of waveguide boundary condition, which is presented here for the first time. In both fields the process of mathematical modelling and discretization yields large systems of complex linear equations which have to be solved numerically. For this task several modern Krylov subspace methods are presented such as BiCG, CGS and their more recent stabilized variants CGS2, BiCGSTAB(I) and TFQMR. They are applied in connection with efficient preconditioning methods. The applicability of these modern methods is shown for a number of examples for both problem types. [Vol. 11, No. 1 (1996), pp 70-84, Special issue on Applied Mathematics: Meeting the challenges presented by computational electromagnetics] |
| Author(s): | Markus Clemens, Rolf Schuhmann, Ursula van Rienen, Thomas Weiland, Markus Clemens, Rolf Schuhmann, Ursula van Rienen, Thomas Weiland |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 1 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 1195 KB |
| Title: | FINITE DIFFERENCE METHODS FOR THE NONLINEAR EQUATIONS OF PERTURBED GEOMETRICAL OPTICS |
| Abstract: | Finite difference methods are developed to solve the nonlinear partial differential equations approximating solutions of the Helmholtz equation in high frequency regime. Numerical methods are developed for solving the geometrical optics approximation, the classical asymptotic expansion, and a new perturbed geometrical optics system. We propose a perturbed geometrical optics system to recover diffraction phenomena that are lost in geometrical optics approximations. We discuss techniques we have developed for recovering multivalued solutions and we present numerical examples computed with finite difference approximations of the above systems. [Vol. 11, No. 1 (1996), pp 90-98, Special issue on Applied Mathematics: Meeting the challenges presented by computational electromagnetics] |
| Author(s): | E. Fatemi, B. Engquist, and S. Osher, E. Fatemi, B. Engquist, and S. Osher |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 1 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 661 KB |
| Title: | ANALYSIS OF THE FINITE ELEMENT RADIATION MODEL CODE FOR ANTENNA MODELING |
| Abstract: | The Finite Element Radiation Model (FERM) code is applied to examine radiation patterns and input impedance of various antenna con- figurations on complex helicopters. This paper addresses the strengths and weaknesses of the FERM code when applied in antenna analysis and is compared with other national codes, such as the Numerical Electromagnetics Code (NEC). In addition, guidelines are outlined for various applications of the code. [Vol. 11, No. 2 (1996), pp 4-13] |
| Author(s): | Marcos C. Medina, Constantine A. Balanis, Jian Peng, Panayiotis A. Tirkc Panayiotis A. Tirkc, Marcos C. Medina, Constantine A. Balanis, Jian Peng, Panayiotis A. Tirkc Panayiotis A. Tirkc |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 2 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 702 KB |
| Title: | ACCURACY OF THE FINITE ELEMENT METHOD WITH SECOND ORDER ABSORBING BOUNDARY CONDITIONS FOR THE SOLUTION OF APERTURE RADIATION PROBLEM |
| Abstract: | The Finite Element Method with second order Absorbing Boundary Condition is a recently developed computational technique that finds use in antenna design and Electromagnetic Compatibility simulation. To determine the accuracy of this new procedure, the problem of aperture radiation was studied. The near zone and aperture fields of a waveguide antenna computed using the Finite Element Method are compared with published data and results found using other simulation techniques. These comparisons show that the new method is accurate even when the ABC boundary conforms to the problem geometry and is placed as near as /2pi to the aperture. [Vol. 11, No. 2 (1996), pp 14-23] |
| Author(s): | John Silvestro, Xingchao Yuan, Zoltan Cendes, John Silvestro, Xingchao Yuan, Zoltan Cendes |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 2 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 580 KB |
| Title: | A MOMENT METHOD FORMULATION FOR THE ANALYSIS OF WIRE ANTENNAS ATTACHED TO ARBITRARY CONDUCTING BODIES DEFINED BY PARAMETRlC SURFACE |
| Abstract: | A Moment Method (MM) technique for the analysis of wire antennas on board resonant-sized bodies modelled with parametric surfaces is presented. The approach may have useful applications for the study of the behaviour of wire antennas on board complex conducting structures like aircrafts. The current is represented by curved rooftop functions on the body, piecewise linear functions on the wires and a new junction function in the attachment region between the body and the antenna. The bodies are precisely defined by means of a small number of NURBS surfaces (Non Uniform Rational B-Splines) and Bezier patches (BP). In addition the new junction function that can be defined over any BP allows the antenna to be attached to any part of the body. Radiation patterns and input impedance calculations for several geometries are presented to show the accuracy of the method. The results are successfully validated when comparisons with measurements or results from other methods are carried out. [Vol. 11, No. 2 (1996), pp 32-39 |
| Author(s): | F. Rivas, L. Valle, M.F. Catedra, F. Rivas, L. Valle, M.F. Catedra |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 2 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 534 KB |
| Title: | A POSTERIORI ERROR ESTIMATES FOR TWO-DIMENSIONAL ELECTROMAGNETIC FIELD COMPUTATIONS: BOUNDARY ELEMENTS AND FINITE ELEMENTS |
| Abstract: | A brief summary of the variational boundary-value problem formulation of the 2D finite element/boundary element (FE/BE) method is presented. >From this a posteriori error estimates and error indicators for the FE/BE method are developed and applied to electromagnetic scattering and radiation problems. The results obtained indicate that these error estimates and indicators can be obtained within negligible computational times and can be used successfully to obtain valuable a posteriori accuracy and convergence information regarding the reliability of the FE/BE method solutions. [Vol. 11, No. 2 (1996), pp 40-54] |
| Author(s): | F.J.C. Meyer, D.B. Davidson, F.J.C. Meyer, D.B. Davidson |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 2 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 1233 KB |
| Title: | MODELLING OF AN ARBITRARILY-ORIENTED MOBILE TELEPHONE HANDSET IN THE FINITE-DIFFERENCE TIME-DOMAIN FIELD COMPUTATION METHOD |
| Abstract: | The implementation of a generic mobile telephone handset model in the Finite Difference Time Domain (FDTD) method for computation of electromagnetic field distributions is described. The handset can be rotated about the principal FDTD axes to achieve any orientation. The 'thin wire' technique is used to model the antenna in a way that ensures that its correct electrical length is maintained despite the 'staircasing' effect of the FDTD grid. Computed predictions from the model agree with near-field measurements on a physical realisation of the handset, and accurate near and far fields are calculated for arbitrary orientations of the handset. It is concluded that this wire rotation technique has broad application to problems involving components that are required to move in relation to fixed structures. [Vol. 11, No. 2 (1996), pp 55-65] |
| Author(s): | P.S. Excell, P. Olley, N.N. Jackson, P.S. Excell, P. Olley, N.N. Jackson |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 2 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 886 KB |
| Title: | A MAGNETIC FIELD ITERATIVE TECHNIQUE FOR IMPROVING HIGH FREQUENCY PREDICTION METHODS |
| Abstract: | A Magnetic Field Iterative Technique (MFIT) is developed as a technique for improving the results from high frequency based prediction methods. The technique combines the accuracy of low frequency methods with the speed of high frequency methods to develop a contraction mapping based, iterative solver, which is directly parallelizable on current massively parallel processing machines. In this paper, the MFIT is developed from a Magnetic Field Integral Equation (MFIE) and its contraction discussed. Results obtained mapping properties are using the technique and convergence properties are three dimensional perfect illustrations of the technique's presented for both two and electrically conducting (PEC) targets. [Vol. 11, No. 2 (1996), pp 66-71] |
| Author(s): | Daniel D. Reuster, Gary A. Thiele, Paul W. Eloe, Daniel D. Reuster, Gary A. Thiele, Paul W. Eloe |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 2 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 1171 KB |
| Title: | MODELING OF REMOTE FIELD EDDY CURRENT TRANSIENT PHENOMENA |
| Abstract: | An integral formulation is presented and used for the analysis of the Remote Field Eddy Current (RFEC) transient phenomena. The model presented allows simple and accurate modeling of RFEC systems in the presence of axisymmetric defects. The method has been validated first by comparison of the computed results with results obtained with an analytical model. Then the method was used to show that the Remote Field effect is mainly due to a direct induction effect rather than propagation effects. The Remote Field effect phenomena are usually analysed using a steady state domain. However, the results obtained here have shown that detection of defects is not due to a steady state phenomenon, but depends mainly on the transient signal. [Vol. 11, No. 2 (1996), pp 72- 75] |
| Author(s): | M. Raugi, N. Ida, M. Raugi, N. Ida |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 2 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 297 KB |
| Title: | SOLUTION OF LAPLACE'S EQUATION USING MULTIPLE PATHS METHOD (MPM) |
| Abstract: | A probabilistic method called the multiple paths method (MPM) is presented to solve the potential equation. Unlike other probabilistic techniques there is no need for the generation of a grid resulting in less computation time and simplicity. The method is based on the calculation of the probability of absorption of a particle at a point on the boundary. The random walk is along a "path" which is a line passing through the starting point, where the potential is to be determined. The results show good agreement with other probabilistic methods and numerical techniques. [Vol. 11, No. 3 (1996), pp 4-8 |
| Author(s): | J. Rashed-Mohasselel, M. Fasih, J. Rashed-Mohasselel, M. Fasih |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 3 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 349 KB |
| Title: | A NEW DESIGN METHOD FOR LOW SIDELOBE LEVEL LOG-PERIODIC DIPOLE ANTENNAS |
| Abstract: | A new design procedure for log-periodic dipole arrays is presented in this paper. In this method, either the scale factor or the number of dipole elements is selected, after the boom length, and the operating frequency region are specified. The procedure is applied iteratively, in conjunction to the Numerical Electromagnetic Code, to produce a design with low sidelobe levels. With this new procedure, the antenna designer has more control over the boom length; in older techniques, the boom length and the element spacing were dependent on previous calculations, which frequently resulted on unreasonable values Results for several designs are presented, showing the peak gain to peak-sidelobe level ratio, and the antenna gain as a function of frequency, for different scale factors and boom lengths, for a frequency range of 13 to 30 MHz. [Vol. 11, No. 3 (1996), pp 9-15] |
| Author(s): | James K. Breakall, Rafael A. Rodriguez Solis, James K. Breakall, Rafael A. Rodriguez Solis |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 3 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 445 KB |
| Title: | NUMERICAL EVALUATION OF SINGULAR INTEGRANDS IN THE APPLICATION OF THE CHARGE SIMULATION METHOD WITH DISTRIBUTED CHARGE DENSITY |
| Abstract: | As it is well known the Charge Simulation Method is a numerical method for the computation of the electric field in three-dimensional problems, based on the concept of the substitution of the electrodic geometry with a series of elementary charge suitably arranged. In this paper we will show a possible, useful way to overpass the difficulties arising in the numerical computations on the integral expression of the electric potential in the contour points where the boundary conditions are imposed, when distributed surface charges are used in the simulation. The numerical approach presented here allows us to evaluate with accuracy the potential coefficients on the metallic surfaces, avoiding the presence of oscillatory numerical solutions in the computation of the electric potential and of the electric field strength around the electrodes, that generally occurs when discrete charges are used in the simulation. [Vol. 11, No. 3 (1996), pp 16-24] |
| Author(s): | Ermanno Cardelli, Loris Faina, Ermanno Cardelli, Loris Faina |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 3 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 482 KB |
| Title: | MEASURED RCS POLAR CONTOUR MAPS FOR CODE VALIDATION |
| Abstract: | Measured radar cross-section (RCS) data as a function of the angle of incidence and of the frequency over a wide range provide an excellent basis for code validation. This paper examines the RCS of six targets measured as a function of the angle of incidence of the plane wave, and of the frequency, through and beyond the resonance range of target size. The RCS is presented as a function of frequency and incidence angle using a color contour map in a polar format, with the radius proportional to the frequency. Such polar contour maps exhibit striking patterns to the underlying scattering mechanisms and target geometry. The RCS as a function of incidence angle and frequency is available from the authors for an extensive collection of targets. [Vol. 11, No. 3 (1996), pp 25-43] |
| Author(s): | C.L. Larose, C.W. Trueman, C.L. Larose, C.W. Trueman |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 3 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 2808 KB |
| Title: | AN EFFICIENT METHOD OF ANALYSIS OF CO-PLANAR DIPOLE ARRAY ANTENNAS |
| Abstract: | Generalized impedance formulas for non-uniform array configurations based on the improved Circuit Theory (ICT) are presented for the first time in an English text. To further enhance the ICT as an accurate and fast method for evaluations, a new and more com pact closed-form formula is derived to replace a function requiring time intensive numerical integration during the implementation of the of the ICT algorithm in co-planar dipole array antenna evaluations. The resulting ICT computational scheme reduces the required CPU time by a factor of two and has the same order of accuracy as the conventional MoM. The new ICT implementation would be of considerable use as a Computer Aided Design (CAD) tool of co-planar dipole array antennas. [Vol. 11, No. 3 (1996), pp 44-54] |
| Author(s): | A. I. Imoro, N. Inagaki, N. Kikuma, A. I. Imoro, N. Inagaki, N. Kikuma |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 3 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 848 KB |
| Title: | AN ALGORITHM FOR SOLUTION OF THE INVERSE ELECTROMAGNETIC LIQUID METAL CONFINEMENT PROBLEM |
| Abstract: | The design of an electromagnetic levitation system for large amounts of liquid metal requires the solution of an inverse field problem. The objective is to calculate the electromagnetic pressure distribution which corresponds to a specific metallo-static head. This paper describes an algorithm for the design of coil systems which will produce the desired pressure distribution. The technique is illustrated by the design of a torroidal levitation system. [Vol. 11, No. 3 (1996), pp 55-62] |
| Author(s): | G.J. Bendzsak, G.J. Bendzsak |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 3 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 687 KB |
| Title: | COMPARISON OF MAGNETICALLY INDUCED ELF FIELDS IN HUMANS COMPUTED BY FDTD AND SCALAR POTENTIAL FD CODES |
| Abstract: | This paper presents a detailed numerical comparison of the magnetically-induced extremely low-frequency electric field and current density within an anatomically realistic model of the full human body, as computed using two different numerical techniques. The first technique is a recently-described full-wave quasi-static finite-difference time-domain (FDTD) method. The use of a time-ramped excitation involving pairs of oppositely-directed plane waves allows for the calculation of decoupled magnetic and electric induction in complex heterogeneous bodies, in relatively short (5 ns) simulation times. The second method is an implementation of Stevenson's method applied for isolated conducting bodies. With the lowest-order external magnetic field represented by a vector potential, the lowest-order internal electric field can be represented by a scalar conduction potential, and the magnetically-induced contribution can be calculated in isolation. Both methods have an underlying similarity in their finite-difference approach, but are nevertheless very distinct. Each code was used to calculate the fields, induced by three orthogonal uniform magnetic fields, in a 7.2 mm-resolution human full-body model. Three-dimensional correlation coefficients of better than 99.9998% were observed between current densities computed by the two methods. Individual edge electric fields typically agree to 3 significant digits. [Vol. 11, No. 3 (1996), pp 63-71] |
| Author(s): | Trevor W. Dawson, Jan De Moerloose, Maria A. Stuchly, Trevor W. Dawson, Jan De Moerloose, Maria A. Stuchly |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 3 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 693 KB |
| Title: | ANALYTIC VALIDATION OF A THREE-DIMENSIONAL SOLAR-POTENTIAL FINITE- DIFFERENCE CODE FOR LOW-FREQUENCY MAGNETIC INDUCTION |
| Abstract: | This paper presents a detailed comparison of numerical and analytical calculations of the low-frequency electric and current density fields, induced by an applied uniform axial magnetic field, in an equatorially stratified sphere having the conductivity distribution Rho (_)=Rho0e- cos( _) with p {1,2} and > 0. As shown by the analytic solution, the resulting induced fields are fully three-dimensional, and the model therefore serves as a rigorous test of numerical codes The numerical method is a scalar-potential finite-difference scheme based on Stevenson's method for isolated conducting bodies. This computer code was recently shown to provide excellent agreement with results computed independently by a modified Finite-Difference Time-Domain method. Nevertheless, both codes share some underlying similarities, such as their common use of parallelepiped material voxels to represent the conductivity distribution, and of an edge-based staggered to model the electric fields. Therefore, it is of value to compare the numerical results with analytic ones The analytic model has a freely adjustable contrast parameter, and supports both pi and 2pi-periodic conductivity distributions. Numerical and analytical results are compared for several configurations. Full three-dimensional volumetric correlation coefficients are typically of the order of 99% or better. As might be expected, the main differences occur at the surface of the sphere, where the true circumferential fields are most poorly approximated by the staircasing approximation inherent the numerical approximation. [Vol. 11, No. 3 (1996), pp 72-81] |
| Author(s): | Trevor W. Dawson, Maria A. Stuchly, Trevor W. Dawson, Maria A. Stuchly |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 3 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 767 KB |
| Title: | THE GRADIENT ASSOCIATED CONJUGATE DIRECTION METHOD |
| Abstract: | A new conjugate direction (CD) based method, GaCD by name, is addressed with its full derivations. Comparison with some commonly used CD methods is made, concluding that the GaCD method is among the best of them, in terms of an assessment number. A practical example is presented in which a waveguide-microstrip transition section is optimized with respect to its transmission parameter S2l. The measurement of the transition agrees very well with the numerical results. [Vol. 11, No. 3 (1996), pp 82-96] |
| Author(s): | Min Zhang, Min Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 3 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 1873 KB |
| Title: | THE NEC2 RADIATION PATTERNS OF UNDER-SEGMENTED WIRE GRID MODELS OF A FIGHTER AIRCRAFT COMPARED TO MEASUREMENTS |
| Abstract: | This paper presents results of a NEC2 method of moments evaluation of VHF/UHF antennas on a wire grid model of a fighter aircraft. The study shows that practically useful radiation patterns results can be obtained when the grid model is considerably under-segmented in aircraft regions which are electrically far removed from the antennas. Normal modelling guide-lines requires approximately 35000 segments for the fighter grid model at 400 MHz; judicious under-segmentation gave useful results using a model comprising 5000 segments. This reduction in segments reduced computer time by a factor of 343 and memory requirements is reduced by a factor of 18. NEC2 radiation patterns are compared to measurements on a l/lOth scale model which was performed in an anechoic chamber compact range. [Vol. 10, No. 1 (1995), pp 5-14] |
| Author(s): | 0. Givati, A.P.C. Fourie, 0. Givati, A.P.C. Fourie |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 1 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 667 KB |
| Title: | A SURFACE INTEGRAL EQUATION FORMULATION FOR LOW CONTRAST SCATTERERS BASED ON RADIATION CURRENTS |
| Abstract: | A new surface integral equation formulation based on radiation currents is presented. Numerical problems have been observed when treating low contrast scatterers with surface integral equation formulations based on the total equivalent currents. These problems result because the total equivalent currents are large compared with the radiation currents for low contrast materials. The surface integral equation formulation presented here avoids this problem by solving directly for the radiation currents. [Vol. 10, No. 1 (1995), pp 15-18] |
| Author(s): | Paul M. Goggans, Allen W. Glisson, Paul M. Goggans, Allen W. Glisson |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 1 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 423 KB |
| Title: | THE MEASURED EQUATION OF INVARIANCE METHOD APPLIED TO RANDOMLY ROUGH SURFACES |
| Abstract: | The Measured Equation of Invariance (MEI) method has received considerable attention recently. Unlike more traditional numerical techniques, MEI solutions are obtained by inversion of a relatively small and sparse matrix. Therefore, the MEI method can potentially provide a solution much more quickly than other techniques. To date, the MEI method has been applied primarily to discrete objects. In this paper, bistatic radar cross sections for one-dimensional, perfectly conducting, randomly rough surfaces are obtained using the MEI method. The implementation suitable for this problem requires some modification and enhancement of the original algorithm to achieve the desired accuracy. These algorithmic changes can be applied to the discrete scattering problem as well. Monte Carlo results for the bistatic scattering cross section for surfaces with Gaussian statistics and satisfying a Gaussian roughness spectrum are compared to those from another technique and excellent agreement is obtained. [Vol. 10, No. 1 (1995), pp 19-30] |
| Author(s): | John B. Schneider, Shira Lynn Broschat, John B. Schneider, Shira Lynn Broschat |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 1 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 1519 KB |
| Title: | A GUIDE TO IMPLEMENTATIONAL ASPECTS OF THE SPATIAL DOMAIN INTEGRAL EQUATION ANALYSIS OF MICROSTRIP ANTENNAS |
| Abstract: | In the analysis of microstrip radiating structures integral equation methods rate among the more accurate approaches. By far the most demanding part in the use of these methods is the actual numerical implementation. This paper presents a detailed illustrated description of the numerical implementation of a spatial domain mixed-potential integral equation analysis of microstrip radiating structures. [Vol. 10, No. 1 (1995), pp 40-51] |
| Author(s): | Louis T. Hildebrand, Derek A. McNamara, Louis T. Hildebrand, Derek A. McNamara |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 1 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 1533 KB |
| Title: | PERFORMANCE OF A CHARACTERISTIC-BASED, 3-D, TIME-DOMAIN MAXWELL EQUATIONS SOLVER ON THE INTEL TOUCHSTONE DELTA |
| Abstract: | A characteristic-based, windward numerical procedure for solving three-dimensional Maxwell equations in the time domain has been successfully ported to the Intel Touchstone Delta multicomputer. The numerical results by concurrent computation duplicated the earlier simulations of an oscillating electric dipole on a vector processor and compared well with the exact solutions. The parallelized code is scalable up to 512 nodes and incurs only up to 7.6% performance degradation. The sustained data processing rate is clocked at 6.551 Gigaops. However, the data I/O process is unscalable on the shared memory system. [Vol. 10, No. 1 (1995), pp 52-62] |
| Author(s): | J. S. Shang, Kueichien C. Hill, Donald A. Calahan, J. S. Shang, Kueichien C. Hill, Donald A. Calahan |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 1 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 1094 KB |
| Title: | ON THE APPLICABILITY OF THE BICONJUGATE GRADIENT FFT METHOD FOR THE THIN CONDUCTING PLATE PROBLEM |
| Abstract: | The application of the Biconjugate Gradient FFT method to the thin conducting plate problem is investigated. Upon comparing with a Conjugate Gradient FFT method, it is found that the Biconjugate Gradient solution requires a relatively larger error tolerance to achieve a comparatively well-behaved current distribution. Coupled with the requirement of only one matrix-vector product per iteration, the computational cost of the Biconjugate Gradient method is, thus, much smaller than those previously reported in the literature. Of particular importance is the use of the incident electric field as a starting estimate to alleviate the non-convergence behaviour which is usually associated with the application of a Biconjugate Gradient approach to conducting plates at grazing angle. For other angles of incidence, it is shown that this procedure also accelerates the resulting convergence rates as compared to those obtained by simply using zero as an initial estimate. [Vol. 10, No. 1 (1995), pp 63-68] |
| Author(s): | T. V. TRAN, A. McCOWEN, T. V. TRAN, A. McCOWEN |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 1 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 702 KB |
| Title: | REVISED INTEGRATION METHODS IN A GALERKIN BOR PROCEDURE |
| Abstract: | Several relatively simple numerical changes improve the speed and accuracy of the early Mautz and Harrington discretization procedure for boundary element method calculations of scattering from axially symmetric bodies. This method is still in common use in programs such as CICERO and GRMBOR. For a fixed set of geometry points, changes in the azimuthal (o) integration reduce computer time, especially when lossy materials are involved. Changes in the integration along the generating curve (t) improve accuracy. The most interesting of these is the use of the equal area rule from parallel wire modeling of solid surfaces to answer the old question of the optimal constant for dealing with an integrable singularity in some of the t integrals. Some of these changes are applicable to a variety of integral equations and boundary conditions. Most of them can be implemented with little programming effort. Tests are shown for difficult cases involving spheres, and Mie series calculations are used for comparison. [Vol. 10, No. 2 (1995), pp 5-16] |
| Author(s): | David R. Ingham, David R. Ingham |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 2 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 886 KB |
| Title: | HIGHER-ORDER FDTD METHODS FOR LARGE PROBLEMS |
| Abstract: | The Finite-Difference Time-Domain (FDTD) algorithm provides a simple and efficient means of solving Maxwell's equations for a wide variety of problems. In Yee's uniform grid FDTD algorithm the derivatives in Maxwell's curl equations are replaced by central difference approximations. Unfortunately, numerical dispersion and grid anisotropy are inherent to FDTD methods. For large computational domains, e.g., ones that have at least one dimension forty wavelengths or larger, phase errors from dispersion and grid anisotropy in the Yee algorithm (YA) can be significant unless a small spatial discretization is used. For such problems, the amount of data that must be stored and calculated at each iteration can lead to prohibitive memory requirements and high computational cost. To decrease the expense of FDTD simulations for large scattering problems two higher-order methods have been derived and are reported here. One method is second-order in time and fourth-order in space (2-4); the other is second-order in time and sixth-order in space (2-6). Both methods decrease grid anisotropy and have less dispersion than the YA at a set discretization. Also, both permit a coarser discretization than the YA for a given error bound. To compare the accuracy of the YA and higher-order methods both transient and CW simulations have been performed at a set discretization. In general, it has been found that the higher-order methods are more accurate than the YA due to the reduced grid anisotropy and dispersion. However, the higher-order methods are not as accurate as the YA for the simulation of surface waves. This is attributed to the larger spatial stencil used in calculating the fields for the higher-order methods. More research is needed to examine the accuracy of higher-order methods at material boundaries. [Vol. 10, No. 2 (1995), pp 17-29] |
| Author(s): | Charles W. Manry Jr, Shira L. Broschat, John B. Schneider, Charles W. Manry Jr, Shira L. Broschat, John B. Schneider |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 2 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 1102 KB |
| Title: | RADAR CROSS SECTION OF A RECTANGULAR CAVITY- A MASSIVELY PARALLEL CALCULATION |
| Abstract: | A sequential code that calculates the radar cross section of a rectangular waveguide cavity was modified to execute on a MasPar MP-l massively parallel computer with a SIMD architecture. The code uses the mode matching method of analysis to produce a set of matrix equations. Steps taken to accomplish the parallelization are discussed and some specific examples of program modification are presented. Timing results for wideband data are given that demonstrate the power of parallel computers for this type of application. Suggestions are made for further improvements as increased memory space becomes available. [Vol. 10, No. 2 (1995), pp 30-45] |
| Author(s): | L. D. Vann, L.T. Willet, J.S. Bagby, H.F. Helmken, L. D. Vann, L.T. Willet, J.S. Bagby, H.F. Helmken |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 2 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 835 KB |
| Title: | A NUMERICAL TECHNIQUE TO DETERMINE ANTENNA PHASE CENTER LOCATION FROM COMPUTED OR MEASURED PHASE DATA |
| Abstract: | In many antenna applications, it is a requirement to have knowledge of the antenna phase center properties. Many interpretations of antenna phase center and its apparent location exist. This paper will present a formulation for determination of antenna phase center location derived using the antenna phase response. A fortran program, developed from the formulations, is used to calculate phase center location for several examples which include both computed and simulated measured phase data. A simple numerical technique is presented that processes measured phase data allowing accurate phase center determination. [Vol. 10, No. 2 (1995), pp 46-62] |
| Author(s): | Steven R. Best, James M. Tranquilla, Steven R. Best, James M. Tranquilla |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 2 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 1044 KB |
| Title: | CONFORMAL ARRAY DESIGN SOFTWARE |
| Abstract: | A powerful conformal array design computer program can be developed by modification of a physical optics based array fed reflector analysis computer program. [Vol. 10, No. 2 (1995), pp 63-74] |
| Author(s): | H.K. Schuman, H.K. Schuman |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 2 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 556 KB |
| Title: | COMPARISON OF THE INPUT IMPEDANCE OF MONOPOLE ANTENNAS OBTAINED BY NEC, MINlNEC, AND MEASUREMENTS |
| Abstract: | This paper compares the input impedance of monopole antennas numerically calculated by NEC and MININEC with experimental results. This comparison determines the limitation of these two computer codes used for modeling more complicated structures. Two groups of monopoles are considered. The first group consists of eight electrically thin monopoles of length .28 meters (.235 wavelengths at 252 MHz) and radii of .4064, . 7874, 1.168, 1.562, 2.390, 3.162, 6.350, and 7.920 millimeters (.341E-3, .661E-3, .981E-3, 1.31E-3, 2.01E-3, 2.66E-3, 5.33E-3, and 6.65E-3 wavelengths at 252 MHz). For this group, impedance calculations were compared to measurements over the band of 237-267 MHz. The second group consists of five electrically thick monopoles of length .2 wavelengths and radii of .0509, .0635, .0847, .1129, and .1270 wavelengths. For the second group impedance calculations were compared with measurements of tubular monopoles with flat ends. The results of this paper show that the extended kernel option of NEC predicted measured monopole impedance measurements more accurately than MININEC. [Vol. 10, No. 2 (1995), pp 75-85] |
| Author(s): | R. J. Bauerle, J. K. Breakall, R. J. Bauerle, J. K. Breakall |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 2 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 745 KB |
| Title: | ACCURATE MODELING OF STEPPED-RADII ANTENNAS |
| Abstract: | The LP8, eight element, log periodic antenna made by M2 Enterprises has recently been modeled at Penn State University using both Version 2 and 4 of the Numerical Electromagnetics Code (NEC). The antenna has a steppedradii element construction and operates from 10 to 30 MHz. The stepped-radii element construction is difficult to model using NEC Version 2. To model a stepped-radii antenna with this version, equivalent lengths of constant radii are calculated using another method of moments program called ELNEC. These equivalent lengths replaced the original stepped radii elements of the log periodic antenna during the modeling. Fortunately, NEC Version 4 can simulate the stepped-radii elements directly, which makes the modeling procedure much easier and accurate. Both NEC models show good agreement with the measurements when compared to VSWR measurements. The authors hope that this paper will help others with similar modeling problems who cannot yet obtain NEC Version 4. [Vol. 10, No. 2 (1995), pp 86-95] |
| Author(s): | A. I. Bauerle, J. K. Breakall, A. I. Bauerle, J. K. Breakall |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 2 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 726 KB |
| Title: | MUTUAL VALIDATION OF THREE PROGRAMS FOR NUMERIC ANTENNA COMPUTATIONS |
| Abstract: | The numerical results obtained by three different codes, GALNEC, WARAN and NEC-2 are compared for thin dipoles and thick ones with hemispherical end caps and for arrays of such collinear dipoles. The electric field integral equation and Galerkin's method are used in the code GALNEC where solid thick dipole bodies are implemented. Mei's (1965) integral equation and collocation technique are wed in the code WARAN, where thick dipoles are simulated as arrays of thin wires. Good agreement has been obtained for current distri- butions and input and mutual impedances. [Vol. 10, No. 2 (1995), pp 96-101] |
| Author(s): | Andrew A. Efanov, Harald Schopf, Bernhard Schnizer, Andrew A. Efanov, Harald Schopf, Bernhard Schnizer |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 2 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 421 KB |
| Title: | Using GPUs for Accelerating Electromagnetic Simulations |
| Abstract: | The computational power and memory bandwidth of graphics processing units (GPUs) have turned them into attractive platforms for general-purpose applications at significant speed gains versus their CPU counterparts [1]. In addition, an increasing number of today's state-ofthe- art supercomputers include commodity GPUs to bring us unprecedented levels of performance in terms of raw GFLOPS and GFLOPS/cost. Inspired by the latest trends and developments in GPUs, we propose a new paradigm for implementing on GPUs some of the major aspects of electromagnetic simulations, a domain traditionally used as a benchmark to run codes in some of the most expensive and powerful supercomputers worldwide. After reviewing related achievements and ongoing projects, we provide a guideline to exploit SIMD parallelism and high memory bandwidth using the CUDA programming model and hardware architecture offered by Nvidia graphics cards at an affordable cost. As a result, performance gains of several orders of magnitude can be attained versus threadlevel methods like pthreads used to run those simulations on emerging multicore architectures |
| Author(s): | M. Ujaldon |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 4 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 309 KB |
| Title: | Unconditionally Stable Locally One-Dimensional FDTD Methods for Efficient Electromagnetic Simulations |
| File Type: | Conference Paper |
| Issue: | Volume: Optoelectronic modeling Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 77 KB |
| Title: | Tuning Space Mapping for Microwave Design Optimization |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Simulations using Sonnet Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 336 KB |
| Title: | Time Domain Modeling of Active Materials |
| File Type: | Conference Paper |
| Issue: | Volume: S48 Computational Nanophotonics: Advanced Numerical Methods and Applications II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 339 KB |
| Title: | The Way from Natural to Artificial |
| File Type: | Conference Paper |
| Issue: | Volume: 2-1-C Properties, Modelling and Novel Concepts of Artificial Electromagnetic Structures I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 235 KB |
| Title: | The Validationof EM Modelling Codes. A User Viewpoint |
| Abstract: | Computer codes for solving radiation and scattering problems have becomed powerful and widely available. The user of such a code must initially convince himself that his copy of the code executes correctly on his specific computer with his particular compiler. He must then build up expertise in constructing models for solution by the code which obey the restrictions imposed by the "modelling guildelines" accompanying the code in a user's manual. Users often want to solve "real" problems that do not conform to the problem geometry envisaged by the code writer. The user replaces the "real" structure with a computer model solvable by the code, and which obeys the modelling guidelines. The user must then carry out a "model validation" in which the computer model is tested against full-scale or scale model measurements. A successful "model validation" contributes to the user community's "experience base" and lends confidence to both the computer code and to the modelling process. Sometimes an unsuccessful attempt at modeling exposes a genuine limitation of the code. Then a new "modelling guideline" can be formulated to aid other users in avoiding the same difficulties. This paper reviews code development to highlight the origin of "modelling guidelines", and how they are extended by the user community. From the user's point of view, the "experience base" is augmented whenever a successful "model validation" is carried out and reported. Several examples are presented of the difficulties that may be encountered in computer modelling, and how such difficulties lead to further "modelling guidelines" aimed at aiding others in solving similar problems. |
| Author(s): | S.J. Kubina, C.W. Trueman, S.J. Kubina, C.W. Trueman |
| File Type: | Journal Paper |
| Issue: | Volume: 4 Number: 3 Year: 1989 |
| Download Link: | Click here to download PDF File Size: 731 KB |
| Title: | The Success of GPU Computing in Applied Electromagnetics |
| Abstract: | In the field of electromagnetic modeling, whether it is the complex designs for engineered materials or devices and components integrated within their natural environments, there is a big drive for highly efficient numerical techniques to model the performance of complex structures. This often cannot be achieved by conventional computer systems, but rather through using the so-called high performance computing (HPC) systems that utilize hardware acceleration. We review recent General Purpose Graphics Processing Units (GPGPU) computing strategies introduced in four fields of computational electromagnetics: Finite-Difference Time-Domain (FDTD), Finite Elements Method (FEM), Method of Moments (MoM) and ElectroMagnetic Ray Tracing (EMRT). |
| Author(s): | A. Capozzoli, O. Kilic, C. Curcio, A. Liseno |
| File Type: | Express Journal Paper |
| Issue: | Volume: 1 Number: 4 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1478 KB |
| Title: | The Success of GPU Computing in Applied Electromagnetics |
| Abstract: | In the field of electromagnetic modeling, whether it is the complex designs for engineered materials or devices and components integrated within their natural environments, there is a big drive for highly efficient numerical techniques to model the performance of complex structures. This often cannot be achieved by conventional computer systems, but rather through using the so-called high performance computing (HPC) systems that utilize hardware acceleration. We review recent General Purpose Graphics Processing Units (GPGPU) computing strategies introduced in four fields of computational electromagnetics: Finite-Difference Time-Domain (FDTD), Finite Elements Method (FEM), Method of Moments (MoM) and ElectroMagnetic Ray Tracing (EMRT). |
| Author(s): | A. Capozzoli, O. Kilic, C. Curcio, A. Liseno |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1501 KB |
| Title: | The Success of GPU Computing in Applied Electromagnetics |
| Abstract: | In the field of electromagnetic modeling, whether it is the complex designs for engineered materials or devices and components integrated within their natural environments, there is a big drive for highly efficient numerical techniques to model the performance of complex structures. This often cannot be achieved by conventional computer systems, but rather through using the so-called high performance computing (HPC) systems that utilize hardware acceleration. We review recent General Purpose Graphics Processing Units (GPGPU) computing strategies introduced in four fields of computational electromagnetics: Finite-Difference Time-Domain (FDTD), Finite Elements Method (FEM), Method of Moments (MoM) and ElectroMagnetic Ray Tracing (EMRT). |
| Author(s): | A. Capozzoli, O. Kilic, C. Curcio, A. Liseno |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1501 KB |
| Title: | The Locally-corrected Nystrom Method: Progress and Challenges |
| File Type: | Conference Paper |
| Issue: | Volume: S05 Locally Corrected Nystrom Method and its Applications Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 188 KB |
| Title: | THE COMPUTATION OF LINEAR DISPERSIVE ELECTROMAGNETIC WAVES |
| Abstract: | Numerical solutions of the equations describing electromagnetic pulse propagation in geometrically complex Debye-dispersive dielectrics are used in the development of safety standards for human exposure to non-ionizing radiation. Debye dispersion is a relaxation process, a phenomenon which occurs when the underlying material is forced into non-equilibrium due to the passing waves. This relaxation is typically stiff in applications, and the system of equations is then singularly perturbed. Such systems are notoriously expensive to solve with standard numerical methods. We review previous work related to the numerical solution of such problems, and consider a representative numerical scheme in order to elucidate the nature of the challenge posed to Computational Electromagnetics by the stiffness. Further. an analysis of the stiffness leads us to propose a scheme that seems "natural" for the problem at hand. [Vol. 11, No. 1 (1996), pp 8-16, Special issue on Applied Mathematics: Meeting the challenges presented by computational electromagnetics] |
| Author(s): | Peter G. Petropoulos, Peter G. Petropoulos |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 1 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 708 KB |
| Title: | Teaching Electromagnetics via Virtual Tools and a New Electromagnetic Engineering Program (EMEP) |
| File Type: | Conference Paper |
| Issue: | Volume: CEM for EM Education Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 144 KB |
| Title: | Spoof Surface Plasmons for Guiding and Radiating Electromagnetic Waves |
| File Type: | Conference Paper |
| Issue: | Volume: 6-ME-1 Advanced Plate Antenna and Array Technologies II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 182 KB |
| Title: | Simulation and Optimization of Photonic Crystal Structures |
| File Type: | Conference Paper |
| Issue: | Volume: Computational Electromagnetics for Photonics Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 337 KB |
| Title: | Self-adjoint S-parameter Sensitivities for TLM problems |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Computer-Aided Design of Electromagnetic Structures and Devices Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 80 KB |
| Title: | Scalability of Hybrid Full Wave/Asymptotic EM Solver Techniques for Naval Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: S32 Recent Advances in Asymptotic Methods Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 2554 KB |
| Title: | Review of the Latest Feature Additions to the Electromagnetic Solver FEKO |
| File Type: | Conference Paper |
| Issue: | Volume: S44 EM Modeling Using FEKO I Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 1179 KB |
| Title: | Review of Six-Port Interferometer Technology |
| File Type: | Conference Paper |
| Issue: | Volume: Six Port Technology in Software Radio Wireless Communication Systems Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 198 KB |
| Title: | Review of SIW Power Capacity and Verification on Multi-Physics Simulation |
| File Type: | Conference Paper |
| Issue: | Volume: 6-ME-3 Multi-physics Simulation of Coupled Field-Circuit Problems Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 364 KB |
| Title: | Review of Selected New Features in FEKO 2018 |
| File Type: | Conference Paper |
| Issue: | Volume: S23 EM Modeling Using FEKO I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 258 KB |
| Title: | Review of RF Cloaking Techniques for Antenna Applications |
| Abstract: | This paper reviews the background phenomenon of various cloaking techniques such as transformation optics, transmission line network, microwave network cloak, scattering cancellation techniques in the applications of antenna field particularly in hiding the obstacle from the electromagnetic source and reducing the mutual coupling between two antennas that was placed closed to each other. Cloaking at multiple frequencies in each cloaking techniques are also compared. The comparative study showed that the scattering cancellation technique based on aperiodic Frequency Selective Surfaces (FSS) structure will dominate the electromagnetic cloaking field in near future. |
| Author(s): | N. Kumutha, K. Hariharan, N. Amutha, B. Manimegalai |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 8 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1886 KB |
| Title: | Review of Recent Advances and Future Challenges in Antenna Measurement |
| Abstract: | This paper reviews the last advances in Antenna Measurement Field that took place during the previous years in order to analyse the challenges for the antenna measurement community, both industrial and academic, for the future years. The paper begins with an introductory review of the antenna measurement methodologies innovations, continuing with measurement systems technical improvements and concluding with the challenges for the antenna measurement community in the close future. |
| Author(s): | M. Sierra-Castañer |
| File Type: | Express Journal Paper |
| Issue: | Volume: 1 Number: 2 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 370 KB |
| Title: | Review of Recent Advances and Future Challenges in Antenna Measurement |
| Abstract: | This paper reviews the last advances in Antenna Measurement Field that took place during the previous years in order to analyse the challenges for the antenna measurement community, both industrial and academic, for the future years. The paper begins with an introductory review of the antenna measurement methodologies innovations, continuing with measurement systems technical improvements and concluding with the challenges for the antenna measurement community in the close future. |
| Author(s): | M. Sierra-Castañer |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 1 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1558 KB |
| Title: | Review of Recent Advances and Future Challenges in Antenna Measurement |
| Abstract: | This paper reviews the last advances in Antenna Measurement Field that took place during the previous years in order to analyse the challenges for the antenna measurement community, both industrial and academic, for the future years. The paper begins with an introductory review of the antenna measurement methodologies innovations, continuing with measurement systems technical improvements and concluding with the challenges for the antenna measurement community in the close future. |
| Author(s): | M. Sierra-Castañer |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 1 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1558 KB |
| Title: | Review of Complex Looped FDTD and its new applications |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling Techniques for Periodic Structures and Metamaterial Applications - I Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 224 KB |
| Title: | Review of Advanced EM Modeling Techniques in the Computer Code FEKO |
| File Type: | Newsletter Paper |
| Issue: | Volume: 18 Number: 2 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 709 KB |
| Title: | Review -- Grid Computing for Electromagnetics |
| File Type: | Newsletter Paper |
| Issue: | Volume: 20 Number: 1 Year: 2005 |
| Download Link: | Click here to download PDF File Size: 227 KB |
| Title: | Retrospect of Space Solar Power Stations History |
| File Type: | Conference Paper |
| Issue: | Volume: 8-TP-4 In Celebration of 70th Birthday of Prof. Jia-dong Xu II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 1161 KB |
| Title: | Retrospect of Space Solar Power Stations History |
| File Type: | Conference Paper |
| Issue: | Volume: 10-TE-4 In Celebration of 70th Birthday of Prof. Jia-dong Xu III Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 1161 KB |
| Title: | Response Correction Techniques for Microwave Design Optimization |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic-Simulation-Driven-Design: Modeling and Optimization Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 275 KB |
| Title: | Reconfigurable Origami Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: S42 Physically Reconfigurable Antennas and Arrays: Design, Modeling and Materials I Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 837 KB |
| Title: | Recent Advances in Sensitivity Analysis with Frequency-Domain Full-Wave EM Solvers |
| Abstract: | This paper introduces recent developments in efficient sensitivity analysis with numerical electromagnetic solvers in the frequency domain. We start by reviewing our original discrete approaches for sensitivity analysis. We then propose and investigate, for the first time, two new discrete approaches which enhance the accuracy of the estimated derivatives. All four introduced approaches are based on the adjointvariable method and target solvers on structured grids. Discussion and comparison of the accuracy and convergence for the different approaches are also given. Examples include waveguide and printed structures. |
| Author(s): | S. M. Ali, N. K. Nikolova, M. H. Bakr, S. M. Ali, N. K. Nikolova, M. H. Bakr |
| File Type: | Journal Paper |
| Issue: | Volume: 19 Number: 3 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 256 KB |
| Title: | RAY-TRACING TECHNIQUES FOR MOBILE COMMUNICATIONS |
| Abstract: | In this paper an application for mobile communication of several ray-tracing techniques is presented. The techniques work in combination with deterministic propagation models based on GTD/UTD techniques. Several ray-tracing techniques are reviewed and some results applying one of them, the Angular Zeta Buffer (AZB) method for urban and indoor scenarios are shown, obtaining in all the cases good results comparing with measurements. |
| Author(s): | O. Gutierrez, F. Saez de Adana, I. Gonzalez, J. Perez, M. E. Cetedra, O. Gutierrez, F. Saez de Adana, I. Gonzalez, J. Perez, M. E. Cetedra |
| File Type: | Journal Paper |
| Issue: | Volume: 15 Number: 3 Year: 2000 |
| Download Link: | Click here to download PDF File Size: 2460 KB |
| Title: | Ray-Launching Geometrical Optics in FEKO: A Summary of the Last Four Years of Intensive Development |
| File Type: | Conference Paper |
| Issue: | Volume: 10-TE-3 Recent Advances on Electromagnetics Modeling and Simulation Techniques II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 490 KB |
| Title: | Radar cross section of exhaust ions in HF region |
| File Type: | Conference Paper |
| Issue: | Volume: High Frequency Techniques Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 251 KB |
| Title: | Progress on Microwave Devices Fabricated Using Stereolithography 3-D Printing Technique |
| File Type: | Conference Paper |
| Issue: | Volume: 2-3-C Advanced Manufacturing Technologies for Microwave Devices Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 390 KB |
| Title: | Progress of Tensor-Based High-Dimensional Uncertainty Quantification of Process Variations |
| File Type: | Conference Paper |
| Issue: | Volume: S05 Locally Corrected Nystrom Method and its Applications Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 214 KB |
| Title: | Progress and Future Work on the NS-FDTD Method |
| File Type: | Conference Paper |
| Issue: | Volume: Finite Difference Methods Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 464 KB |
| Title: | Physics-Based Aggregate-Functions Approaches to Large Mom Problems |
| Abstract: | Aggregate functions approaches construct efficient MoM basis functions by suitably grouping standard (e.g. Rao-Wilton- Glisson) functions. The application domains, objectives and related means of achieving them can be significantly different. In this paper we review some recent advances in aggregatefunctions methods, putting them in a unifying perspective. We address matrix compression, multi-resolution sets, low- and high-frequency constructs. They can reduce the degrees of freedom of the problem so as to allow a direct, iteration-free solution, or can accelerate the convergence rate of iterative methods. We analyze compressive methods in more detail, providing general discussion and specific implementation examples. |
| Author(s): | L. Matekovits, G. Vecchi, F. Vico |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 2 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 941 KB |
| Title: | PARALLEL MATRIX SOLVERS FOR MOMENT METHOD CODES FOR MIMD COMPUTERS |
| Abstract: | Parallel algorithms are presented that are suitable for the solution of the system of linear equations generated by moment method problems on local memory Multiple Instruction, Multiple Data (MIMD) parallel computers. The two most widely used matrix solution algorithms in moment method codes are described, namely the conjugate gradient (CG) method and LU decomposition. The underlying philosophy of parallelism is briefly reviewed. Suitable parallel algorithms are then described, presented in pseudo-code, their timing behaviour analyzed the- oretically, and timing results measured on a particular MIMD computer- -a transputer array --are presented and compared to the theoretical timing models. It is concluded that efficient parallel algorithms for both the CG and LU exist and that MIMD computers offer an attractive computational platform for the solution of moment method problems with large numbers of unknowns. [Vol. 8, No. 2 (1993), pp 144-175] |
| Author(s): | David B. Davidson, David B. Davidson |
| File Type: | Journal Paper |
| Issue: | Volume: 8 Number: 2 Year: 1993 |
| Download Link: | Click here to download PDF File Size: 1827 KB |
| Title: | PARALLEL COMPUTATION OF LARGE-SCALE ELECTROMAGNETIC FIELD DISTRIBUTIONS |
| Abstract: | Some experience of the use of high-frequency electromagnetics software on parallel computers is reported. Types of such computers are reviewed and approaches to the parallelisation of existing serial software are discussed. A practical large-scale problem is presented involving the modelling in very fine detail of electromagnetic penetration into biological systems. This was tested on state-of-the-art parallel computers and important practical and strategic aspects of the experience derived are discussed. It was found that considerable programmer effort was required to optimise the software to use the computer architecture effectively, but that efficient acceleration of the run-times of typical computational tasks could be achieved, provided that the tasks were large and were partitioned optimally. |
| Author(s): | Peter S. Excell, Adam D. Tinniswood, Kathleen Haigh-Hutchinson, Peter S. Excell, Adam D. Tinniswood, Kathleen Haigh-Hutchinson |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 2 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 2818 KB |
| Title: | Overview of Mesh Truncation Algorithms in PDEs for Maxwell Equations |
| File Type: | Conference Paper |
| Issue: | Volume: In Tribute To Dr. Zoltan Cendes Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 100 KB |
| Title: | Overview of Inverse Scattering, Imaging, and Parallel Computing |
| File Type: | Conference Paper |
| Issue: | Volume: Efficient Numerical Solutions of Large Multi-dimensional Inverse Scattering Problems Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 182 KB |
| Title: | Optimizing the Parallel Implementation of a Finite Difference Time Domain Code on a Multi-user Network of Workstations |
| Abstract: | The implementation of a parallel, three dimensional, finite difference time domain (FDTD) computer program is considered and applied to a test scattering problem on a multi-user network of desktop workstations. The computation has primarily been done on a local area network (LAN) using six identical HP 9000/715 workstations (i.e. a homogeneous environment) with the Parallel Virtual Machine (PVM) software being employed as the communications harness.In this paper the sequential and parallel FDTD approaches are reviewed. We investigate the factors which cause a reduction in efficiency in the latter, such as host allocation and load balancing. We propose a task migration process, which is efficient for the FDTD algorithm, as a partial solution. The advantages of this approach are discussed and further developments based on available computational resources are suggested |
| Author(s): | J. V. Mullan, C. J. Gillan, V. F. Fusco, J. V. Mullan, C. J. Gillan, V. F. Fusco |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 2 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 710 KB |
| Title: | Optimizing Multiple GPU FDTD Simulations in CUDA |
| File Type: | Conference Paper |
| Issue: | Volume: Parallel and Hardware Acceleration for Computational Electromagnetics Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 44 KB |
| Title: | On the numerical modeling of graphene and silicene for EM solvers |
| File Type: | Conference Paper |
| Issue: | Volume: Computational Methods in Nanoelectromagnetics Number: Year: 2014 |
| Download Link: | Login To Download (For Members) File Size: 301 KB |
| Title: | On the Discretization of Fredholm Integral Equations of First Kind Using Compactly Supported Wavelets |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Integral Equation Techniques Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 452 KB |
| Title: | Numerical Validation of a Boundary Element Method with Electric Field and Its Normal Derivative as the Boundary Unknowns |
| Abstract: | We recently developed a surface integral equation method where the electric field and its normal derivative are chosen as the boundary unknowns. After reviewing this formulation, we present preliminary numerical calculations that show good agreement with the known results. These calculations are encouraging and invite the further development of the numerical solution. |
| Author(s): | J. Markkanen, A. J. Yuffa, J. A. Gordon |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 2 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2963 KB |
| Title: | Numerical Validation of a Boundary Element Method With E and @E @N as the Boundary Unknowns |
| File Type: | Conference Paper |
| Issue: | Volume: S28 Computational Methods for Complex EM Domains, Integral Equation Methods Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 188 KB |
| Title: | Numerical Simulation Approaches for Phased Array Design |
| Abstract: | Abstract - This paper reviews the two well-known numerical simulation techniques that are widely used in antenna modeling; the finite-difference time-domain (FDTD) and the Method of Moments (MoM). The packages FDANT (prepared in Fortran language by using FDTD) and NEC2 (public domain code for the MoM) are used to model various types of antenna arrays, their advantages/disadvantages are discussed on characteristic design examples, and they are calibrated one against the other. Also, a simple Matlab package (ANTEN_GUI) for the visualization of radiation patterns, beam forming and beam steering capabilities of user-designed planar arrays of isotropic radiators (which can be used to test the above mentioned packages and as an educational tool, in e.g., antennas and propagation lectures) is introduced1. |
| Author(s): | L. Sevgi, L. Sevgi |
| File Type: | Journal Paper |
| Issue: | Volume: 21 Number: 3 Year: 2006 |
| Download Link: | Click here to download PDF File Size: 1360 KB |
| Title: | Neural Network Based Methods for Nonlinear Behavioral Modeling of RF and Microwave Circuits |
| File Type: | Conference Paper |
| Issue: | Volume: Microwave Modeling and CAD Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 202 KB |
| Title: | Near-field RCS Measurement and Microwave Imaging Diagnosis-A Review of NWPU Work |
| File Type: | Conference Paper |
| Issue: | Volume: 9-P-2 Poster Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 181 KB |
| Title: | Multiple Beam Antenna Technology for Satellite Communications Payloads |
| Abstract: | Abstract—This paper reviews multiple beam antenna (MBA) technologies that are applicable for satellite communications payloads. It provides design, performance analysis, and hardware implementation aspects of various types of MBAs that include reflector MBAs, phased array MBAs, and lens MBAs. Parametric design of these MBAs and RF analysis for coverage gain and inter-beam isolation are given. Recent advances and trends in MBA technologies for space applications are discussed. |
| Author(s): | S. Rao, M. Tang, C. Hsu, S. Rao, M. Tang, C. Hsu |
| File Type: | Journal Paper |
| Issue: | Volume: 21 Number: 3 Year: 2006 |
| Download Link: | Click here to download PDF File Size: 1464 KB |
| Title: | Multi-Layer LCP Technology for Millimetre Wave Applications |
| File Type: | Conference Paper |
| Issue: | Volume: System-on-Package (SoP) Wireless Components Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 137 KB |
| Title: | Modeling and Analysis of a Dual-Band Dual-Polarization Radiator Using FEKO |
| Abstract: | A dual-band hybrid antenna element comprising of microstrip and waveguide radiating elements is theoretically investigated through computer simulations. The low band radiator is a Shorted Annular Ring (SAR) microstrip antenna and the high band antenna is an open ended circular waveguide. First, the characteristics of a SAR patch antenna are presented and reviewed. Then the dual-band antenna configuration is described, which is realized by forming a waveguide radiator in the shorted region of the SAR microstrip antenna. Modeling and analysis of the SAR patch antenna and the hybrid element are investigated using the method-of-moment-based software package FEKO. The analysis includes return loss computations showing the element bandwidth at different frequency bands and the radiation patterns in the E- and H- planes. Feeding the element in phase quadrature produces circular polarizations (CP). The radiation patterns of the CP dual-band element are also analyzed using FEKO and the axial ratio performance is subsequently assessed |
| Author(s): | Amir I. Zaghloul, C. Babu Ravipati, M. T. Kawser, Amir I. Zaghloul, C. Babu Ravipati, M. T. Kawser |
| File Type: | Journal Paper |
| Issue: | Volume: 22 Number: 1 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 617 KB |
| Title: | Metamaterial Enhanced Antenna Systems: A Review |
| File Type: | Conference Paper |
| Issue: | Volume: S08 Design, Analysis and Applications of EM Metasurfaces I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 415 KB |
| Title: | MERCURY MOM: An Applied RWG EM Scattering Code for Electrically Large Bodies |
| File Type: | Conference Paper |
| Issue: | Volume: 30 Years of RWG Basis Functions Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 99 KB |
| Title: | Inverse Scattering and Information Management – Trends and Envisaged Strategies |
| File Type: | Conference Paper |
| Issue: | Volume: 4-MP-5 Inverse Scattering - Theory, Methods and Applications I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 254 KB |
| Title: | Introduction to Genetic Algorithms in Electromagnetics |
| Abstract: | This special issue of the ACES Journal is devoted to nev developments in Genetic Algorithm (GA) applications in computational electromagnetics. Genetic Algorithms have become extremely popular in the computational electromagnetics literature. The papers included in this special issue are very arcane, so I decided to include an unreviewed tutorial overview at the last minute as an introduction for those of you who are at a more basic level. GAs model natural selection and genetics on a computer to optimize a wide range of problems. |
| Author(s): | Randy L. Haupt, Randy L. Haupt |
| File Type: | Journal Paper |
| Issue: | Volume: 15 Number: 2 Year: 2000 |
| Download Link: | Click here to download PDF File Size: 2442 KB |
| Title: | Higher-order (LT/QN) vector finite elements for waveguide analysis |
| Abstract: | The finite element (FE) formulation for waveguide discontinuity analysis is reviewed and extended to multiple, arbitrarily-oriented ports. Several higher-order vector elements - specifically hierarchal linear tangential/quadratic normal (LT/QN) - are compared, and the extensions required to incorporate LT/QN elements in the formulation are presented. The improved accuracy afforded by LT/QN elements compared to constant tangential/linear normal (CT/LN) elements is investigated by considering energy conservation in an empty waveguide. Results obtained using both CT/LN and LT/QN elements are also shown for a problem of engineering interest: an E-plane bend. Results for the LT/QN elements compare especially well to approximate analytical results using quite coarse meshes. The paper concludes with a discussion of the use of iterative solvers and possible convergence problems encountered when using higher-order elements. |
| Author(s): | David B Davidson, David B Davidson |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 1 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 152 KB |
| Title: | Genetic Algorithm Applications for Phased Arrays |
| Abstract: | Abstract—Analytical approaches to phased array optimization started in the mid 1940s and transitioned to numerical techniques that can find a local minimum. Computers spurred the development of many different local optimization algorithms that worked well for a few variables and a cost function with a single minimum. In the 1990s, the genetic algorithm (GA) emerged as a competent optimization algorithm for a wide range of complex cost functions. This paper reviews phased array optimization and lays the foundation for the use of the GA. An extensive reference list is provided and some future research areas are discussed. |
| Author(s): | R. L. Haupt, R. L. Haupt |
| File Type: | Journal Paper |
| Issue: | Volume: 21 Number: 3 Year: 2006 |
| Download Link: | Click here to download PDF File Size: 340 KB |
| Title: | GA-MoM Optimization of Slot Arrays |
| File Type: | Conference Paper |
| Issue: | Volume: S33 Electromagnetic Simulation for RF and Microwave Design Optimization Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 447 KB |
| Title: | Fundamental Limitations on the Use of Open-Region Boundary Conditions and Matched Layers to Solve the Problem of Gratings in Metallic Screens |
| Abstract: | Interest in accurate modeling of the electromagnetic wave scattering from grating surfaces has been renewed due to recent advances in the manipulation and localization of the light in novel application of plasmonic resonance. This work briefly reviews the frequency-domain finite methods that have been used extensively to solve the grating problem. Emphasis will be placed on the finite methods that use local boundary operators or matched layers to truncate the computational boundary. It is shown that significant errors can be generated when using either of these two mesh truncation techniques even if the truncation boundaries are receded to avoid any evanescent waves emanating from the gratings. To quantify the error, the solutions obtained using the boundary condition or matched layers are compared to the solutions obtained using either mode matching or the surface integral equation method, both of which are devoid of truncation boundary related approximations and errors. Additionally, limitations on the use of the periodic boundary condition to truncate the mesh for periodic problems are also addressed. |
| Author(s): | B. Alavikia, O. M. Ramahi |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 8 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 1492 KB |
| Title: | Flammer’s Exact Solution for the Circular Conducting Disk: A Benchmark Problem for EM Software Validation |
| File Type: | Conference Paper |
| Issue: | Volume: S03 Computational Electromagnetics, Advanced Algorithms and Emerging Applications Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 319 KB |
| Title: | FINITE ELEMENTS IN ELECTROMAGNETICS: A JUBILEE REVIEW |
| Abstract: | This review describes the historical origins and the present state of the finite element method in electromagnetics. The foundation principles of finite elements are briefly reviewed. Applications are mainly to two and three dimensional problems of microwave and optical structures. The major types of scalar element are noted, and edge-interpolative vector elements are reviewed, firstly for the waveguide problem and then in three dimensions. An extensive bibliography is given, particularly stressing review papers. [Vol. 9, No. 2 (1994), Special Issue on The Numerical Computation of Low Frequency Electromagnetic Fields, pp 10-24] |
| Author(s): | J. Brian Davies, Peter P. Silvester, J. Brian Davies, Peter P. Silvester |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 2 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 1459 KB |
| Title: | FDTD Modeling of Electromagnetic and Thermal Dosimetry in Human for Microwave Exposures |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Finite Difference Time Domain Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 111 KB |
| Title: | EVOLUTION OF A SUITE OF COMPUTATIONAL MODELING TOOLS FOR MOBILE TELEPHONE DOSIMETRY STUDIES AT THE UNIVERSITY OF BRADFORD, U.K. |
| Abstract: | The evolution of a set of software and skills for the computational simulation of the interaction of mobile telephones with the human body is reviewed. These have been developed and applied in the authors' research group over the past decade. The work has aimed at maximization of realism in the representation of the body components and the telephone through use of MRI images, use of resolutions down to 1mm, incorporation of a hand into the model, development of a rotation algorithm for the telephone, development of techniques for modeling helical antennas, and development of hybrid techniques to allow the Method of Moments to be used to model the telephone, combined with finite difference methods for the human tissues. Generic experience and specimen results are presented. It is argued that the policy of pursuing realism in the simulation, beyond the level that is sufficient on physical grounds, is essential to convince the non-specialist public of the trustworthiness of the work. |
| Author(s): | Peter S. Excell, John A. Vaul, Peter S. Excell, John A. Vaul |
| File Type: | Journal Paper |
| Issue: | Volume: 16 Number: 2 Year: 2001 |
| Download Link: | Click here to download PDF File Size: 1082 KB |
| Title: | Estimation of Mutual Coupling in Irregular Planar Arrays |
| File Type: | Conference Paper |
| Issue: | Volume: S14 Numerical Methods for Analysis, Design and Measurement of Antennas I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 755 KB |
| Title: | Energy Paradigms of Augmented Tags for the Internet of Things Deployment |
| File Type: | Conference Paper |
| Issue: | Volume: S33 Electromagnetic Techniques for the Internet of Things I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 312 KB |
| Title: | EMX: Overcoming Silicon Chip EM Simulation Challenges for Passive Circuit Analysis and Model Development |
| File Type: | Conference Paper |
| Issue: | Volume: S23 Electromagnetic Modeling for Electronic Design Automation Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 405 KB |
| Title: | Electromagnetic Stimuli in Therapeutics and Resuscitation |
| File Type: | Conference Paper |
| Issue: | Volume: S53 Biological Effects of Electric, Magnetic and Electromagnetic Fields I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 428 KB |
| Title: | Electromagnetic Diffraction Modeling: High Frequency Asymptotics vs. Numerical Techniques |
| Abstract: | Electromagnetic diffraction modelling and recent numerical simulation approaches, on the canonical 2D non-penetrable wedge scattering problem, are reviewed in this introduction paper. |
| Author(s): | L. Sevgi |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 7 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 2024 KB |
| Title: | Development of Wideband L-Probe Coupled Patch Antenna |
| Abstract: | The patch antenna fed by an L-shaped probe was proposed in 1998. This feeding method, and its modified version, the meandering strip, has led to the development of a new class of wideband patch antennas which can be operated in linear, circular or dual polarization with excellent performance characteristics. L-probe coupled patch antennas are simple in structure and low in material and production costs. Moreover, it can be designed with dual wideband performance which is very attractive for modern mobile communications. This paper presents a review of the general designs for linearly and circularly polarized L-probe patch antennas. Comparisons between measured and simulated results are presented. Methods for gain enhancement and cross polarization suppression are also introduced. The designs and performances of two dual-band wideband L-probe fed patch antennas are also described. |
| Author(s): | Kwai Man Luk, Kai Fong Lee, Hau Wah Lai, Kwai Man Luk, Kai Fong Lee, Hau Wah Lai |
| File Type: | Journal Paper |
| Issue: | Volume: 22 Number: 1 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 546 KB |
| Title: | Development of the Incremental IEMF Method as an Analycital Proof for the Validity of FARS (Far-field Analysis of Radiation Sources) |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Integral Equation Based Techniques II Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 283 KB |
| Title: | Detect and Pointing Algorithm's Performance for a Planar Smart Antenna Array: A Review |
| Abstract: | An adaptive antenna array combines the signal of each element, using some constraints to produce the radiation pattern of the antenna, while maximizing the performance of the system. Direction of arrival (DOA) algorithms are applied to determine the directions of impinging signals, whereas beamforming techniques are employed to determine the appropriate weights for the array elements, to create the desired pattern. In this paper, a detailed analysis of both categories of algorithms is made, when a planar antenna array is used. Several simulation results show that it is possible to point an antenna array in a desired direction based on the DOA estimation and on the beamforming algorithms. A comparison of the performance in terms of runtime and accuracy of the used algorithms is made. These characteristics are dependent on the SNR of the incoming signal. |
| Author(s): | T. Varum, J. N. Matos, P. Pinho |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 8 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 3692 KB |
| Title: | Coupled EM-Structural Analysis in Convected Coordinates |
| File Type: | Conference Paper |
| Issue: | Volume: S47 Integral Equation Solvers for Real-Life Applications I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 226 KB |
| Title: | COMPUTER-BASED ELECTROMAGNETlC EDUCATION |
| Abstract: | Computers provide an exciting opportunity for boosting electromagnetic education and corporate training. Animated graphics of the wave propagation phenomenon, visualization of the abstract and highly mathematical subjects, one-on-one and self-paced tutoring, and the ability to mimic often unavailable and expensive laboratory experiments are among the often-cited benefits of a computer-based electromagnetic education. In this paper, we review the activities of the NSF/IEEE Center for Computer Applications in Electromagnetic Education (CAEME). This Center was established to stimulate and accelerate the use of computers and software tools in EM education. A reflection on the extensive software package developed and distributed by the CAEME Center is described and examples of the developed software are presented. To help integrate available EM software in classroom teaching and corporate training, CAEME developed four multimedia lessons for instruction. These interactive media lessons integrate and allow individuals to interactively manipulate information from multimedia sources such as video, software, and animated graphics and also include instructional information such as quizzes and tutorials to help evaluate the students' performance. Features of these lessons are presented, and future developments in the Center's activities are described. [Vol. 8, No. 1, (1993), Special Issue on Computer Applications in Electromagnetics Education, pp 77-107] |
| Author(s): | Magdy F. Iskander, Magdy F. Iskander |
| File Type: | Journal Paper |
| Issue: | Volume: 8 Number: 1 Year: 1993 |
| Download Link: | Click here to download PDF File Size: 4497 KB |
| Title: | Computational Electromagnetics for the Evaluation of EMC Issues in Multi-Component Energy Systems |
| Abstract: | This paper reviews the physics based modeling based on the electromagnetic stray fields and interference in the electric power network. The low frequency as well as high frequency equivalent source modeling of the power components for the study of radiated and conducted electromagnetic compatibility were implemented. The 3-D finite element analysis with some modification were applied in the solution method, as well as meshing strategies for the simulation of large scale components. Moreover, the stray field of the components was utilized for improving the control of the machine-drive system using hardware in loop method. The optimization in the design of the components such as the power converter based on the EMC compliance was also applied. This was achieved by coupling MATLAB with 3-D finite element technique for applying the numerical optimization techniques. The results were verified experimentally. |
| Author(s): | M. R. Barzegaran, O. A. Mohammed |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 12 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 3709 KB |
| Title: | COMPUTATION OF MULTIPOLE MOMENTS FOR SHORT THIN WIRE CHIRAL STRUCTURES |
| Abstract: | This paper considers the computation of the multipole moments of small chiral wire structures. The multipole moments are reviewed and it is shown that the charge induced on the wire must be accurately computed. A quasistatic thin-wire Galerkin Method of Moments formulation has been developed to numerically compute the charge distribution. The chiral structures under consideration are on the borderline of "thin" and a Body of Revolution Method of Moments formulation has also been developed for use as a check on the accuracy of the thin-wire approximations. It is shown that the "standard" thin-wire formulation is not sufficiently accurate, but the relatively simple addition of an end-cap greatly improves the convergence and accuracy of the formulation with acceptable computation cost. Finally, the formulation is extended to include bent wires, permitting the electric and magnetic dipole moments as well as the electric quadrupole moment to be calculated for a small chiral structure. [Vol. 10, No. 3 (1995), Special Issue on Advances in the Application of Method of Moments to Electromagnetic Radiation and Scattering Problems, pp 129-138] |
| Author(s): | Isak Petrus Theron, David Bruce Davidson, Johannes Hendrik Cloete, Isak Petrus Theron, David Bruce Davidson, Johannes Hendrik Cloete |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 3 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 905 KB |
| Title: | Compressive Processing for Computational Electromagnetics – Theoretical Basics, Current Trends and Advances |
| File Type: | Conference Paper |
| Issue: | Volume: 7-TA-5 Compressive Sensing in Applied Computational Electromagnetics - Trends and Advances Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 591 KB |
| Title: | Comparison and Analyzing of Propagation Models with Respect to Material, Environmental and Wave Properties |
| Abstract: | This paper presents a study on a class of algorithms based on Uniform Theory of Diffraction (UTD) for multiple diffractions. Within this context Slope UTD with Convex Hull (S-UTD-CH) model based on Slope UTD and Fresnel zone concept was reviewed. S-UTD-CH model can be used for fast and more accurate field prediction for multiple diffractions in transition zone. An extensive simulation results for comparison of UTD based algorithms with respect to the computation time and accuracy was provided. Furthermore, the study shows how relative permittivity constant, conductivity and inner angle of wedge and polarization type affect the relative path loss. |
| Author(s): | M. B. Tabakcioglu, D. Ayberkin, A. Cansiz |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 424 KB |
| Title: | Comparative Study on Improved and Traditional Equivalent Circuit of Long Primary Double-Sided Linear Induction Motor |
| Abstract: | Based on the quasi-two-dimensional (2D) field model of long primary double-sided linear induction motor (LPDLIM), an improved equivalent circuit model is proposed. First, the traditional equivalent circuit of LPDLIM is reviewed. Second, the skin effect correction coefficients for the secondary equivalent resistance and excitation reactance, and the secondary leakage inductance are derived. Moreover, an improved equivalent circuit model for LPDLIMs is presented, in which the leakage reactance of the secondary is considered, and the excitation reactance and secondary resistance are modified by the correction coefficients independently. Then, the slip frequency characteristics of various effect forces and variations of forces under different operations and mechanical air gap width are presented. Finally, the calculated forces by the proposed equivalent circuit are validated by the finite element method results and also compared with that of the traditional equivalent circuit model. |
| Author(s): | Q. Zhang, H.-J. Liu, Z.-Y. Zhang, T.-F. Song, Y. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 11 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1780 KB |
| Title: | Cloud Computing Simulation Tools for Nanophotonics at nanoHUB.org |
| File Type: | Conference Paper |
| Issue: | Volume: Computational Nanophotonics: Time – Domain Multiphysics, Meshless Methods and Non – Linear Optics Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 413 KB |
| Title: | Cloud Computing for the Science of Light: Nanophotonics Tools at nanoHUB.org |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling of Metamaterials and Transformation Based Devices Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 4202 KB |
| Title: | Characterization of a Planar Two-Arm Self-Complementary Square Spiral Antenna Using the Numerical Electromagnetics Code (NEC) |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic-Simulation-Driven-Design: Modeling and Optimization Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 604 KB |
| Title: | Characteristic Basis Function Method (CBFM)—An Iteration-free Domain Decomposition Approach in Computational Electromagnetics |
| Abstract: | In this paper we review a novel Domain Decomposition (DD) approach, called the Characteristic Basis Function Method (CBFM), which tackles large-scale electromagnetic problems by generalizing the concept of principle of localization that forms the cornerstone of asymptotic methods. The paper shows that the problem of having to deal with large matrices that arise in the conventional formulation of large problems with the Method of Moments (MoM) can be obviated, by dividing the original large problem into a number of smaller sub-problems that are more manageable to handle. However, unlike the conventional DD approaches that typically rely upon iteration algorithms to account for the inter-coupling between the subdomains, the CBFM tackles the problem with direct solvers instead. It is possible to do this in the context of CBFM, because it reduces the original large system matrix into one whose size is orders of magnitude smaller, and is appropriately called the “reduced matrix.” Furthermore, an important salutary feature of CBFM is that the algorithm is naturally parallelizable, an attribute that distinguishes it from many other CEM solvers, and makes it well suited for parallel platforms that have become ubiquitous in recent years. This, in turn, enables us to take advantage of the power of these platforms and to solve, numerically efficiently, large problems that were well beyond our reach in the past. The paper also shows that the basic concepts of CBFM are quite general, and they not only apply to MoM, but can also be tailored for both FEM and FDTD. Index Terms─ Characteristic Basis Function Method (CBFM), Domain Decomposition, Method of Moments (MoM), Finite element Method (FEM), Finite Difference Time Domain (FDTD). |
| Author(s): | R. Mittra |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 2 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 1733 KB |
| Title: | Calculator of WPT Efficiency between Transmitting and Receiving Elements |
| File Type: | Conference Paper |
| Issue: | Volume: 1-3-D Wireless Power Transfer Supported by Computational Electromagnetics Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 530 KB |
| Title: | Beam Scanning Reflectarray Antennas: A Technical Review |
| File Type: | Conference Paper |
| Issue: | Volume: Student Paper Competition Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 52 KB |
| Title: | Beam Scanning Reflectarray Antennas: A Technical Review |
| File Type: | Conference Paper |
| Issue: | Volume: Latest Developments of Reflect/Transmit Array Antennas Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 52 KB |
| Title: | Avoiding the Time-static Simplification in the Simulation of Time-varying Materials |
| File Type: | Conference Paper |
| Issue: | Volume: S07 Advances in Electromagnetics of Complex Media and Metamaterials - I Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 637 KB |
| Title: | Artificial Intelligence Technology and Engineering Applications |
| Abstract: | There has been sixty-year development of the artificial intelligence (AI) and the maturation of AI techniques is now leading to extensive applications and industrialization. In this paper, authors review the connotation and evolution of AI techniques and engineering applications. A four-layer framework of the AI technology system is summarized in this paper to help readers understand AI family. Engineering applications of AI techniques have made remarkable progress in the recent years, for instance, applications in fault diagnosis, medical engineering, petroleum industry and aerospace industry. By introducing the state-of-the-art of AI technologies, it can help the researchers in both engineering and science fields get ideas on how to apply AI techniques to solve application-related problems in their own research areas. |
| Author(s): | X. Li, H. Jiang |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 5 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1659 KB |
| Title: | Application of the Radial Point Interpolation Method as Meshless Time-Domain Technique in Electromagnetics |
| File Type: | Conference Paper |
| Issue: | Volume: Student Paper Competition Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 0 KB |
| Title: | Application of the Radial Point Interpolation Method as Meshless Time-Domain Technique in Electromagnetics |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Developments and Applications with Time-domain Modeling Techniques Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 3213 KB |
| Title: | APPLICATION OF NUMERICAL MODELING TECHNIQUES IN ELECTROMAGNETIC HYPERTHERMIA |
| Abstract: | Electromagnetic hyperthermia has been demonstrated to be a safe and useful adjuvant to ionizing radiation in the treatment of malignant tumors. However, applicators and systems for delivering the optimum treatment prescribed by the physicians are far from being available at present. Computer modeling can play a significant role in the design of better heating equipment and in improving the quality of the hyperthermia treatments currently being administered. There is an active ongoing research to develop suitable calculational models using a variety of numerical techniques. But several gaps exist in the current knowledge regarding the validity of these numerical simulations in the clinical context. The development of treatment planning systems similar to those used for radiation therapy requires resolution of these issues. Of the different numerical modeling approaches currently being developed, the finite-difference time-domain (FD-TD) technique has been extensively applied to calculate specific absorption rate (SAR) patterns in complex 3-D heterogeneous biological objects primarily because it is accurate and has a small computer burden relative to frequency-domain integral equation and finite element techniques. Following a brief review of the historical development of numerical modeling of electromagnetic interaction with biological structures in the hyperthermia context, examples of recent calculations using FD-TD technique in realistic situations in electromagnetic hyperthermia are provided. It has been observed from 2-D calculations, that the water bolus, routinely used in the clinic to provide energy coupling and surface (skin) temperature control, and the inhomogeneous tissue structures significantly modify the SAR patterns compared to patterns computed in planar and homogeneous structures. In conclusion, future areas of work are identified and discussed. [Vol. 7, No. 2, pp. 61-71 (1992), Special lssue on Bioelectromagnetic Computations] |
| Author(s): | V. Sathiaseelan, A. Taflovel, M.J. Picket-Mayl, C. Reuterl, B. B. Mittal, V. Sathiaseelan, A. Taflovel, M.J. Picket-Mayl, C. Reuterl, B. B. Mittal |
| File Type: | Journal Paper |
| Issue: | Volume: 7 Number: 2 Year: 1992 |
| Download Link: | Click here to download PDF File Size: 945 KB |
| Title: | Antennas Wrapped up on Slender Column |
| File Type: | Conference Paper |
| Issue: | Volume: S24 Mobile and Small Antennas I Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 332 KB |
| Title: | Antenna Developments for Military Applications |
| Abstract: | A review of current, past and projected activities in antenna development indicates a broad spectrum of requirements, and subsequently a variety of innovations to meet these requirements for military radar and communications systems. Designing the antennas in the operating environment, known as in-situ design, is an important factor in guaranteeing the successful operation of the antenna in the field. This paper presents the basic blocks in antenna development, followed by examples of some antennas developed at the Army Research Laboratory for military systems and applications. These include Rotman lenses as beam formers for electronically scanning arrays; phased arrays using MEMS phase shifters at 30 GHz; a 76-GHz narrow beam, low-sidelobe antenna for collision avoidance radar; and other specialized antennas. Of special interest is an effort on developing and using metamaterials in antenna designs, where practical realizations of such materials have the potential of improving the performance and reducing the size of antennas. |
| Author(s): | A. I. Zaghloul, S. J. Weiss, W. K. Coburn |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 1 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 1198 KB |
| Title: | Anonymous Peer review. Time to Move on? |
| File Type: | Newsletter Paper |
| Issue: | Volume: 22 Number: 1 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 115 KB |
| Title: | Analytical Approximations for the Maximum-to-mean Ratio of the E-field in a Reverberation Chamber: A Review |
| Abstract: | The expected value of the maximum value of the rectangular E-field is important in radiated susceptibility testing in a reverberation chamber. In this paper, different forms of equations for the maximum-to-mean ratio of the rectangular E-field are reviewed. Important derivations are summarized and detailed. It is interesting to note that some series which could be difficult to deal with from mathematics could be solved efficiently from physical point of view. The relationship between the independent sample number N and the parameters in generalized extreme value distribution is also given. |
| Author(s): | Q. Xu, R. Jia, L. Geng, H. Guo, Y. Zhao |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 8 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 1349 KB |
| Title: | An Overview of Equivalent Circuit Modeling Techniques of Frequency Selective Surfaces and Metasurfaces |
| Abstract: | Circuit analysis of frequency selective surfaces is reviewed with the aim to underline range of validity of different models and their advantages in terms of simplicity and physical insight. The circuit approach is based on an equivalent representation of the FSSs with series or shunt connections of inductances and capacitances. Dense non-resonant periodic surfaces (i.e.: grid or patch arrays) can be analyzed analytically by computing the values of inductors or capacitors via the homogenization theory. As the lattice period increases with respect to the operating wavelength or the element shape becomes resonant, a fully analytical circuital approach fails, in particular, in the presence of thin substrates. However, simple circuit approaches can still be employed by deriving lumped parameters values via a quick pre-processing and then generalizing them. The results are accurate up to the resonant frequency region of the element. By including an additional lumped element it is possible, taking into account the effect of the first high order Floquet harmonic. The multi-mode formulation is also able to catch the highly nonlinear response of FSS screens in the grating lobe region provided that the current profile of the element does not change significantly. |
| Author(s): | F. Costa, A. Monorchio, G. Manara |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 12 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1301 KB |
| Title: | An Incomplete Review of Fast Multipole Methods–from Static to Wideband–as Applied to Problems in Computational Electromagnetics |
| Abstract: | Fast multipole methods (FMM) and their immediate predecessors, tree codes, were developed in response to the need for solving Nbody problems that occur in applications as varied as biophysics, computational chemistry, astrophysics and electromagnetics. In all these areas, it is necessary to compute long range potentials of the form 1/R between a dense distribution of point charges, where R is the distance between any two charges. Often, repeated evaluation of these potentials is necessary. It is apparent that the cost of direct evaluation, which scales as O(N2) for N degrees of freedom, forms a fundamental bottleneck. FMM and tree methods ameliorate the cost associated with these computation; CPU times of these method scale as O(N). It stands to reason that FMM has had a seminal impact on a multitude of fields, so much so, that it was recognized as one of the top ten algorithms of the past century. A method to rapidly compute potentials of the form e-j κR/R soon followed. As the reader is aware, these potentials are the crux of integral equation based analysis tools in electromagnetics and the advent of these methods have transformed the face of computational electromagnetics. Consequently, the state of art of integral equation solvers has grown by leaps and bounds over the past decade. This paper attempts to present a detailed review of the state of art of FMM based methods that are used in computational electromagnetics, from the static to the high frequency regime. |
| Author(s): | M. Vikram, B. Shanker |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 2 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 889 KB |
| Title: | Advances of Neural Network Modeling Methods for RF/Microwave Applications |
| Abstract: | Abstract: This paper provides an overview of recent advances of neural network modeling techniques which are very useful for RF/microwave modeling and design. First, we review neural network inverse modeling method for fast microwave design. Conventionally, design parameters are obtained using optimization techniques by multiple evaluations of EM-based models, which take a long time. To avoid this problem, neural network inverse models are developed in a special way, such that they provide design parameters quickly for a given specification. The method is used to design complex waveguide dual mode filters and design parameters are obtained faster than the conventional EM-based technique while retaining comparable accuracy. We also review recurrent neural network (RNN) and dynamic neural network (DNN) methods. Both RNN and DNN structures have the dynamic modeling capabilities and can be trained to learn the analog nonlinear behaviors of the original microwave circuits from input-output dynamic signals. The trained neural networks become fast and accurate behavioral models that can be subsequently used in systemlevel simulation and design replacing the CPUintensive detailed representations. Examples of amplifier and mixer behavioral modeling using the neural-network-based approach are also presented. |
| Author(s): | H. Kabir, Y. Cao, Y. Cao, Q. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 5 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 343 KB |
| Title: | Advances in the Adjoint Variable Method for Time-Domain Transmission Line Modeling |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Time Domain Techniques Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 0 KB |
| Title: | Advances in the Adjoint Variable Method for Time-Domain Transmission Line Modeling |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Time Domain Techniques Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 82 KB |
| Title: | Advanced Modeling of Characteristic Mode Theory for Antenna Applications |
| File Type: | Conference Paper |
| Issue: | Volume: 2-1-A Brainstorm for Computational Electromagnetics: What We Have Achieved and What We Will Do I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 473 KB |
| Title: | Active Millimeter Wave Imaging System with Sparse Antenna Array |
| File Type: | Conference Paper |
| Issue: | Volume: 2-4-D Millimeter Wave/THz Imaging I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 409 KB |
| Title: | Active Metamaterial Incorporating Gain Device/Medium: A Review |
| Abstract: | Metamaterials intrigue many exciting applications in the broad electromagnetic spectrum ranging from microwave to optics. However, many of the envisaged applications still remain in theory, largely because of the intrinsic loss and dispersion associated with passive metamaterials. Incorporating active devices or media into conventional passive metamaterial structures for loss compensation, as well as dispersion control, is very attractive and may finally enable many desired applications. In addition, because of the added design degree of freedom in active metamaterials, new and rich physical phenomena and insights can be discovered. In this paper, we review the recent progress in the realm of active, gain-assisted metamaterials. Physical limitations on loss and bandwidth of metamaterials are firstly discussed. Recent experimental efforts in transmission-line and volumetric metamaterials with net gain in the microwave and optical regime are then examined. The idea of utilizing non-Foster active devices to reduce the dispersion and achieve broad bandwidth is also presented. Finally, one of the important issues of active metamaterial design, stability, is briefly discussed. |
| Author(s): | Q. Tang, H. Xin |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 12 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 975 KB |
| Title: | A VOLUME INTEGRAL CODE FOR EDDY-CURRENT NONDESTRUCTIVE EVALUATION |
| Abstract: | This paper is an extension of J. R. Bowler, H. A. Sabbagh, and L. D. Sabbagh, "A Computational Model of Eddy-Current Probes Over a Stratified Composite Workpiece," which was presented at the 4th Annual Review of Progress in Applied Computational Electromagnetics, Monterey, CA, March 1988. It describes an application of modern methods of computational electromagnetics to the problem of eddy-current nondestructive evaluation (NDE). Specifically, a volume integral equation is developed that can be used to model eddy-current probes with ferrite cores, or it can be used to compute flaw-field interactions. Both of these problems are of considerable importance in applying electromagnetic techniques to NDE, for they are intimately involved in detecting flaws, and inverting eddy-current data for reconstructing flaws. The model is fully three-dimensional, and the discretized integral equation is solved iteratively using conjugate gradients and FFT techniques. Problems with 12,000 unknowns are being routinely solved on the Alliant FX/ 1 minisupercomputer in reasonable times. The model is used to compute such important probe parameters as impedance and coupling. It is also used to compute the electromagnetic response of flaws as the geometry of the flaw changes, or as a function of frequency. [Vol. 4, No. 1, pp.3-22 (1989)] |
| Author(s): | Harold A. Sabbagh, John R. Bowler, L. David Sabbagh, Harold A. Sabbagh, John R. Bowler, L. David Sabbagh |
| File Type: | Journal Paper |
| Issue: | Volume: 4 Number: 1 Year: 1989 |
| Download Link: | Click here to download PDF File Size: 762 KB |
| Title: | A Uniaxial Time-Domain Wave Potential Analysis of the Electromagnetic Field in Nonuniform Media |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Computational Techniques for System Design Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 97 KB |
| Title: | A Summary Review on 25 Years of Progress and Future Challenges in FDTD and FETD Techniques |
| Abstract: | The finite-difference time-domain (FDTD) method has established itself among the most popular methods for the numerical solution of Maxwell equations. Reasons for its popularity include its versatility, matrix-free characteristic, ease for parallelization, and low computational complexity. In recent years, the finite-element time-domain (FETD) has also become another very popular algorithm for solving time-domain Maxwell equations due to its geometrical flexibility and the steady growth in hardware computing power. In this review, we succinctly recollect some of the milestones in the development of FDTD and FETD over the last 25 years, and briefly discuss some challenges for the future development of these two algorithms. |
| Author(s): | F. L. Teixeira |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 1 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 274 KB |
| Title: | A ROMANIAN EXPERIENCE IN COMPUTER-AIDED ELECTROMAGNETIC EDUCATION |
| Abstract: | The paper presents the actual interests in computer-aided electromagnetic education (CAEE) at the Electrical Engineering Department from Polytechnic Institute of Bucharest, Romania. The actual state of computer use on different levels of undergraduate and graduate education is presented. Specifically, an overview of the undergraduate theoretical training and practical applications is described, and research topics for graduate reports and doctoral dissertations are discussed. Issues related to hardware utilities are reviewed, and future projects aimed at improving the CAEE capabilities in Romania are described. The material is based on significant selected references. [Vol. 8, No. 1, (1993), Special Issue on Computer Applications in Electromagnetics Education, pp 125-137] |
| Author(s): | Mihaela Morega, Daniel Ioan, Mihaela Morega, Daniel Ioan |
| File Type: | Journal Paper |
| Issue: | Volume: 8 Number: 1 Year: 1993 |
| Download Link: | Click here to download PDF File Size: 748 KB |
| Title: | A Review of Ultra-Wideband Array Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: 7-TA-4 In Celebration of 70th Birthday of Prof. Jia-dong Xu I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 132 KB |
| Title: | A Review of the Modal Decomposition Matrix for Calculating the Far Field of an Infinitely Flanged Rectangular Waveguide |
| Abstract: | We determine the radiation from an infinitely flanged rectangular waveguide using the modal decomposition matrix (MDM) method. The MDM method computes the electromagnetic field components at the aperture in the Fourier domain by representing the radiated field in terms of a sampling of the free-space transverse wave number. The results of the MDM approach show good agreement with numerical approaches using commercial electromagnetic modeling software. |
| Author(s): | G. A. Mitchell, W. Wasykiwskyj |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 12 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1843 KB |
| Title: | A Review of Terahertz Imaging Systems in CMOS |
| File Type: | Conference Paper |
| Issue: | Volume: 3-2-D EM + Active Device Modeling for MMIC and 5G Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 175 KB |
| Title: | A Review of Statistical Methods for Comparing Two Data Sets |
| Abstract: | Statistical approaches to compare data for validation of computational electromagnetics have been used for several years. They provide an accepted means of obtaining a numerical value to quantify the data under consideration. However, the use and meaning of these ‘numbers’ depends, by necessity, on the application. This paper provides an overview of some of the most widely applicable techniques, relating the output of these to visual assessment. It further includes comparison with the FSV (Feature Selective Validation) method allowing a triangulation between statistical approaches, visual approaches and heuristic approaches to validation. It is important that the decision to use or reject a particular technique for validation is based on a rational and objective selection approach. This paper suggests a framework to support this selection approach. |
| Author(s): | A. Duffy, A. Orlandi, A. Duffy, A. Orlandi |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 1 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 165 KB |
| Title: | A Review of Recent Advances in Designing True-Time-Delay Microwave Lenses Exploiting Metamaterials with Non-Resonant Constituting Unit Cells |
| Abstract: | This paper presents a review of recent developments in the design of planar microwave lenses capable of operating over broad bandwidths in a true-time-delay fashion. The lenses discussed in this paper consist of planar apertures populated with miniature, sub-wavelength time-delay units. Each time delay unit is the unit cell of an appropriately-designed Frequency Selective Surface (FSS) with non-resonant, sub-wavelength constituting unit cells and is designed to provide a constant time-delay unit over the frequency range at which the lens operates. Designs that exploit both band-pass and low-pass FSSs are presented and discussed. Because of the non-resonant nature of their constituting unit cells and their small dimensions, such lenses can operate over broad bandwidths with wide fields of views. When used in conjunction with appropriately designed feed antennas, these lenses can be used in multi-beam, high-gain, broadband antenna apertures. |
| Author(s): | N. Behdad |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 12 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1848 KB |
| Title: | A Review of Perfectly Matched Absorbers for the Finite-Volume Time-Domain Method |
| Abstract: | Different implementations of planar perfectly matched absorbers are studied under the unified framework of the Finite-Volume Time-Domain (FVTD) method. This comparative analysis allows to discuss the similarities existing between the theoretical models and explores the differences in their practical implementation and numerical performance in the framework of the FVTD method. Numerical experiments for performance analysis of the different PML models are conducted in terms of discretization and angle of incidence using waveguide models. The results are compared to theoretically expected values and to the first-order Silver M¨uller absorbing boundary condition. |
| Author(s): | T. Kaufmann, K. Sankaran, C. Fumeaux, R. Vahldieck, T. Kaufmann, K. Sankaran, C. Fumeaux, R. Vahldieck |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 3 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 318 KB |
| Title: | A Review of Path Integral Time Domain Method |
| File Type: | Newsletter Paper |
| Issue: | Volume: 19 Number: 3 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 570 KB |
| Title: | A Review of Advanced Characteristic Mode Theories for Complex Electromagnetic Problems |
| File Type: | Conference Paper |
| Issue: | Volume: 4-1-A Brainstorm for Computational Electromagnetics: What We Have Achieved and What We Will Do II Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 245 KB |
| Title: | A Review and Application of the Finite-Difference Time-Domain Algorithm Applied to the Schrodinger Equation |
| Abstract: | This paper contains a review of the FDTD algorithm as applied to the time-dependent Schrodinger equation, and the basic update equations are derived in their standard form. A simple absorbing boundary condition is formulated and shown to be effective with narrowband wave functions. The stability criterion is derived from a simple, novel perspective and found to give better efficiency than earlier attempts. Finally, the idea of probability current is introduced for the first time and shown how it can be used to radiate new probability into a simulation domain. This removes the need to define an initial-valued wave function, and the concept is demonstrated by measuring the transmission coefficient through a potential barrier. |
| Author(s): | J. R. Nagel |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 1 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 901 KB |
| Title: | A New Closed-Form Expression for Dispersion Characteristics of Fundamental Mode of SIW by Least Squares Method |
| Abstract: | A new and accurate closed-form expression is introduced using least squares method (LSM) to calculate propagation constant of substrate integrated waveguide (SIW) at its fundamental mode of operation. The derived equation is a function of geometrical parameters of the structure and accurately estimates cutoff frequency of the dominant mode. The LSM is used to determine the effective width of the SIW structure. A review and comparisons with recently published simulation and measurement results are also provided, which verify the accuracy of the proposed method. |
| Author(s): | M. GH. Alijani, M. H. Neshati |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 8 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 798 KB |
| Title: | 25 Years of Progress and Future Challenges in Integral Equation Solvers |
| File Type: | Conference Paper |
| Issue: | Volume: 25 Years of Progress and Future Challenges in Applied Computational Electromagnetics I Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 106 KB |
| Title: | 25 Years of Progress and Future Challenges in FDTD/FETD Techniques and Applications |
| File Type: | Conference Paper |
| Issue: | Volume: 25 Years of Progress and Future Challenges in Applied Computational Electromagnetics II Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 297 KB |
| Title: | 25 Years of Progress and Future Challenges in Boundary-Element Based Field-Circuit and Multiphysics Solvers |
| File Type: | Conference Paper |
| Issue: | Volume: 25 Years of Progress and Future Challenges in Applied Computational Electromagnetics II Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 629 KB |
| Title: | Using Time-domain Codes to Find RF Cavity Eigenmodes |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Finite Difference Time Domain Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 29 KB |
| Title: | Using the Best Uniform Approximation with Compression for Efficient Computation of Monostatic Scattering |
| Abstract: | The best uniform approximation method hybridized with Singular Value Decomposition (SVD) is proposed to reduce the time requirement for computation of monostatic Radar Cross Section (RCS). In contrast to our previous work, the traditional best uniform approximation technique is applied to compute the key excitation vectors instead of electric current vectors. Reduction of the number of multiple excitation vectors can lead to significantly reduced computation time. Furthermore, with low-rank property, the key excitation vectors could be further compressed by SVD, resulting in a more efficient method. Numerical results demonstrate that the proposed method is efficient for monostatic RCS calculation with high accuracy. |
| Author(s): | Z. Liu, S. He, X. Zhang, Y. Liu, Y. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 11 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 603 KB |
| Title: | Using System-Theoretical Consideration for Calculating Coupling Effects in Packages |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in CEM Applications I Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 421 KB |
| Title: | Using Superformula to Miniaturize CPW Rat Race Coupler |
| Abstract: | This paper proposes a new CPW rat race coupler whose shape has been meandered using the superformula for size reduction. The coupler operates at a center frequency of 1.8 GHz. The size reduction in the proposed design is about 74% as compared to conventional ring rat race coupler. The bandwidth of the proposed coupler defined by |S11| < -15 dB is about 31.6%. |
| Author(s): | A. A. Omar, N. I. Dib |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 12 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1901 KB |
| Title: | USING NONUNIFORM SEGMENTS LENGTHS WITH NEC TO ANALYZE ELECTRICALLY LONG WIRE ANTENNAS |
| Abstract: | In this paper an electrically long monopole is analyzed using the Numerical Electromagnetics Code, version two (NEC-2). Due to the electrical length of the monopole and the segment length requirement established for the NEC-2 program, the computer memory requirement and computational time become excessive. By successively increasing the segment length with distance from the source, very large structures can be analyzed accurately and efficiently. Various schemes for selecting the segment lengths are considered, and the results are compared to those obtained by using a large number of electrically short segments. This technique of grading segment lengths allows one to employ NEC-2 to analyze other electrically long wire antennas. [Vol. 5, No. 2, pp. 2-16 (l990)] |
| Author(s): | Saad N. Tabet, J. Patrick Donohoe, Clayborne D. Taylor, Saad N. Tabet, J. Patrick Donohoe, Clayborne D. Taylor |
| File Type: | Journal Paper |
| Issue: | Volume: 5 Number: 2 Year: 1990 |
| Download Link: | Click here to download PDF File Size: 689 KB |
| Title: | Using Near Field Equivalent Sources in Combination with Large Element Physical Optics to Model a Slant 45 Degree Omni Directional Antenna over Ground |
| File Type: | Conference Paper |
| Issue: | Volume: S03 EM Modeling using Feko/WinProp Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 426 KB |
| Title: | Using Near Field Equivalent Sources in Combination with Large Element Physical Optics to Model a Slant 45 Degree Omni Directional Antenna over Ground |
| Abstract: | This paper compares the theoretical and measured antenna patterns of a slant 45-degree antenna on a rolled edge ground plane. Advantages of using sampled nearfield currents in combination with large element physical optics in determining the reflected far fields will be described. |
| Author(s): | K. Snyder |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1397 KB |
| Title: | Using MATLAB’s Parallel Processing Toolbox for Multi-CPU and Multi-GPU Accelerated FDTD Simulations |
| Abstract: | MATLAB is a good testbed for prototyping new FDTD techniques as it provides quick programming, debugging and visualization capabilities compared to lower level languages such as C or FORTRAN. However, the major disadvantage of using MATLAB is its slow execution. For faster simulations, one should use other programming languages like Fortran or C with CUDA when utilizing graphics processing units. Development of simulation codes using these other programming languages is not as easy as when using MATLAB. Thus the main objective of this paper is to investigate ways to increase the throughput of a fully functional finite difference time domain method coded in MATLAB to be able to simulate practical problems with visualization capabilities in reasonable time. We present simple ways to improve the efficiency of MATLAB simulations using the parallel toolbox along with the multi-core central processing units (CPUs) or the multiple graphics processing units (GPUs). Native and simple MATLAB constructs with no external dependencies or libraries and no expensive or complicated hardware acceleration units are used in the present development. |
| Author(s): | A. J. Weiss, A. Z. Elsherbeni, V. Demir, M. F. Hadi |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 5 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1792 KB |
| Title: | Using MATLAB to Model Inhomogeneous Media in Commercial Computational Electromagnetics Software |
| Abstract: | This paper presents a new method to model inhomogeneous media in commercial electromagnetics software, especially FEKO. In this method, the inhomogeneous medium is fragmented to some homogeneous pieces. If the size of these pieces is chosen correctly, then the electromagnetic behaviors of them and inhomogeneous medium are the same. Since creating these homogeneous pieces in FEKO manually is very difficult and time consuming, MATLAB is employed to create these pieces in FEKO. |
| Author(s): | A. Farahbakhsh, D. Zarifi, A. Abdolali |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 9 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 511 KB |
| Title: | Using MATLAB to Control Commercial Computational Electromagnetics Software |
| Abstract: | This paper provides details on how to use MATLAB to control some commercial electromagnetics software packages. FEKO is an example that can be directly called from MATLAB. Other commercial software, such as CST Microwave Studio and Ansoft HFSS, require a scripting language interface. An example of a design of an inset rectangular patch antenna is presented using a direct call to FEKO and a Visual Basic for Applications interface to CST Microwave Studio are presented. |
| Author(s): | R. L. Haupt, R. L. Haupt |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 1 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 176 KB |
| Title: | Using Logo-Antenna Based RFID Tags forAdvertising |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling of RFID Devices and Systems Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 548 KB |
| Title: | NON-INVASIVE ACTIVE THERMOMETRY WITH A MICROWAVE TOMOGRAPHIC SCANNER IN HYPERTHERMIA TREATMENTS |
| Abstract: | In this work the active microwave tomographic imaging of tissue temperature changes induced in deep hyperthermia treatments is studied. The thermal images would allow to monitor and optimize the treatment, increasing its efficacy and avoiding the heating of healthy tissues. As some hyperthermia systems are based on a cylindrical geometry, it is possible to integrate a microwave imaging array in the same structure, providing a non-invasive tool for the monitoring and control. The application of this technique to deep hyperthermia treatments is investigated by numerical simulations and experimentally on two phantoms of thorax and pelvis, using a prototype for microwave tomography recently developed [Jofre et al, 1990]. lVol. 7, No. 2, pp. 121-127 (1992), Special Issue on Bioelectromagnetic Computations] |
| Author(s): | J. J. Mallorqui, A. Broquetas, L. Jofre, A. Cardama, J. J. Mallorqui, A. Broquetas, L. Jofre, A. Cardama |
| File Type: | Journal Paper |
| Issue: | Volume: 7 Number: 2 Year: 1992 |
| Download Link: | Click here to download PDF File Size: 4250 KB |
| Title: | COMPUTATIONAL METHOD FOR POWER LINE MAGNETIC FIELD EVALUATION |
| Abstract: | The paper reports a model for the power line magnetic field evaluation. The obtained results for three different power lines (380 kV double circuit,380 kV single circuit, 220 kV double circuit) was validated with measurement data. Calculated and corresponding measured data were found in good agreement. The influence of geometrical and electrical power line parameters, such as the spatial configuration of the conductors and line phase sequences, is evaluated and discussed. Data on the influence of adjacent line span on the field are also reported. The method can be used for prediction of human exposure in epidemiological studies. [Vol. 7, No. 2, pp. 148-161 (1992), Special Issue on Bioelectromagnetic Computations] |
| Author(s): | Santi Tofani, Giovanni d'Amore, Giancarlo Bonazzola, Giovanni Fiandino, Santi Tofani, Giovanni d'Amore, Giancarlo Bonazzola, Giovanni Fiandino |
| File Type: | Journal Paper |
| Issue: | Volume: 7 Number: 2 Year: 1992 |
| Download Link: | Click here to download PDF File Size: 740 KB |
| Title: | THE APPLICATION OF NESTED DISSECTION TO THE SOLUTION OF A 2.5D ELECTROMAGNETIC PROBLEM |
| Abstract: | We use the method of nested dissection to solve a 2.5D finite difference electromagnetic problem. This method is considered in some detail, and we have found that the expected theoretical run time savings over more common methods are realised in practice. The program has been used to model EM propagation in coal seams with a view to detecting seam disruptions, which can cause a loss of production in longwall mining operations. Various experimental results and a field survey are discussed and we are able to use these results to construct a physically reasonable model which explains the field data. Some further realistics geological structures are modelled and a comparison between our modelling program and several independent methods shows satisfactory agreement. |
| Author(s): | G. H. Smith, P. R. Williamson, K. Vozoff, G. H. Smith, P. R. Williamson, K. Vozoff |
| File Type: | Journal Paper |
| Issue: | Volume: 5 Number: 2 Year: 1990 |
| Download Link: | Click here to download PDF File Size: 1916 KB |
| Title: | FOUR-ELEMENT BEVERAGE ARRAY |
| Abstract: | An experimental four-element high-frequency Beverage antenna array has been devised for tests on medium range and long range ionospheric circuits. The radiation pattern of the experimental array was calculated using Numerical Electromagnetics Code (NEC) and found to be skewed in azimuth. The antenna installation was subsequently modified in accordance with NEC predictions and the desired beam direction was obtained. Measurements confirmed that the NEC predictions were valid. [Vol. 1, No. 1, pp. 15-20 (1986)] |
| Author(s): | D. V. Campbell, P. Cunningham, P. Dubowicz, K. Loffer, D. V. Campbell, P. Cunningham, P. Dubowicz, K. Loffer |
| File Type: | Journal Paper |
| Issue: | Volume: 1 Number: 1 Year: 1986 |
| Download Link: | Click here to download PDF File Size: 368 KB |
| Title: | The application of nested dissection to the solution of a 2.5D electromagnetic problem |
| Abstract: | We use the method of nested dissection to solve a 2.5D finite difference electromagnetic problem. This method is considered in some detail, and we have found that the expected theoretical run time savings over more common methods are realised in practice. The program has been used to model EM propagation in coal seams with a view to detecting seam disruptions, which can cause a loss of production in longwall mining operations. Various experimental results and a field survey are discuessed and we are able to use these results to construct a physically reasonable model which explanes the field data. Some further realistic geological structures are modelled and a comparison between out modelling program and several independent methods show satisfactory agreement. |
| Author(s): | G.H. Smith, P.R. Williamson, K. Vozoff, G.H. Smith, P.R. Williamson, K. Vozoff |
| File Type: | Journal Paper |
| Issue: | Volume: 15 Number: 2 Year: 2000 |
| Download Link: | Click here to download PDF File Size: 1193 KB |
| Title: | Linear Triangles versus Biquadratic Quadrangles in RCS computations |
| Abstract: | |
| Author(s): | A. Herschlein, J. von Hagen, D. Löffler, W. Wiesbeck, A. Herschlein, J. von Hagen, D. Löffler, W. Wiesbeck |
| File Type: | Journal Paper |
| Issue: | Volume: 20 Number: 3 Year: 2005 |
| Download Link: | Click here to download PDF File Size: 965 KB |
| Title: | Digital joint phase and sampling instant synchronisation for UMTS standard |
| File Type: | Conference Paper |
| Issue: | Volume: System Architectures and Analysis Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 187 KB |
| Title: | Characterizing Dispersion in the Enclosed-Space Radio Channel using a Composite Mode Model |
| File Type: | Conference Paper |
| Issue: | Volume: Propagation Channel Characterization Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 1434 KB |
| Title: | Deterministic Channel Modeling and Performance of Monopolarized and Multipolarized MIMO Wireless Channels |
| File Type: | Conference Paper |
| Issue: | Volume: MIMO and Diversity System Characterization Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 153 KB |
| Title: | Real Time Angle of Arrival Estimation for GSM Signals |
| File Type: | Conference Paper |
| Issue: | Volume: Direction of Arrival Estimation Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 553 KB |
| Title: | Active Frequency Selective Surfaces for Antenna Applications Electronically to Control Phase Distribution and Reflective/Transmissive Amplification |
| File Type: | Conference Paper |
| Issue: | Volume: Phased Array and Active Antennas Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 153 KB |
| Title: | Development of Time-Domain Surface Macromodels From Material Measurements |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced EMC Modeling Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 310 KB |
| Title: | Reduction of Sensitivity to Measurement Errors in the Derivation of Equivalent Models of Emission in Numerical Computation |
| Abstract: | In this paper, the accuracy of an equivalent dipole model for representing electromagnetic emissions from printed circuit boards (PCB) is studied. The optimization of nearfield measurement parameters and required PCB parameters for building a numerical model are discussed and their impact on the accuracy of emission predictions is examined. |
| Author(s): | X. Tong, D. W. P. Thomas, A. Nothofer, C. Christopoulos, P. Sewell |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 7 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 1205 KB |
| Title: | Non-linear Dielectrics and Ferrites in ICEPIC |
| File Type: | Conference Paper |
| Issue: | Volume: Multi-Physics Modeling and Simulations Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 679 KB |
| Title: | Application of the Sliding Surface Method with 3D Finite Element Analyses of a Hybrid Magnetic Bearing |
| File Type: | Conference Paper |
| Issue: | Volume: Low-Frequency Computational Electromagnetics Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 1451 KB |
| Title: | A Simplified Analytical Solution for Characterizing Edge Currents Along a Finite Ground Plane |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling and Simulation in Electromagnetic Engineering Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 1222 KB |
| Title: | Extended Scheme using Equivalent Dipoles for Characterizing Edge Currents Along a Finite Ground Plane |
| Abstract: | For the assessment of radiated fields, a simplified analytical solution that approximates the effects of the currents induced at the edges of a finite ground plane is presented. These edge currents are induced by the actual current sources on the plane. This method can be used in characterizing the electromagnetic (EM) emission from any practical PCB and avoids the need for using high-frequency techniques in evaluating effects due to diffraction. |
| Author(s): | C. Obiekezie, D. W. Thomas, A. Nothofer, S. Greedy, L. R. Arnaut, P. Sewell |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 11 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 465 KB |
| Title: | Convex Optimization Based Sidelobe Suppression for Adaptive Beamforming with Subarray Partition |
| Abstract: | This paper proposes a convex optimization based method to suppress sidelobe in adaptive beamforming at subarray level. Usually phase shift rather than amplitude tapering is implemented at element level to maximize signal to noise ratio. Nevertheless, sidelobe control can be realized at subarray level. The proposed approach is realized by adding a constraint minimizing the difference between weights at subarray level and element-level Chebyshev synthesis into the optimal conditions. Compared with penalty function method, simulations show that for a uniform linear array, the proposed method can suppress sidelobe level considerably, especially the lobes close to mainlobe. Furthermore, it is able to produce better shaped main lobe, which is extremely close to the referenced pattern. |
| Author(s): | S. Xiaofeng, X. Jia, Z. Ying, K. Ling |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 1 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 490 KB |
| Title: | A Transparent UWB Antenna with a 5 to 6 GHz Band Notch Using Two Split Ring Resonators |
| Abstract: | A miniaturized thin film transparent ultrawideband (UWB) antenna design with a band notch is presented. A pair of split-ring resonators (SRRs) is placed besides the radiating element to realize the band notch centered at 5.5 GHz. The proposed transparent antenna covers the whole 3.1 to 10.6 GHz UWB frequency band with a notch from 5 to 6 GHz to isolate interferences from wireless local area network (WLAN) and dedicated short-range communication (DSRC) applications. The transparency of this antenna of up to 80% is enabled by the fabrication on a conductive silver coated thin film (AgHT-8). Hence, the proposed transparent antenna is a suitable for UWB home entertainment network (IEEE 1394 over UWB network) for green building applications, where high data rates are required for multimedia transfer. Implementation of the proposed transparent antenna will reduce the space consumption due to its very low thickness and low profile, while at the same time increasing the aesthetic values of the installed wireless system due to its high transparency. |
| Author(s): | M. S. A. Rani, S. K. A. Rahim, P. J. Soh, B. M. Saad, M. I. Sabram, M. F. M. Yusoff |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 11 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1213 KB |
| Title: | Detection of the Faulty Sensors on Basis of the Pattern Using Symmetrical Structure of Linear Array Antenna |
| Abstract: | In this paper, a simple method is proposed to diagnose the position of the damaged sensors. The position of the damaged sensors is diagnosed on the basis of the null depth level and the number of nulls for the degraded radiation pattern. The method is initiated with tabulation of the array radiation pattern with a single damaged sensor. The corresponding pattern is set as the reference to the radiation pattern of the failed sensors. The tabulated damaged array sensors are compared to a configuration of the assumed damaged sensor. The radiation pattern with deeper null depth level will be the location of the damaged sensor. Moreover, the symmetrical sensor damaged (SSD) technique diagnose the position of damaged sensor, in which on the basis of nulls one can detect the location of damaged sensors. The proposed method diagnoses the location of damaged sensors on the basis of pattern without complex computation as compared to available methods. |
| Author(s): | S. U. Khan, M. K. A. Rahim, N. A. Murad, F. Zubir, O. Ayop, M. F. M. Yusoff, M. R. Hamid, R. Dewan |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 4 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1634 KB |
| Title: | Crucial Parameters and Optimization of High-Speed Bearingless Drives |
| Abstract: | Bearingless drives integrate the functionality of magnetic bearings and an electric machine into a single device. While this integration allows very compact drives offering all advantages of magnetic levitation, the design process becomes significantly more complex. This work deals with the numerous topological and geometric design decisions which need to be taken for such a bearingless drive. Additionally, the definition of suitable optimization targets for the electromagnetic simulation process is outlined. The proposed guidelines generate a complex relationship of different dependencies which is then fed into the MagOpt optimizer for the design of a high speed bearingless disk drive, which allows verifying the optimization results through measurement results from two prototype drives. |
| Author(s): | H. Mitterhofer, S. Silber |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 8 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1876 KB |
| Title: | Ultra-Wideband Six-port Network Constructed by 90° and In-Phase Power Dividers |
| Abstract: | This article proposes a six-port network design with an ultra-wideband operation from 3.1 to 10.6 GHz. The proposed six-port configuration is constructed by two types of power dividers with different phase characteristics of 0° (in-phase) and 90°. The new proposed configuration eliminates one unused port of the conventional six-port. Both components forming the proposed six-port are designed utilizing the microstrip-slot technique to accomplish the designated UWB operating frequency. The six-port is designed via the use of CST Microwave Studio (CST MWS) and realised by applying Rogers TMM4 substrate. Comparable simulated and measured performances are achieved in terms of S-parameters and phase differences between each consecutive port across UWB frequency range. |
| Author(s): | N. Seman, K. H. Yusof, M. H. Jamaluddin, T. A. Rahman |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 5 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1645 KB |
| Title: | Ultra Wideband Power Divider Design Implementing Microstrip with Slotted Ground |
| Abstract: | This article proposes a compact design of a two-section power divider, which operates over an ultra wideband frequency range of 3-11 GHz. The design approach of microtrip with slotline at the ground plane is applied to reduce the size of the circuit and to achieve wide bandwidth coverage. The rectangular slots are implemented at the ground plane, which is positioned symmetrically underneath the second and third arms of each microstrip quarter-wave transformer to reduce its length up to 33.34%. These attributes lead to an easily fabricated 20 mm x 23 mm compact power divider with a reduced size (by 23.33%). The bandwidth performance is improved up to 19.4% compared to a conventional divider. The design is realized by implementing the Rogers TMM4 substrate and simulated by using CST Microwave Studio. The power divider is verified by using a vector network analyzer (VNA). A good agreement between simulation and fabrication is achieved in terms of return loss, isolation and transmission coefficients across the UWB frequency range. |
| Author(s): | N. Seman, K. H. Yusof, M. H. Jamaluddin, T. A. Rahman |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 8 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1840 KB |
| Title: | Ground Penetrating Radar Radargram Filter using Singularity Expansion Method |
| File Type: | Conference Paper |
| Issue: | Volume: S12 Sparse Array Processing and Radar Sensing Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 261 KB |
| Title: | Investigation of Antennas for Car-to-Car Communications |
| File Type: | Conference Paper |
| Issue: | Volume: S17 Computational Electromagnetics, Advanced Algorithms and Emerging Applications/ High Performance Computing in Electromagnetics Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 414 KB |
| Title: | A High Gain Lens-Coupled On-Chip Antenna Module for Miniature-Sized Millimeter-Wave Wireless Transceivers |
| Abstract: | This paper presents high gain and compact Transmit/Receive (TX/RX) integrated antennas in a standard BiCMOS 130nm technology for millimeter-scale millimeter-wave (mm-wave) applications, including high data rate radios and high resolution radars. The proposed TX/RX antenna module utilizes an integrated dipole antenna for the receiver and a slot antenna for the transmitter, placed orthogonally. The achieved gain and radiation efficiency are 5.7dBi and 41.3% for the slot antenna, respectively, and 6dBi and 39% for the dipole antenna. The link budget is improved by 16dB by optimization on the geometry as well as application of a high resistivity hemispheric silicon dielectric lens. |
| Author(s): | M. Moosavifar, D. Wentzloff |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1640 KB |
| Title: | DOA Estimation in Heteroscedastic Noise with sparse Bayesian Learning |
| Abstract: | We consider direction of arrival (DOA) estimation from long-term observations in a noisy environment. In such an environment the noise source might evolve, causing the stationary models to fail. Therefore a heteroscedastic Gaussian noise model is introduced where the variance can vary across observations and sensors. The source amplitudes are assumed independent zero-mean complex Gaussian distributed with unknown variances (i.e., source powers), leading to stochastic maximum likelihood (ML) DOA estimation. The DOAs are estimated from multisnapshot array data using sparse Bayesian learning (SBL) where the noise is estimated across both sensors and snapshots. |
| Author(s): | P. Gerstoft, C. F. Mecklenbrauker, S. Nannuru, G. Leus |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1392 KB |
| Title: | A Symmetrical Fractal-based Balanced Branch-Line Coupler for Simultaneous Low- and Mid-band 5G Frequencies Applications |
| Abstract: | Symmetry is a key factor for Branch-Line Couplers (BLCs) in RF and microwave systems. This balanced approach evenly distributes power between two output ports, aiding impedance matching and reducing unwanted coupling and crosstalk, while increasing inputoutput isolation. Furthermore, the symmetrical design of BLCs ensures favorable return loss and phase balance, which are essential for phase-sensitive detectors and beamforming. This symmetry also guarantees consistent performance over a wide frequency range, making it suitable for broadband or multi-frequency applications. We present a compact BLC operating in two frequency bands, ideal for 5G sub-6 GHz applications. It uses Tshaped lines with folded lines and stubs in a Minkowski fractal shape, resulting in a size reduction of 90%. The design and simulation were performed using the CST Microwave Studio at 0.7 GHz and 3.5 GHz, achieving a new high frequency band ratio of 5. A prototype on Rogers RT5880 substrate (εr = 2.2,h = 0.787 mm) was tested to validate the design’s effectiveness, offering potential for modern wireless applications requiring versatile frequency band operation. |
| Author(s): | A. B. Shallah, F. Zubir , M. K. A. Rahim, Z. Yusoff |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 12 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 8981 KB |
| Title: | Using Circuit Simulation Optimization to Determine the Electrical Properties of Polymeric Composite Materials |
| File Type: | Conference Paper |
| Issue: | Volume: Computational Methods for Nondestructive Evaluation and Materials Characterization Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 168 KB |
| Title: | Unified Formulation for Evaluation and Visualization of Electric and Magnetic Fields Inside Waveguides and Cavities |
| Abstract: | The output of this research is an interactive software package developed to enhance and expedite the design of waveguides and cavity resonators through the computation and visualization of the electric and magnetic field distribution. The software features a userfriendly interface through which users can select one of seven different configurations and specify parameters of their design, such as structure dimensions, transverse electric or magnetic mode, mode numbers, operating frequency, number of points of any of the field components along the x, y, and z axis for rectangular structures, and any 2D plane angles between 0° to 360° for cylindrical structures. Both transverse and longitudinal field components can be visualized in vector, color contour or both. The software makes it easy for users to see how the changes of physical dimensions and operating frequency affect the field distribution. Moreover, the user interface allows users to select how visualizations of the field distribution are generated and displayed. Field distributions can be displayed as static images or video animations using appropriate sequencing of computed field values at different plane cuts. The software provides all necessary warning messages for invalid input parameters. Mathematical expressions of the field components used in this software were derived from the classical solution of the wave equations using the separation of variables technique in cartesian coordinates for rectangular configurations and cylindrical coordinates for all other configurations. Results obtained using this software were validated against values found in the literature for similar types of problems, and results show perfect agreement. |
| Author(s): | Z. Hasan, A. Elsherbeni |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 6 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 4961 KB |
| Title: | Uniaxial Dielectric Waveguide Filter Design Accounting for Losses Using Mode Matching Technique |
| Abstract: | Dielectric filters can provide compact solutions for filter design problems. However, most dielectrics exhibit uniaxial properties, as well as, losses that will undoubtedly affect performance if not accounted for. This paper derives dispersion relations for lossy uniaxial media in dielectric waveguides and also accounts for lossy conducting walls. The waveguide discontinuity problem in the presence of lossy uniaxial media and finite conductivity waveguide walls, is calculated by mode matching technique and the results are applied to a Ka band filter. The design specifications for the proposed filter are a 32.5 GHz center frequency with 6%. Good agreement between simulated and measured results are shown. |
| Author(s): | L. Murphy, J. Mautz, M. Yazdani, E. Arvas, S. Tozin |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 7 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 856 KB |
| Title: | Ultrawide band Negative Refraction Based on Moving Media Concept |
| Abstract: | The anomalous wave propagation in a homogeneous, isotropic and lossless medium that moves with a constant velocity along the axis of a rectangular waveguide; and its interesting properties lead us to the fact that the moving media may be regarded as double negative metamaterial (DNG). In this paper, the correct sign of the permittivity and permeability of an equivalent stationary media, for each TE and TM modes and for both low and high dielectric velocities are investigated and it is shown that this medium acts as a DNG material over specific frequency ranges. |
| Author(s): | A. Jafargholi, A. Jafargholi |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 11 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 665 KB |
| Title: | Ultra-wideband Flexible Implantable Antenna for Wireless Capsule Endoscopy System with Performance Improvement |
| Abstract: | The implantable antenna is an important part of the wireless capsule endoscopy (WCE) system to achieve wireless communication. This paper designed an ultra-wideband flexible implantable antenna for wireless capsule endoscopy system. With a very wide bandwidth, the antenna can completely cover the industrial, scientific, and medical frequency bands (ISM, 2.4-2.48 GHz) and Wireless Medical Telemetry Service (WMTS, 1.395-1.4 GHz). The expanded size of the proposed antenna is 18mm× 10mm× 0.1mm. The conformal technology of the antenna has further reduced the space of the system and achieved miniaturization. The capsule antenna in this paper is a compact planar monopole antenna fed by a coplanar waveguide, and it uses a flexible material as a dielectric substrate to achieve the conformal shape of the antenna. U-shaped ground branch (UGB) and a loaded split ring resonator (SRR) structure were used to further improve the antenna performance. Simulation and measurement results were basically the same. On the premise of radiation safety and miniaturization of the antenna, the ultra-wideband operation of the antenna was realized. This antenna design provided reference value for the design and application of the capsule antenna. |
| Author(s): | Y. Feng, P. Chen, S. Pan, G. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 6 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1325 KB |
| Title: | Ultra Wideband Microwave Ten-Port Reflectometer |
| Abstract: | This paper describes and simulates the Ultra Wideband (UWB) Ten-Port Reflectometer (TPR). It is based on the concept of well-known sixport structure so that numbers of measuring ports are increased to eight in order to improve reliability and accuracy as well. This article presents UWB (2 GHz to 12 GHz) reflectometer using Rectangular Waveguide (RWG). It is proved that increasing numbers of measuring ports leads to improving accuracy and reliability of structure so that each port with corresponding port help to make wideband reflectometer as well as having reliable and robust structure. This prototype of ten-port reflectometer is simulated by Agilent ADS and using RWG that has more bandwidth, less loss and high Q-factor than other common transmission lines, say microstrip, SIW and CPW. |
| Author(s): | A. Askarian, G. Moradi |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 1 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 468 KB |
| Title: | Tunneling of Spoof Surface Plasmon Polaritons through Effective Epsilon-Near-Zero Material |
| File Type: | Conference Paper |
| Issue: | Volume: 2-P2-F Metamaterials Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 516 KB |
| Title: | Tuning of Waveguide Bandstop Filter Properties by Changing the Physical Dimensions of Metamaterial Unit Cell |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling of Metamaterials and Transformation Based Devices Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 605 KB |
| Title: | Tunable Terahertz Plasmon-Induced Transparency in Resonator-Coupled Dirac Semimetal Waveguides |
| Abstract: | The bulk Dirac semimetal (BDS) is an interesting material, similar to graphene, which can dynamically adjust its optical properties via a variation in its Fermi energy or electrical voltage. In this work, a BDS-based plasmonic device, which enables tunable terahertz plasmon-induced transparency, was proposed and designed. By using the finite element method, the surface plasmon polariton and plasmon-induced transparency of this device were systematically investigated. The results demonstrate that the plasmoninduced transparency of such device can be dynamically tuned by varying its Fermi energy. When the Fermi energy changes from 55 meV to 95 meV, the maximum group delay time of the device increases from 13.2 ps to 21 ps. In the case of a cascading device, the maximum group delay time can be further pushed up to 44.57 ps. The influence of the ambient refractive index on the optical properties of the proposed device was also considered and investigated. |
| Author(s): | D. Wang, J. Yang, W. Wang, L. Yuan, X. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 6 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1609 KB |
| Title: | Tunable Bandstop Filter Based on Split Ring Resonators Loaded Coplanar Waveguide |
| Abstract: | In this paper, a novel electrical tunable bandstop filter based on coplanar waveguide (CPW) loaded with split ring resonators (SRRs) is proposed. The unit cell of the bandstop filter is formed by etching single SRR on the CPW back substrate side, and the SRRs can be excited by the CPW slot’s magnetic field. Lumped equivalent circuit models are developed to analyze the frequency responses, and it shows that by loading the common cathode varactor diodes at the split region of the SRR outer ring, the resonant frequency of the bandstop filter can be electronically adjusted by tuning the reverse voltage of the varactor diodes. The prototype with overall size of 26.6 mm ? 50 mm ? 0.508 mm was designed and fabricated to validate the proposed structure. The measured tunable resonant frequency of the fabricated bandstop filter is from 2.19 GHz to 2.31 GHz while a reverse bias voltage is varying from 0 V to 30 V. It also shows that the -10 dB bandwidth is less than 45 MHz. |
| Author(s): | Q. Xiang, Q. Feng, X. Huang |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 7 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 1138 KB |
| Title: | Triple-Band GCPW Rectifier for Harvesting EM Energy |
| File Type: | Conference Paper |
| Issue: | Volume: 3-3-D Wireless Power Transfer and Harvesting Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 383 KB |
| Title: | Transmission Bandgap of a Two-dimensional Coaxial Bragg Structure with Hybrid Filling Media |
| File Type: | Conference Paper |
| Issue: | Volume: 2-2-C Novel Electromagnetic Metamaterials and Their Applications Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 315 KB |
| Title: | TRANSMISSION AND REFLECTION CHARACTERISTICS OF A CLASS OF MODIFIED COPLANAR WAVEGUIDE STRUCTURES |
| Abstract: | In this paper, several geometries of a class of grounded coplanar waveguide (GCPW) are investigated using the finite difference time domain (FDTD) method, and their losses are computed. A uniform grounded coplanar waveguide (GCPW) structure is used as a reference case for the other non-uniform geometries. First, this reference case is studied. For this case, four geometries are proposed to study the transmission and loss effect of replacing parts of the dielectric substrate with free space. Afterwards, two new geometries are simulated to study the effect of introducing a neck and a gap in the microstrip feeding line, with and without a bridge that connects the two parts of the microstrip feeding line separated with the gap. The effect of adding a PEC cap above the microstrip feeding line, and connecting the two side ground planes, is also studied. The conductor attenuation is studied for the basic GCPW geometry. The power losses are also calculated for the uniform geometries. The line impedance is calculated for all geometries at several points. |
| Author(s): | Abdelnasser. A. Eldek, Atef. Z. Elsherbeni, Charles. E. Smith, Abdelnasser. A. Eldek, Atef. Z. Elsherbeni, Charles. E. Smith |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 2 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 378 KB |
| Title: | THz Square Cross Section Smooth Spline Horns as a Competitive Alternative to Corrugated Horns |
| File Type: | Conference Paper |
| Issue: | Volume: S09 Advances in Electromagnetic Modeling by WIPL-D - I Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 1111 KB |
| Title: | Three-Way Substrate Integrated Waveguide (SIW) Power Divider Design |
| File Type: | Conference Paper |
| Issue: | Volume: S48 Waveguides and Guided Structures II Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 307 KB |
| Title: | Three-bit Unit-cell with Low Profile for X-Band Linearly Polarized Transmitarrays |
| Abstract: | In this paper, we present a three-bit phase resolution and low profile unit-cell structure for X-band passive transmitarrays. The unit-cell is implemented using four metallic layers printed on two substrates separated by an air gap. The phase shift is achieved by a combination between current flow modification on middle layers and the variation of the size of path elements. Eight unit-cells are optimized to provide eight phase states with a step of 45°. Experimental results are conducted by using WR-90 waveguide to validate the design. These eight unit-cells cover a wide -3 dB transmission bandwidth of 15% and exhibit a low thickness of 0.18λ0. |
| Author(s): | B. D. Nguyen, M. T. Nguyen |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 9 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1891 KB |
| Title: | Theoretical and Experimental Analysis of Rectangular Waveguides with Isotropic Chiral Media |
| File Type: | Conference Paper |
| Issue: | Volume: Poster Sessions 2 Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 238 KB |
| Title: | The Use of Offset Coupled Microstrip Combline Filters for IF Filters Requiring High Selectivity |
| File Type: | Conference Paper |
| Issue: | Volume: EM Simulations Using Sonnet - II Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 820 KB |
| Title: | The Time-Bandwidth Limit in Optical Nanostructures and Its Relation to Nonreciprocity |
| File Type: | Conference Paper |
| Issue: | Volume: S08 Design, Analysis and Applications of EM Metasurfaces I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 105 KB |
| Title: | The Temperature Compensation for TE011 Mode Resonator with Bimetal Material |
| Abstract: | This paper proposes a temperature compensation design for TE011 mode resonator based on multiphysics analysis. The relationship between structure and electrical performance of circular waveguide resonator is specifically analyzed. Furthermore, a novel temperature compensation structure with bimetal material is proposed by using multiphysics analysis. The proposed TE011 mode resonator is fabricated and tested to verify the design method. The temperature drift coefficient of the compensated TE011 mode resonator can be dramatically reduced from 21.387 ppm/°C to 0.93ppm/°C. |
| Author(s): | Q. Wu, J. Zhang, Y. Yang, X. Shi |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 7 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1505 KB |
| Title: | The Substrate Integrated Waveguide T-junction Power Divider with Arbitrary Power Dividing Ratio |
| Abstract: | An X-band H-plane wideband substrate- integrated waveguide (SIW) T-junction power divider with unequal-power-division ratio is presented. Several inductive posts are used to have arbitrary power dividing ratio and also to control the phase difference. The position and diameter of these posts tune the power-split ratio and the phase difference in whole bandwidth. Parametric studies have been done to choose the best positions and diameters to get better results. Two different prototypes have been verified the proposed technique. They are designed and fabricated at a center frequency of 11 GHz. The measured input impedance bandwidths are 54% for ?out =3 dB and 45% for ?out =6 dB respectively. |
| Author(s): | A. Piroutiniya, P. Mohammadi |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 4 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1267 KB |
| Title: | The Multiresolution Frequency Domain Method for the Efficient Analysis of Ferrite Loaded Waveguides |
| File Type: | Conference Paper |
| Issue: | Volume: Finite Difference Methods: Recent Developments and Applications Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 457 KB |
| Title: | The Design of Planar Slot Arrays Revisited |
| Abstract: | Design procedures for planar waveguide slot arrays have been known and used for years, but the inexperienced designer is often faced with a number of practical problems when trying to implement them, especially in the case of larger arrays consisting of sub-arrays. Some helpful hints concerning the numerical implementation are provided. These include an effective procedure to avoid the necessity of good initial guesses for the unknown dimensions and recommendations for the subdivision of the nonlinear equations into smaller groups. Other practical aspects which are not explicitly defined elsewhere in the literature, are also addressed. |
| Author(s): | J.C. Coetzee, J. Joubert, J.C. Coetzee, J. Joubert |
| File Type: | Journal Paper |
| Issue: | Volume: 15 Number: 1 Year: 2000 |
| Download Link: | Click here to download PDF File Size: 3222 KB |
| Title: | The Design of a High Gain Dual-Polarized Quad-Ridged Circular Horn Antenna for Wideband EMC Test Applications |
| Abstract: | This paper presents the design of a high gain broadband quadruple-ridged circular horn antenna for Electromagnetic Compatibility (EMC) testing. The proposed antenna contains a wideband feed structure as a transition between coaxial line and quad-ridged circular waveguide behind the conical horn antenna. The wideband matching between impedances at the apertures of the feed and the horn is achieved with a tapering at the flare section along the horn length, which is obtained after a detailed investigation of various tapering profiles. The antenna is designed to operate in horizontal and vertical polarizations (dual linear polarization) simultaneously in EMC tests. This implementation is found to present a return loss greater than 10 dB, isolation level higher than 28 dB, high-gain (minimum 13.6 dBi) and low-gain variation of 4.5 dBi within the frequency range of 1-6.75 GHz (6.75:1 bandwidth) at both polarizations, which is a desired feature in radiated emission and immunity tests. |
| Author(s): | B. Solak, M. Secmen, A. Tekin |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 9 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2407 KB |
| Title: | The Design of 276 GHz Triple-Push VCO Based on 65nm CMOS Process Using Slow-Wave Effect |
| File Type: | Conference Paper |
| Issue: | Volume: 4-P4-C THz Antenna, Circuit and System Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 269 KB |
| Title: | Suppression of Anisotropic Birefringence in a Rectangular Waveguide |
| File Type: | Conference Paper |
| Issue: | Volume: S45 Electromagnetic Methods for Devices and Applications I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 136 KB |
| Title: | Superformula-Based Compact UWB CPW-Fed-Patch Antenna With and Without Dual Frequency Notches |
| Abstract: | This paper presents two new designs of UWB coplanar waveguide (CPW)-fed-patch antennas operating in the FCC frequency band (3.1-10.6 GHz). The first design uses the superformula to produce a circular patch with sawtooth-like circumference. As compared to a regular circular patch antenna whose diameter is 25 mm, the proposed circular patch has a smaller diameter of 18.2 mm. Moreover, the proposed antenna covers the entire FCC band unlike a regular circular patch of the same radius. The second design introduces two frequency notches at 3.3-3.8 GHz (WiMAX) and 5-5.9 GHz (WLAN) using two arc shaped circular slots etched on the circular patch and a split-ring resonator (SRR) that is placed on the opposite side of the substrate. Measurements and simulations using HFSS show that the return loss is better than 10 dB across the band except at the two notch locations in Design II. Results are also presented for the radiation pattern and peak gain of both designs. Each of the proposed antennas has a compact size of 24 mm x 19 mm on a 1.5 mm Rogers Substrate (epsilon r=3.85). |
| Author(s): | A. A. Omar, S. Naser, M. I. Hussein, N. I. Dib, M. W. Rashad |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 11 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1949 KB |
| Title: | Substrate Integrated Waveguide-Fed Tapered Slot Antenna With Smooth Performance Characteristics Over an Ultra-Wide Bandwidth |
| Abstract: | We present an ultra-wide extended Kband (18 GHz – 30 GHz) planar linear tapered slot antenna (LTSA) design. From a parametric study involving eight designs, the best compromise LTSA is selected in terms of flattest gain and beam width and most symmetric beam width. The design is antipodal with alumina (?r = 10) substrate and fed with substrate integrated waveguide (SIW). Regular corrugations improve cross-polarization, input return loss, and gain. Numerical simulations use finite element analysis and time domain finite integration technique field solvers. The resulting design has half power beam widths (HPBW) of only ± 3.2° and ± 2.5° variation in frequency in the E- and H-planes, respectively. Cross-polarization levels at boresight are 35.7 dB at 18 GHz and 17.4 dB at 30 GHz, return loss is better than -11.7 dB and gain is 9.23 dB with ± 0.40 dB variation with frequency. Alternatively, for imaging systems requiring efficient illumination of a reflector or focusing elements, a second resulting design shows near-perfect beam symmetry with HPBWE/HPBWH = 0.91. These two LTSAs are good candidates for dual-polarization focal plane array feed applications in astronomy imaging. |
| Author(s): | L. S. Locke, J. Bornemann, S. Claude |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 988 KB |
| Title: | Substrate Integrated Waveguide Microwave Filter Tuning Through Variable-Fidelity Feature Space Optimization |
| File Type: | Conference Paper |
| Issue: | Volume: EM-Simulation-Driven Design: Modeling and Optimization Number: Year: 2014 |
| Download Link: | Login To Download (For Members) File Size: 473 KB |
| Title: | Substrate Integrated Waveguide Antenna at Millimeter Wave for 5G Application |
| Abstract: | This paper presents a dual-band slot antenna using substrate integrated waveguide (SIW) technology at 26 and 28 GHz. High loss is one of the main challenges faced by 5G base station network due to the severe path loss at high frequency. Hence, high gain antennas are required for 5G base station applications to overcome path loss issue. Hence, this work designs a high gain SIW antenna based on slot technology to excite dual-bands with high gain capability. The antenna is designed with two slots shaped to resonate at two different frequencies: 26 and 28 GHz. The antenna is analyzed using CST software and fabricated on Roger RT5880 substrate with permittivity of 2.2 and lost tangent of 0.0009 with thickness of 0.508 mm. The design operates at 26 and 28 GHz with measured reflection coefficients less than -10 dB. Measured high gains of 8 and 8.02 dB are obtained at 26 and 28 GHz, respectively. Overall, the antenna showed good performance that would benefit the fifth-generation applications. |
| Author(s): | Y. M. Hussein, M. K. A. Rahim, N. A. Murad, H. O. Hanoosh, N. B. M. Nadzir |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 4 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 2076 KB |
| Title: | Study, Design and Fabrication of a CPW Fed Compact Monopole Antenna with Circular Polarization for Ultra Wide Band Systems Application |
| Abstract: | A compact circularly polarized square slot antenna (CPSSA) is presented in this paper, which is appropriate for UWB applications requiring high data rate transmission. This antenna operates across 2.8 GHz to 10.8 GHz with an impedance bandwidth (IBW) of 117.6% for VSWR less than or equal to 2. The antenna consists of a trapezoidal shaped radiation patch which is fed through a coplanar waveguide (CPW) and includes two inverted L-shaped ground arms at the two opposite corners of the slot to excite two orthogonal resonant modes for circular-polarization (CP) radiation. Furthermore, two square slits at the two other opposite corners of the slot are applied to enhance its IBW. The antenna exhibits CP bandwidth of 50.5% across 3.7 GHz-6.2 GHz, which is suitable for WLAN, WiMAX and C-bands. In addition, the antenna has a considerably compact volume of 25×25×0.8 mm3. The measured and simulated results confirm the usefulness of the antenna for practical applications. |
| Author(s): | M. Shokri, S. Asiaban, A. Amiri |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 9 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1746 KB |
| Title: | Structural Optimization of an Optical 90 Degree Hybrid Based on a Weaklyguided 4x4 Multimode Interference Coupler Using a Parallelized Real-coded Micro-genetic Algorithm |
| Abstract: | The optimal design of a 4x4 multimode interference (MMI) coupler as an optical 90° hybrid based on a weakly-guided optical waveguide was considered. Seven geometrical parameters of a 4x4 MMI coupler were optimized by a real-coded micro-genetic algorithm, and parallelized using a message-passing interface. The beam-propagation method was used to evaluate the fitness of the MMI coupler in the optimization process. The optimized 4x4 MMI coupler showed a common-mode rejection ratio greater than 28.9 dBe and a phase error less than 2.52° across a wavelength range of 1520 to 1580 nm, which satisfied typical system requirements. The optimization process was executed on a Beowulf-style cluster comprising five identical PCs, and its parallel efficiency was 0.78. |
| Author(s): | T. Yasui, J. Sugisaka, K. Hirayama |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 5 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1566 KB |
| Title: | Spurious Solutions in Fast Frequency Sweeps |
| File Type: | Conference Paper |
| Issue: | Volume: In Tribute To Dr. Zoltan Cendes Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 68 KB |
| Title: | Spoof Surface Plasmons on the Dielectric-loaded Doubly-corrugated Grating for Terahertz Applications |
| File Type: | Conference Paper |
| Issue: | Volume: 1-SP-2 Electromagnetic Characteristics of Complex Media Simulated by Time Domain Method I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 359 KB |
| Title: | Space-Mapping-Enhanced Kriging Surrogates for Accurate Modeling of Microwave Structures |
| File Type: | Conference Paper |
| Issue: | Volume: Optimization Methods for EM Applications Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 1037 KB |
| Title: | Space-Frequency Domain Iterative Method for Modes Analysis of Planar Waveguides |
| Abstract: | We describe a space-frequency domain iterative algorithm to analyze the modes of planar optical waveguides. The one dimensional Maxwell equation was transformed into space-frequency domain by Fourier transform, and became an integral equation which could be solved by an iterative method. For any refractive index profiles, the effective index and mode field distribution are given simultaneously. The numerical result shows that this method is accurate and flexible for planar optical waveguides with any structure. |
| Author(s): | L. Bingxin, Z. Baorong |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 8 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 353 KB |
| Title: | Space Use Radial Line Slot Antenna with Honeycomb Structure |
| File Type: | Conference Paper |
| Issue: | Volume: Student Paper Competition Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 325 KB |
| Title: | SOME EXPERIENCES IN USING NEC2 TO SIMULATE RADIATION FROM SLOTS ON CYLINDERS |
| Abstract: | A numerical method based on use of the NEC2 code has been used to study radiation from a slot in the surface of a conducting cylinder and the results used in a comparison with the eigenfunction series solu-tion. The two cases of an axial and circumferential slot have been taken as representative between them of the more general case of an inclined slot. In the case of a circumferential slot, truncation of the cylin-der to finite length has been found in all cases to lead to numerical and analytic results which are in poor agreement and this has been accounted for with an argument based on the geometrical theory of dif-fraction. However this alone is not enough to explain what is observed with axial slots where, for small cyl-inders, agreement of the two approaches is good but fails for larger cylinders. It is postulated that this is due to excitation of waveguide modes on the inside of the larger cylinders and the result confirmed by clos-ing the ends of the cylinder in the NEC2 model with a system of radial wires, when agreement is again re-stored. |
| Author(s): | S. H. H. Lim, H. E. Green, C. E. Brander, S. H. H. Lim, H. E. Green, C. E. Brander |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 1 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 422 KB |
| Title: | Slotted Waveguide Transitions for Spatial Power Combining |
| File Type: | Conference Paper |
| Issue: | Volume: Posters Session 2 Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 136 KB |
| Title: | Slotted Coaxial Line and Associated Measurement System for Determination of Dielectric Properties of Gas Plasma |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Electromagnetic Modeling by WIPL-D Software Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 1185 KB |
| Title: | Size-Reduced Bandpass Filter Using HMSIW and Modified U-Shaped DGS Slot-Pairs |
| File Type: | Conference Paper |
| Issue: | Volume: S18 Electromagnetic Metamaterials and Metasurfaces Number: Year: 2015 |
| Download Link: | Login To Download (For Members) File Size: 203 KB |
| Title: | SIW Rotman Lens with Planar Slot Array Antenna at Ku-band |
| Abstract: | A multi-beam antenna, which is the combination of a Rotman lens and a planar slot array antenna, is designed in this paper. The lens and the slot array are designed for 15.5 to 16.5 GHz frequency range and implemented in the same substrate using SIW structure. The Rotman lens with 7 input ports and 7 output ports are connected to a planar slotted array antenna with 7 waveguides. This multi-beam antenna consists of seven beams at angles of 0°, ±10°, ±20° and ±30° symmetrically. This antenna is designed for terrestrial and satellite applications, where the low cost, low profile and light multi-beam antennas are needed. Simulated and measured results show that the amplitude and phase distributions and scattering parameters of the antenna are in good agreement. In addition, the SLL, HPBW, main beam direction and cross polarization levels of all the radiation patterns are desirable. |
| Author(s): | S. A. Hosseini, Z. H. Firouzeh, M. Maddahali |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 6 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 2116 KB |
| Title: | SIW like Bull-Eye Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: S04 Printed, Flexible and Reconfigurable Antenna Implementations Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 464 KB |
| Title: | SIW Circularly-Polarized Filtering Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: 1-P1-A Student Paper Contest Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 611 KB |
| Title: | Single-mode Condition and Bending Loss Analysis of Ultrafast Laser-inscribed Mid-infraredWaveguides in GeAsSe Chalcogenide Glass |
| Abstract: | In this study, single-mode conditions and bending losses of optical waveguides based on Ge33As12Se55 chalcogenide glass, commercially known as IG2, for astrophotonic devices in the mid-infrared spectral range are numerically analyzed. The scalar finite-element method was used to analyze singlemode conditions. For the bending-loss analysis, equivalent straight waveguides of bent waveguides were analyzed using the two-dimensional finite-difference beam-propagation method. The results revealed design rules for astrophotonic optical integrated circuits in the mid-infrared spectral range. |
| Author(s): | T. Yasui |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 12 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 1855 KB |
| Title: | Single-, Dual- and Wide-Band Frequency-Reconfigurable Antenna with Annular Ring Slots |
| Abstract: | This paper presents a frequency reconfigurable antenna enabled using a pair of annular ring slots on a coplanar waveguide (CPW) ground plane. Its initial wideband operation mode from 3 GHz to 6 GHz can be reconfigured into six additional modes: a dual–band mode and five single-band modes, with minimum reflection coefficients (S11) of -10 dB. For demonstration and proof-of-concept purposes, metal switches have been used to represent the switches in simulations and measurements. The ON state is emulated using shorted metal switches, whereas the OFF state is emulated using an open. Good agreements are indicated for simulated and measured S11 and radiation patterns. |
| Author(s): | M. C. Lim, S. K. A. Rahim, M. R. Hamid, P. J. Soh, M. I. Sabran, A. A. Eteng, M. R. Ramli |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 11 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 2128 KB |
| Title: | Single Mode Field Derivation and Simulation of a Dual Ridged Waveguide Dual Probe |
| File Type: | Conference Paper |
| Issue: | Volume: S21 EM-Simulation-Driven Design: Modeling and Optmization Number: Year: 2015 |
| Download Link: | Login To Download (For Members) File Size: 141 KB |
| Title: | Simulation-Driven Design of Microstrip-to-CPW Transitions Using Variable-Fidelity EM Models |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic-Simulation-Driven-Design: Modeling and Optimization Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 376 KB |
| Title: | Simulation Analysis of Cross Polarization Property of Waveguide Slot |
| File Type: | Conference Paper |
| Issue: | Volume: 5-P-1 Poster Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 291 KB |
| Title: | Signal Propagation Modeling Based on Weighting Coefficients Method in Underground Tunnels |
| Abstract: | The propagation of electromagnetic waves guided in tunnels and mines is an area of scientific study which is hard to model due to multiple reflections on walls and surrounding obstacles. A novel propagation model for underground tunnels based on the weighting sum of the log-distance propagation model, the modified waveguide model and, the far zone propagation model for the ultra-high frequency (UHF) band is proposed in this paper. The propagation model is divided into five regions based on the distance between the transmitter and the receiver. Each region shows a different propagation characteristic and modeled with weighting sum of the base propagation models. Our model was tested in a tunnel with 2 m x 1.5 m cross-section and 250 m length. Measurement results are consistent with the proposed propagation model. |
| Author(s): | Y. Karaca, O. Tamer |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2308 KB |
| Title: | Shift-Inverse Technique in TLM-ROM |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Advances in Time Domain Modeling Techniques Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 217 KB |
| Title: | Shielding Effectiveness of Three Dimensional Gratings using the Periodic FDTD Technique and CPML Absorbing Boundary Condition |
| File Type: | Conference Paper |
| Issue: | Volume: Special Session: Electromagnetic Modeling by WIPL-D Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 203 KB |
| Title: | Sensitivity Analysis of the Orthorhombic Design Parameters in the Artificially Biaxially Dielectric Crystal |
| Abstract: | A full-wave modeling and simulation analysis method is presented for performing sensitivity analysis of artificial uniaxial and biaxial crystals previously reported for study with waveguide measurement systems. Small occlusions were machined into bulk dielectric material to impose effectively biaxial material properties. Here, the primary design parameters for orthorhombic occlusions are presented. Using multivariate parameter estimation, the effective material properties are characterized in a way that is equivalent to waveguide measurement methods. The advantage in using full-wave simulation allows investigation beyond measurement and fabrication capabilities, but is still limited because of the mesh size needed to model the fine geometric sizes of the occlusions in the crystal. The analysis shows that the effects of the primary design parameters on anisotropy can achieve 2-3 dB of axial difference for the biaxially diectric crystal. Although, only the dielectric case is presented, the multivariate estimation method used to estimate the material parameters is applicable for characterizing lossy and magnetic materials. |
| Author(s): | J. Brand, M. A. Saville |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 10 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 335 KB |
| Title: | Scattering by Closed and Unclosed Metallic Rings in a Circular Waveguide |
| File Type: | Conference Paper |
| Issue: | Volume: Poster Session Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 383 KB |
| Title: | Scan Blindness Elimination Using Composite Defected Ground Structures and Edge-coupled Split Ring Resonators |
| Abstract: | A novel compact composite structure, composed of double-U shaped defected ground structure (DGS) and edge-coupled split ring resonator (E-SRR), is presented in this paper. The composite structure is integrated into microstrip array to reduce the interelement mutual coupling, with the aim to eliminate the scan blindness and improve the scanning performance. The three kinds of two-element arrays (without composite structure, with only DGS and with composite structure) are thoroughly simulated, measured, and compared. The results show that, the reduction in mutual coupling of 11 dB between elements in E-plane is obtained with the use of composite structure. It is worth mentioning that, approximately 2dB gain improvement and 2.4dB side lobe suppression are both attained, in comparison with the array with only DGSs. Finally, the scan properties of three kinds of infinite microstrip phased arrays are studied by the waveguide simulator method. The results indicate that the scan blindness in an infinite microstrip phased array can be well eliminated by virtue of the effect of the proposed composite structures, in accordance with results obtained by active patterns of the centre element in 9×5 array. |
| Author(s): | M. C. Tang, S. Xiao, C. J. Li, C. Wei, B. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 7 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 1531 KB |
| Title: | Rule for Mode Coupling Efficiency in Optical Waveguide Crossing |
| Abstract: | Crossing an optical waveguide requires a beam coupling from free space to waveguide at the entrance plane and another beam coupling from waveguide to free space at the exit plane of the waveguide. The aim of this paper is to provide a simple rule expressing the relationship between the involved numbers of free and guided modes that efficiently rebuild the field at each end of the waveguide. Using a numerical program built on Maple software, the rule was determined to be effective independently of the ratio between the beam spot size and the waveguide radius. |
| Author(s): | B. Bentouhami, Z. D. Kaddour |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 5 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 2436 KB |
| Title: | Role of Surface Geometric Patterns and Parameters in the Dispersion Relations of Spoof Surface Plasmon Polaritons at Microwave Frequency |
| Abstract: | Spoof surface plasmon polaritons (SSPPs) can be excited using geometric shapes on conducting surfaces in microwave (MW) regime. They are eminent as compared to the conventional microstrip (MS) transmission lines, due to their better efficiency and compactness in high density and high-speed circuitry. In this work, we compare normalized dispersion curves (DCs) of different groove shapes engineered on the planar metallic strip with the variation of geometric parameters of the structure, which are obtained by Eigen-mode solver of ANSYS’s HFSS. It is found the dispersion characteristics are determined by the shape and the asymptotic frequency can finely be tuned through the geometric parameters. All DCs deviate further from the light line indicating slow propagation of SSPPS. The performance of rectangular grooves is clearly outstanding; however, the circular grooves behave comparably better than Vee-groove. Further, a low pass plasmonic filter has been proposed with semicircular gradient subwavelength grooves designed on a planar metallic strip with transition sections to match both the impedance and momentum of MS line and the plasmonic waveguide. Results of S-parameters and magnitude of electric field distributions show excellent transmission efficiency from fast guided wave to slow SSPPs. It is also observed that the confinement of such surface waves is dependent on the geometric parameters which can be useful in plasmonic structure engineering and fine-tuning the cutoff frequencies, hence posing a new prospect for advanced plasmonic integrated devices and circuits. |
| Author(s): | R. S. Anwar, L. Mao, H. Ning |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2035 KB |
| Title: | Robust and Efficient Model-Order Reduction for Lossless Microwave Structures Using the Impedance Formulation of the Finite Element Method |
| File Type: | Conference Paper |
| Issue: | Volume: S18 Computational Electromagnetics Advanced Algorithms and Emerging Applications I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 248 KB |
| Title: | RF Magnetic Field Profiling with a Dielectric Bore Lining for Traveling Waves in a 3-T MRI Scanner: A Computational Study |
| Abstract: | Traveling-wave magnetic resonance imaging (MRI) can be advantageous over the classical, quasistatic or near-field MRI. However, it is restricted to ultra-high static magnetic fields in the scanner and the correspondingly high RF excitation magnetic field frequencies due to fundamental constraints in cutoff frequencies of the MRI bore, considered as a waveguide. Through a computational study, we propose translating traveling-wave ideas to a 3-tesla scanner, where the RF magnetic field frequency is 127.8 MHz, using a highpermittivity dielectric layer (lining) that is built into the bore. With the lining, we can achieve traveling-wave modes inside the imaging phantoms even at 3 T, where this is generally not possible. We present results obtained using the higher order method of moments in the surface integral equation formulation, previously established as an efficient, accurate, and reliable technique for modeling of RF fields in MRI applications. Our simulations of a simple circularly polarized RF probe and dielectric lining give rise to a considerably uniform circularly polarized RF magnetic field inside phantoms in the clinical scanner. |
| Author(s): | M. M. Ilic, A. A. Tonyushkin, P. S. Athalye, N. J. Sekeljic, A. J.M. Kiruluta, B. M. Notaros |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 3 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1521 KB |
| Title: | Response Sensitivity Analysis with Frequency-Domain Full-Wave Electromagnetic Solvers |
| File Type: | Conference Paper |
| Issue: | Volume: Optimization and Solution of Complex EM problems Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 258 KB |
| Title: | Research of Medical and Industrial Applications of Microwaves Supported by SEMCAD |
| File Type: | Conference Paper |
| Issue: | Volume: SEMCAD X: Recent Modeling Advances for Virtual Prototyping Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 426 KB |
| Title: | Reflection compensation scheme for the efficient and accurate computation of waveguide discontinuities in photonic crystals |
| Abstract: | Abstract—We presented a novel method for the accurate and efficient computation of the reflection and transmission coefficients of waveguide discontinuities within planar photonic crystals (PhCs). This method proposes a novel kind of field source that optimally excites the dominant waveguide mode and mimics procedures that are typically used for the measurement of reflection coefficients. This technique may be applied to arbitrary field simulators working in the frequency domain. The presented reflection compensation scheme is elucidated along the Method of Auxiliary Sources (MAS). In order to verify the results, we compare two test cases with the rigorous connection technique provided by the Multiple Multipole Method (MMP). |
| Author(s): | D. Karkashadze, R. Zaridze , A. Bijamov, D. Karkashadze, R. Zaridze , A. Bijamov |
| File Type: | Journal Paper |
| Issue: | Volume: 19 Number: 1 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 1069 KB |
| Title: | Reducing Power Coupling Loss between Laser Diodes and Planar Optical Waveguides by Using Tapers |
| File Type: | Conference Paper |
| Issue: | Volume: Guided Waves in Non-Standard Media Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 96 KB |
| Title: | Reconfigurable 2×1 CPW-Fed Rectangular Slot Antenna Array (RSAA) Based on Graphene for Wireless Communications |
| Abstract: | This article presents a 2×1 CPW ultra wideband rectangular slot antenna array (UWB-RSAA) with a modified circular slot shape to support a high data rate for wireless communications applications. The proposed antenna array dimensions are 0.7λo×0.8λo×0.064λo at the resonant frequency 1.8 GHz. It is fabricated on Rogers RO4003 substrate and fed by using a coplanar waveguide (CPW). A graphene layer is added on one side of the substrate to realize frequency reconfigurability and improve the array gain. The proposed array acquires -10 dB impedance bandwidth of the RSAA that extends from 1.7 GHz to 2.6 GHz, from 3.2 to 3.8 GHz, and from 5.2 GHz to 7 GHz. The proposed array achieved a realized peak gain of 7.5 dBi at 6.5 GHz at 0 Volt bias with an average gain of 4.5 dBi over the operating band. When the graphene bias is increased to 20 Volt, the antenna bandwidth extends from 1 GHz to 4 GHz and from 5 to 7 GHz with a peak gain of 14 dBi at 3.5 GHz and an average gain of 7.5 dBi. The linearly polarized operation of the proposed array over the operating bands makes it suitable for short-range wireless communications . |
| Author(s): | D. M. Elsheakh, O. M. Dardeer |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 6 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1678 KB |
| Title: | Recent extensions in FEKO: Parallel MLFMM and waveguide excitations |
| File Type: | Conference Paper |
| Issue: | Volume: FEKO Modeling and Analysis - 1 Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 202 KB |
| Title: | Recent Advances in FDTD Modeling of Electromagnetic Wave Propagation in the Ionosphere |
| Abstract: | Finite-Difference Time-Domain (FDTD) modeling of electromagnetic wave propagation in the Earth-ionosphere waveguide has gained significant interest over the past two decades. Initially, FDTD modeling capabilities were largely limited to two-dimensional models assuming a plasma ionosphere (but incapable of accounting for Faraday rotation), or to threedimensional global models assuming a simple, isotropic conductivity profile ionosphere. Two algorithm developments have recently advanced the state-of-the-art in electromagnetic wave calculation capabilities in the ionosphere: (1) A new, three-dimensional efficient FDTD magnetized plasma model. (2) A Stochastic FDTD (S-FDTD) model of magnetized ionospheric plasma. The first capability permits longer-distance, higher frequency and higher altitude propagation studies by greatly reducing the memory requirements and simulation time relative to previous plasma models. The second capability introduces for the first time a way of solving for not only mean electromagnetic field values, but also their variance. This paper provides an overview of these two recent advances. |
| Author(s): | B. T. Nguyen, A. Samimi, J. J. Simpson |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 12 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 516 KB |
| Title: | Recent Advances for the Full-Wave Analysis and Design of Waveguide Filters for Space Applications |
| File Type: | Conference Paper |
| Issue: | Volume: Efficient Microwave Subsystem Design and Optimization Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 253 KB |
| Title: | Recent Advance in Neuro-Transfer Function-Assisted Yield-Driven EM Optimization |
| File Type: | Conference Paper |
| Issue: | Volume: S40 Advanced Optimization of Electromagnetic Structures - III Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 618 KB |
| Title: | Realization of a Sub-harmonic Mixer with a Substrate Integrated Waveguide Filter |
| File Type: | Conference Paper |
| Issue: | Volume: Design and Analysis of Advanced Circuit Architectures Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 373 KB |
| Title: | Ray Tracing Using Shooting-Bouncing Technique to Model Mine Tunnels: Theory and Verification for a PEC Waveguide |
| Abstract: | We present a shooting-bouncing approach to ray-tracing as applied to signal propagation modeling in electrically large waveguides, such as underground mine tunnels at wireless communication frequencies. The method is verified for a dominantmode rectangular metallic waveguide excited by a dipole antenna. |
| Author(s): | B. A. Troksa, C. L. Key, F. B. Kunkel, S. V. Savic, M. M. Ilic, B. M. Notaros |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 2 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1310 KB |
| Title: | Ray Tracing Using Shooting-Bouncing Technique to Model Mine Tunnels: Theory and Verification for a PEC Waveguide |
| File Type: | Conference Paper |
| Issue: | Volume: S14 Numerical Methods for Analysis, Design and Measurement of Antennas I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 652 KB |
| Title: | Protection of Computer Enclosure against Coupled Electromagnetic Interference |
| Abstract: | In this paper some suggested protection methods is proposed to improve the shielding effectiveness of computer enclosures. Slots and holes on the computer enclosure are divided into five types, and the coupled electromagnetic interference (EMI) into the enclosure is computed using the finite-difference time-domain (FDTD) method when each type slot exists. From comparison of both time domain electric field waveform and field distribution in the enclosure, vent array, joint laps, CD-ROM and display are found to be the main ways that the EMI penetrated into the enclosure. To improve the protection of the enclosure, waveguide window is used to replace vent array. Additionally, rivet number is increased, depth of the joint laps is increased and conductive gaskets are filled into the joint laps. From numerical analyses, it can be demonstrated that the suggested methods are efficient to improve shielding effectiveness of the computer enclosure. Some suggested methods are also proposed for the CD-ROM and display protection. |
| Author(s): | R. Xiong, W. Yang, H.-L. Chen, Y.-T. Duan |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 11 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2782 KB |
| Title: | PROPAGATION OF VLF RADIATION IN THE EARTH-IONOSPHERE WAVEGUIDE EXCITED BY AN AIRBORNE DUAL TRAILING WIRE ANTENNA |
| Abstract: | Field strength variations produced by an orbiting aircraft dual trailing wire VLF transmitting antenna are investigated. The towplane is assumed to be executing a circular orbit at a constant altitude and speed. A steady-state mechanical model is adopted for determination of the shape of the dual trailing wire antenna. The exact current distribution on this antenna is calculated using the Numerical Electromagnetics Code (NEC) which is based on a method of moments solution of the Electric Field Integral Equation (EFIE). A propagation code developed at the Naval Ocean Systems Center (NOSC) called TWIRE has been modified to be used in conjunction with NEC. This modified version of TWIRE has been called TWIRENEC. The TWIRENEC code uses the current distribution information provided by NEC to determine the dipole moments for a segmented antenna. The wire segmentation geometry and corresponding dipole moments are then used to calculate the electric field strength as a function of distance and azimuth in the earth-ionosphere waveguide. The waveguide can be considered as either horizontally homogeneous or inhomogeneous. It is demonstrated that the periodic variations in field intensity resulting from an orbiting transmitter are a function of receiver position. These periodic variations can range from a small fraction of a dB to several dB depending upon the location of the receiver with respect to the transmitter. A point dipole approximation of the dual trailing wire antenna is suggested for use in the study of VLF radiation excited by an orbiting antenna in the presence of wind shear. The point dipole approximation is applied to estimate the field strength variations caused by a yo-yo oscillation of the transmitting antenna as it orbits. These yo-yo oscillations are characterized in terms of the change in verticality of the point dipole which occurs over one complete orbit. [Vol. 8, No. 2 (1993), pp 72-92] |
| Author(s): | D.H. Werner, J.K. Breakall, R. J. Lunnen, D.H. Werner, J.K. Breakall, R. J. Lunnen |
| File Type: | Journal Paper |
| Issue: | Volume: 8 Number: 2 Year: 1993 |
| Download Link: | Click here to download PDF File Size: 899 KB |
| Title: | Propagation Mode in a V-shaped Silicon Groove Waveguide Embedded with Metal Nanowires |
| File Type: | Conference Paper |
| Issue: | Volume: 9-P-2 Poster Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 275 KB |
| Title: | Powering Sensors in IoT System by Using Compact Seven Band PIFA Rectenna |
| Abstract: | A compact seven band coplanar waveguide fed planar inverted F antenna (PIFA) is presented. The proposed antenna is designed to harvest the ambient radio frequency energy at GSM 900, GSM 1800, LTE band 11 and 7, UMTS 2100, Wi-Fi 2.4, LTE and WIMAX 5.2. The antenna is simulated using 3D electromagnetic simulators CST and HFSS. Moreover, the antenna is fabricated and it is used to measure the indoor RF spectrum in Egypt. A simple AC to DC converter unit is designed by using HSMS 2850 Schottky diode to convert the collected RF energy to DC energy. The antenna and the AC to DC converter are integrated to form the RF energy harvesting system. The maximum measured efficiency obtained at 2.4 GHz is about 63.7%. |
| Author(s): | N. A. Eltresy, D. M. Elsheakh, E. A. Abdallah, H. M. Elhennawy |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 12 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2516 KB |
| Title: | Power Containment of Hybrid Electromagnetic Modes of Cylindrical Dielectric Waveguide |
| File Type: | Conference Paper |
| Issue: | Volume: Numerical Techniques for Electromagnetic Applications Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 191 KB |
| Title: | Polarization Isolation Characteristics Between Two Center-Feed Single-Layer Waveguide Arrays Arranged Side-by-Side |
| Abstract: | Abstract - The near field coupling between two large alternating-phase fed single-layer waveguide arrays arranged side-by-side is analyzed by the Finite Element Method (FEM) (HFSS). First, the overall reflection as well as the radiation pattern from the array (320 slots and 18.4 λ x 14.9 λ) is analyzed, and excellent agreement with measurements is observed. Next, the isolation between two arrays is computed, and remarkable polarization isolations of more than 80 dB are predicted. The isolation is verified by measurements. The influence of the relative arrangement of the arrays upon the isolation is discussed. |
| Author(s): | Yasuhiro Tsunemitsu, Jiro Hirokawa, Makoto Ando, Yohei Miura, Yasuhiro Kazama, Naohisa Goto, Yasuhiro Tsunemitsu, Jiro Hirokawa, Makoto Ando, Yohei Miura, Yasuhiro Kazama, Naohisa Goto |
| File Type: | Journal Paper |
| Issue: | Volume: 21 Number: 3 Year: 2006 |
| Download Link: | Click here to download PDF File Size: 1538 KB |
| Title: | Planar Metamaterial for Matched Waveguide Termination |
| Abstract: | We present the design, fabrication, and characterization of a novel matched waveguide termination based on planar artificial metamaterial. This matched termination is realized by recent developed planar metamaterial absorber, which can be designed to near-completely absorb the propagating electromagnetic energy at the edge of a shorted rectangular waveguide. Theoretical discussions, numerical simulations and microwave experiments are employed to illustrate the matched characteristics of the proposed waveguide termination. As an example, a matched waveguide termination with standing wave ratio of 1.23 is experimentally demonstrated at microwave frequency. Our result yields a promising approach to design of novel waveguide terminations by techniques of metamaterials. |
| Author(s): | J. Li, F. Wang, G. Wen, Y. Huang, W. Zhu |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 12 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 458 KB |
| Title: | Physics of Wave Propagation in Miniaturized Metamaterial-based Waveguides: Analytical, Numerical and Experimental Investigation |
| File Type: | Conference Paper |
| Issue: | Volume: Metamaterial Structures with Application to Guided-Wave Electromagnetics and Antennas Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 462 KB |
| Title: | Perturbation Approach to Shape Reconstruction in a Rectangular Waveguide using Experimental Data |
| File Type: | Conference Paper |
| Issue: | Volume: S21 Optimization and Inverse Problems in Low-Frequency Electromagnetic Fields Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 558 KB |
| Title: | Performance Optimization of Reconfigurable Reflectarray Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: Latest Developments of Reflect/Transmit Array Antennas Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 657 KB |
| Title: | PERFORMANCE OF THE GENERALIZED MULTIPOLE TECHNIQUE (GMT/MMP) IN ANTENNA DESIGN AND OPTIMIZATION |
| Abstract: | During the last decade, the generalized multipole technique (GMT) has been extensively studied, improved and applied to many electromagnetics problems such as bioelectromagnetics, optics, waveguides and electromagnetic compatibility (EMC), but little has been reported towards utilizing this method for antenna design and optimization. On the other hand, the few published examples of simple dipoles and helices in the close vicinity of lossy scatterers have suggested the potential significance of GMT for antenna design purposes. In this paper, the applicability of the GMT based 3D multiple multipole (3D MMP) code for simulation of wire antenna has been investigated. To evaluate the advantages and limitations of 3D MMP, several basic types of wire antenna configurations were simulated. These were linear and linear array, helical, and physically constrained low profile antennas. To validate the method's performance, we calculated radiation patterns, impedance, return loss, reflection coefficient, VSWR, and compared them to available results from experiments and/or results published by others using different techniques. This investigation showed several conceptual advantages of this technique for antenna simulations. Furthermore, the thin-wire expansion in combination with multipoles and roof top functions provides a great degree of flexibility in modeling. The most recently implemented expansion, "line multipoles," extends the code's efficiency to non-thin-wire configurations (e.g., helix with small ratio of pitch to wire diameter). Critical issues of modeling are the feedpoint and wire tip area, matching point locations and segment length-to- diameter ratio. Symmetries are used where possible to minimize computation time without loss of generality as any antenna element may easily be assembled in non- symmetrical configurations with the block-iterative solver. In order to achieve better confidence on more complex configurations, extensive studies were performed to increase efficiency and stability of modeling and will be discussed. In addition, the numerical validation techniques were extended to satisfy the special requirements of antenna simulations. These studies demonstrate the potential of GMT/MMP for use in analysis, synthesis and optimization of antennas. [Vol. 9, No. 3 (1994), Special Issue on Generalized Multipole Technique (GMT), pp 79-89] |
| Author(s): | Roger Yew-Siow Tay, Niels Kuster, Roger Yew-Siow Tay, Niels Kuster |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 3 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 3160 KB |
| Title: | Particle Swarm Optimization Applied to EM Problems |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Electromagnetic Modeling by WIPL-D Software Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 339 KB |
| Title: | Parametric Model Generation Algorithm for Planar Microwave Structures based on Full–Wave analysis and Design of Experiment |
| File Type: | Conference Paper |
| Issue: | Volume: Time Domain Numerical Modeling Beyond FDTD Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 373 KB |
| Title: | Parametric Design of Open Ended Waveguide Array Feeder with Reflector Antenna for Switchable Cosecant-Squared Pattern |
| Abstract: | This paper presents parametric analysis of two-dimensional (2D) open-ended waveguide array feeder and introduces a modified parabolic reflector antenna structure to obtain electronically switchable radiation patterns. The main motivation of the study is to achieve desired radiation characteristics for naval, air and coastal surveillance radars such as, pencil beam, suppressed side lobes and cosecant-squared pattern shapes. The Analytical Regularization Method (ARM) is used as a fast and accurate predesign tool to compute near and far field radiation characteristics of the feeder and reflector antennas. The numerical procedure is initially verified by the analytical methods and the calculated results are presented for the proposed novel designs. |
| Author(s): | O. M. Yucedag, A. S. Turk |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 8 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 1297 KB |
| Title: | PARALLEL IMPLEMENTATION OF GALERKIN TECHNIQUE IN LARGE SCALE ELECTROMAGNETIC PROBLEMS |
| Abstract: | An intergal equation formulation in conjunction with a palallelised Galerkin technique is employed to solve large-scale electromagnetic (EM) problems. The proposed technique is applicable to EM structures consisting of similar conducting or dielectric parts, defined as "elements". Coupled intergal equations are derived in the frequency domain, written in terms of the conductivity currents or the electric fields deployed on the conducting or dielectric "elements" surfaces, respectively. The system of intergal equations is numerically solved via the parallel computed Galerkin technique, with convienient entire domain basis functions. Even for ellectrically large structures, the use of entire domain basis functions leads to relatively small order linear systems and the main computational cost refers to the matrix fill rather than the matrix solution. The parallalisation introduced to the computation of the matrix elements overcomes the limitation of using Method of Moments at lower and resonant frequencies. The inherent parallelisim of the introduced technique allows for the results to be obtained with minimal addition to sequental code programming effort. Two indicative electromagnetic compatibility applications are presented, concerning the coulping of incident waves with multiple conducting rectangular plates and the coupling phenomena occuring in a multi-element waveguide array looking into a layered lossy cylinder. Numerical results are presented, while the applicability/suitability of diverse High Performance Computing platforms is judged, based on both performance obtained and ease of code portation. |
| Author(s): | D.I. Kaklamani, K.S. Nikita, A. Marsh, D.I. Kaklamani, K.S. Nikita, A. Marsh |
| File Type: | Journal Paper |
| Issue: | Volume: 14 Number: 3 Year: 1999 |
| Download Link: | Click here to download PDF File Size: 808 KB |
| Title: | Padé Boundary Conditions for Finite Element Time Domain Beam Propagation Method |
| File Type: | Conference Paper |
| Issue: | Volume: S52 Novel Photonic Material and Devices II Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 347 KB |
| Title: | Overview of the Latest Additions to FEKO Suite 5.4 Enabling Faster Solutions to a Larger Variety of Electromagnetic Problems |
| File Type: | Conference Paper |
| Issue: | Volume: FEKO Modeling and Analysis I Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 231 KB |
| Title: | Optimum Design of SIW Longitudinal Slot Array Antennas with Specified Radiation Patterns |
| Abstract: | In this paper, an optimum design is presented for substrate integrated waveguide (SIW) longitudinal slot array antennas based on the method of least squares (MLS). Elliott’s design procedure for dielectric filled waveguides is considered, taking into account the internal and external mutual couplings. The MLS error function is a multi-term function based on design goals, including specified radiation patterns and matching of the input impedance. We use the hybrid method of genetic algorithm-conjugate gradient for the error function minimization. This approach is very effective because of combining the “pattern synthesis” with “impedance matching” and “calculation of array parameters”. This procedure increases the speed of design as well as synthesizing patterns with specified characteristics. The MLS design results and those obtained by HFSS and CST simulation software are in good agreement and verify the accuracy of the proposed method. |
| Author(s): | S. E. Hosseininejad, N. Komjani, H. Oraizim, M. T. Noghani |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 778 KB |
| Title: | Optimized Design of Substrate Integrated Waveguide Cavity based Oscillators |
| File Type: | Conference Paper |
| Issue: | Volume: Efficient Microwave Subsystem Design and Optimization Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 244 KB |
| Title: | Optimization of Aperiodic Waveguide Mode Converters |
| File Type: | Conference Paper |
| Issue: | Volume: CEM for Applied Analysis and Synthesis Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 294 KB |
| Title: | Optimal Design of Photonic Devices Using Time-Domain Beam Propagation Method |
| File Type: | Conference Paper |
| Issue: | Volume: S18 Time-Domain Techniques for Designing Electromagnetic and Optical Devices - I Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 552 KB |
| Title: | Optimal Design of Dielectric Layer PBG Filter Structure in Waveguide by Response Surface Methodology |
| File Type: | Conference Paper |
| Issue: | Volume: Efficient Optimization Techniques for High Frequency Structures Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 372 KB |
| Title: | Optimal Design of an Ultra-Wideband Antenna with the Irregular Shape on Radiator using Particle Swarm Optimization |
| Abstract: | An ultra-wideband antenna with an irregular shape radiator for ultra-wideband applications has been designed by particle swarm optimization along with the simulator, HFSS. The proposed antenna design process is automated. Also, the better results can be obtained efficiently. The proposed antenna is fed by a coplanar waveguide line. The optimized antenna has a compact substrate size of 34.0 mm by 33.35 mm. Results show that the optimized irregular shape of the proposed antenna outperforms the antennas with uniform rectangular shapes in impedance matching. The optimized antenna can cover the spectrum of ultra-wideband (3.1 GHz - 10.6 GHz). The current distributions are investigated for describing the antenna characteristics. Moreover, the proposed UWB antenna has good characteristics of radiation, transmission, and impedance bandwidth. |
| Author(s): | W. C. Weng |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 5 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 1271 KB |
| Title: | Optimal Design for an Ultra-wideband Antenna Using Particle Swarm Optimization |
| File Type: | Conference Paper |
| Issue: | Volume: Optimization Methods for EM Applications Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 1055 KB |
| Title: | Optical Crosstalk Improvement in Ring Resonator Based Add/Drop Multiplexers Using Controllable Reflectivity |
| Abstract: | In this paper, the topic of optical signal integrity is approached by studying crosstalk suppression in ring resonator based optical Add/Drop Multiplexers (OADM). The resonance splitting induced by surface corrugation is exploited to enhance signal integrity by increasing the crosstalk suppression bandwidth compared to that of a smooth-walled resonator. Sidewall roughness in silicon-on-insulator waveguides is studied using Coupled Mode Theory (time and space domain CMT). An analytical model of a corrugated ring resonator is presented, which is then exploited to estimate the spectral response of the different ports. Verification against results generated from full-wave electromagnetic numerical modeling of a randomized corrugated ring is performed. The analysis then examines the performance of an OADM with controllable reflectivity resulting from a predefined corrugation of sidewall. Gratings have been successfully used in optical filters; this paper proposes the use of a grating in an OADM, giving more controlled roughness. A grating-assisted design of a single ring OADM with 28 GHz crosstalk suppression bandwidth is presented. This bandwidth supports the dropping of 10 Gbps signals with mitigated crosstalk levels and improved signal integrity. |
| Author(s): | R. D. Mansoor, A. P. Duffy |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 10 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2913 KB |
| Title: | ON THE USE OF BIVARIATE SPLINE INTERPOLATION OF SLOT DATA IN THE DESIGN OF SLOTTED WAVEGUIDE ARRAYS |
| Abstract: | Essential to the design process of slotted waveguide arrays is an accurate knowledge of the self-properties of the individual slots. These properties can be computed with sufficient accuracy using moment method codes, which are too computationally intensive to be incorporated into design codes for large arrays. This paper describes an interpolation scheme which provides both sufficiently accurate, and rapid, computation of slot data from a pre-determined database to be viable for use in a slotted waveguide array design code. [Vol. 9, No. 1 (1994), pp 6-9] |
| Author(s): | Derek A. McNamara, Johan Joubert, Derek A. McNamara, Johan Joubert |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 1 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 335 KB |
| Title: | On the Power Containment of Transverse Electromagnetic Modes of Cylindrical Dielectric Waveguide |
| File Type: | Conference Paper |
| Issue: | Volume: Application of Electromagnetic Simulation for Designing and Analysis of Antennas and Radio Propagations Part II Number: Year: 2014 |
| Download Link: | Login To Download (For Members) File Size: 206 KB |
| Title: | On The Capacity of the Waveguide Indoor MIMO Channel |
| File Type: | Conference Paper |
| Issue: | Volume: Poster Sessions 1 Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 86 KB |
| Title: | Numerical Analysis of Parallel Plate Waveguide Loaded with Magnetic Photonic Crystals (MPC\'s) |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling Methods for Metamaterials Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 294 KB |
| Title: | Novel High Performance Low Cost Phase Shifters Design Based on the Ferroelectric Materials Technology Using the WIPL-D Code |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling Using WIPL-D Code(I) Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 174 KB |
| Title: | Novel Compact Substrate Integrated Waveguide Balun Filter and Balanced Filter |
| File Type: | Conference Paper |
| Issue: | Volume: 3-MA-2 Novel Multi-functional Integrated Microwave Circuits and Components Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 392 KB |
| Title: | Novel Broadband Circularly Polarized Monopole Antenna for Multi-communication Systems |
| Abstract: | This paper proposes a novel coplanar waveguide (CPW) fed broadband circularly polarized (CP) monopole antenna, which applies to C-band and various wireless communication systems. The antenna consists of the double circular-shaped patch (DCSP) with square and L-shaped slots, and an improved asymmetric ground plane. The prototype of the designed antenna has been fabricated. The results of the measurement show that the 10-dB impedance bandwidth (ZBW) is 117.8% (2.2–8.5 GHz), the 3-dB axial ratio bandwidth (ARBW) is 62% (4.45–8.45 GHz). |
| Author(s): | H. Chen, Q. Feng, Y. Wen, Q. Fu |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 10 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1257 KB |
| Title: | Nondestructive Clamped-Waveguide Low-loss Material Extraction Technique |
| File Type: | Conference Paper |
| Issue: | Volume: Nondestructive Evaluation and Materials Characterization Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 312 KB |
| Title: | Non-destructive Testing on Length of Steel Pipelines Partially Embedded in Land Surface |
| File Type: | Conference Paper |
| Issue: | Volume: S17 Electromagnetic Non-destructive Evaluation Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 217 KB |
| Title: | New Implementations of Complete Radiation Boundary Conditions for Maxwell’s Equations |
| File Type: | Conference Paper |
| Issue: | Volume: S22 Advanced Numerical Methods for Electromagnetic Analysis Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 87 KB |
| Title: | New FEKO Modeling Capabilities: Waveguide Ports with Dielectrics, Fast MLFMM based Near-Field Calculations, Integrated Network Modeling, and Dielectric GO |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling using FEKO – I Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 538 KB |
| Title: | Neural Network Technique Simultaneously Optimizing Antenna Return Loss and Radiation Pattern |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling with QuickWave/Concerto Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 138 KB |
| Title: | Neural Network Inverse Modeling Methods for Fast and Accurate Solution of Electromagnetic Devices |
| File Type: | Conference Paper |
| Issue: | Volume: Microwave Modeling and CAD Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 61 KB |
| Title: | Narrow Band, Sharp Roll-Off Rejection Frequency Selective Surface Based on Substrate Integrated Waveguide |
| Abstract: | In this paper, a novel frequency selective surface which has a narrower passband and sharper rolloff rejection than the other single layer designs, is presented. Also, it has better independency from angle and polarization of incident plane wave. In this design a ring loop is placed on a cylindrical cavity of substrate integrated waveguide (SIW). Because of the most compatibility between loop and the electric fields of cylindrical cavity, minimum insertion loss and narrow passband are achieved. |
| Author(s): | M. S. Samani, R. S. Shirazi, G. Moradi |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 630 KB |
| Title: | Multipactor in Dual-Mode Elliptical Waveguide |
| File Type: | Conference Paper |
| Issue: | Volume: S23 RF/Microwave Electromagnetics - Computational Modeling and Experiments Number: Year: 2015 |
| Download Link: | Login To Download (For Members) File Size: 94 KB |
| Title: | Multilayer Half-Mode Substrate Integrated Waveguide Wideband Coupler with High Selectivity |
| Abstract: | A novel 3dB wideband coupler with enhanced selectivity has been proposed and developed in multilayer HMSIW topology. Periodic ginkgo leaf slots (GLS) are etched on top layer of HMSIW to realize a pass-band combining with high-pass characteristics of HMSIW. The novel GLS cells have stop-band characteristics aiming to improve the frequency selectivity and extend the upper stop-band. Moreover, the roll-off at the upper side is very sharper. A continuous coupling slot is etched in the conductor layer at the broadwall of HMSIW. Coupling takes place through the long, offset slot, which features a flexible design providing a wide coupling dynamic range with wideband characteristics. Detailed design process is introduced to synthesize a wideband filtering HMSIW coupler with better stopband rejection. The novel coupler is showing a 34.9% coupling bandwidth at 8.87 GHz with good isolation, reflection and out-of-band rejection performances. Its stop band is from 13.8 to 17.6GHz with the rejection more than 40dB. Good agreement is obtained between the simulated and measured results of the proposed structure. |
| Author(s): | Z. Zhang, Y. Fan, Y. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 9 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1772 KB |
| Title: | Multi-Slot Antenna for Radar Systems |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Antenna Applications Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 220 KB |
| Title: | Multi-Beams Waveguide Slot Antennas at X-Band for Wireless Communications Systems |
| Abstract: | This paper focuses on the design of a multibeams antenna using waveguide slots technology at Xband. The multi-beams radiation is proposed to expand the coverage of the single antenna, thus more capacity is enabled. Waveguide slots antenna is a well-known antenna for high power and gain transmission capabilities. Therefore, it is preferred. In this work, four variations of waveguide slots antennas are studied. The slot distribution covers one to four broad and narrow walls of the waveguide. This technique enables multibeams patterns. The performance of the proposed antennas is simulated using CST microwave software. The simulated responses of the antennas show that a good matched with return loss greater than 10 dB at the desired frequency. The four proposed antennas achieved a good gain between 6.3 and 7.4 dB with directional beamwidth of 15 degree. The proposed antennas are suitable for implementing in radar applications. |
| Author(s): | H. O. Hanoosh, M. K. A. Rahim, N. A. Murad, Y. M. Hussein |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 7 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1945 KB |
| Title: | Multi-Bandwidth CPW-Fed Open End Square Loop Monopole Antenna for Energy Harvesting |
| Abstract: | Compact CPW-fed open end square loop monopole antenna is presented. The antenna can harvest ambient power at different radio frequencies of 1.8, 1.9, 2.4 and 5.2 GHz. The multi-band coplanar waveguide antenna (MCPW) is designed and fabricated on a very thin and lowprofile substrate. The proposed antenna is used to measure the ambient spectrum in two different places. One of them is indoor and the other is outdoor, in order to see the effect of the place on the proposed energy harvesting system. A multi-band rectifier circuit is designed and integrated with the proposed antenna. The maximum simulation efficiency is 60.98% at 1.9 GHz and -1 dBm input power. The maximum measured efficiency is 60.57% at 2.5 GHz and -1 dBm RF received power. Also, the proposed rectenna has 53.1% measured efficiency at 2.5 GHz and RF received power of -5 dBm. |
| Author(s): | N. Eltresy, D. Elsheakh, E. Abdallah, H. Elhenawy |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 2 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1550 KB |
| Title: | Multi-Bandwidth CPW-Fed Open End Square Loop Monopole Antenna for Energy Harvesting |
| File Type: | Conference Paper |
| Issue: | Volume: S42 Wireless Implants for Biomedical Telemetry II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 289 KB |
| Title: | Modified V-Groove Slot Waveguide for DNA Hybridization Detection |
| Abstract: | Highly sensitive slot waveguides are introduced and studied for DNA hybridization detection. In this investigation, two different configurations based on V-groove silicon on insulator (SOI) waveguides are analyzed using full vectorial finite element method. The suggested designs rely on improving the light confinement through the slot region at an operating wavelength of 1.55 μm. The power confinement, power density (PD), and effective index of the supported modes are studied for the conventional rectangular slot waveguide and proposed designs. Further, the effect of adding a plasmonic layer to the reported slot waveguides is implemented. It has been shown that the plasmonic layer increases the light confinement in the slot region with high potential for DNA hybridization detection with good confinement through the slot region. |
| Author(s): | E. ELDamarawy, A. M. Heikal, S. S. A. Obayya, M. F. O. Hameed |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 7 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 2255 KB |
| Title: | MODIFIED REFLECTIVE SYMMETRIES FOR IMPROVING THE EFFICIENCY OF THE MMP CODES |
| Abstract: | A more general concept for the treatment of symmetry in the 3D MMP codes allows considerable gains in usability. Up to now, symmetry decomposition of functions has been made with functions that are continuous across the symmetry plane. Now discontinuous symmetrizations are added. Possible continuity conditions in the symmetry plane can be enforced explicitly with matching points. Not only are problem sizes reduced, but the creation of good models in the MMP sense is considerably simplified in some common applications. The improved approach also illustrates some of the "classical" methods for calculating obstacles in waveguides. [Vol. 9, No. 3 (1994), Special Issue on Generalized Multipole Technique (GMT), pp 57-62] |
| Author(s): | Fin O. Bomholt, Lars H. Bomholt, Fin O. Bomholt, Lars H. Bomholt |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 3 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 483 KB |
| Title: | Modified Broadband Half Mode Substrate Integrated Waveguide Cruciform Coupler |
| Abstract: | In this paper, a cruciform coupler with Half Mode Substrate Integrated Waveguide (HMSIW) structure is presented. The prototype coupler consists of four half mode SIW structures, which are crossing each other at right angles. Also, two metallic posts are inserted in free section of junction in order to make coupling properties. Compact size and broadband operation are the features of this coupler. The size of coupler is reduced 24% in comparison to previous HMSIW cruciform couplers. A fractional bandwidth of about 35% is obtained. The coupler is designed and simulated by HFSS13. Here, the simulation results are compared with experimental results. |
| Author(s): | Z. Mansouri, M. Kishihara, F. B. Zarrabi, F. Geran |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 11 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 522 KB |
| Title: | Modification of Vivaldi Antenna for 2-18 GHz UWB Application with Substrate Integration Waveguide Structure and Comb Slots |
| Abstract: | In this paper have been developed two new Vivaldi antenna for UWB application at 2-18 GHz with SIW structure for linear phase center labeled as antenna I and antenna II. The proposed antennas have high gain and directional patterns with symmetric radiation pattern in phi=0 and phi=90 planes. The SIW structure is combined with Vivaldi antenna in order to improve the gain, pattern and phase center linearity. Similarly, for gain improvement at lower frequencies for SIW antenna and with less divergence in the gain, slots with comb models are proposed. The prototype antenna is printed and fabricated on Roger 4003 with ?r = 3.45 and thickness of 1.5 mm. The antenna’s total dimension is 120 mm × 160 mm. The simulation and experimental VSWR and the gain of antenna I and II is less than 2.5 and 6 dBi - 15 dBi, and 2.4 for 2.17-18 GHz and 8.2 dBi - 15.5 dBi in the entire frequency range of 2-18 GHz respectively. Likewise, the Vivaldi antenna phase center is investigated and finally the linear characteristic of the antenna phase center is presented with linear variation. |
| Author(s): | F. B. Zarrabi, N. P. Gandji, R. Ahmadian, H. Kuhestani, Z. Mansouri |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 8 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 951 KB |
| Title: | Modelling Nonlinear Photonics Crystal Waveguides Using the Transmission Line Modelling Method |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Transmission-Line Matrix (TLM) Analysis Methods Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 277 KB |
| Title: | Modelling and Impact of 3D Print Inaccuracies on the Performance of Circular Waveguide Hybrid Coupler |
| File Type: | Conference Paper |
| Issue: | Volume: S22 Advances in Hybrid Material Additive Manufacturing of Antennas Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 445 KB |
| Title: | Modelling and Impact of 3D Print Inaccuracies on the Performance of Circular Waveguide Hybrid Coupler |
| Abstract: | Circular waveguide hybrid coupler operating over a frequency range of ISM 57-64 GHz, additively printed and metal plated using electroless technique is introduced. Effects of orientation of print and thickness of intricate structures on the performance of circular waveguide hybrid coupler are presented. The structure is printed using commercially available stereolithographic (SLA) printer. Circulatory system operated by a peristaltic pump is used for selective silver deposition of the hybrid coupler. |
| Author(s): | A. Bal, G. H. Huff |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1420 KB |
| Title: | Modeling the RF Performance of a Small Array |
| Abstract: | ABSTRACT - Large phased arrays can be reasonably accurately modelled in finite element programs, such as HFSS using an infinite array model of the embedded element. This approximation is not applicable to small arrays, where each element is in a different electromagnetic environment. Very small arrays of simple elements (of about 10 elements or less) can be modelled as a complete unit, but slightly larger or more complex arrays require additional techniques to be modelled accurately. The predicted performance of several versions of a small array has been compared using HFSS V9.5. The arrays contained either waveguide or printed dipole elements and, within the limits of available computing resources, solutions were generated for (1) complete array models, (2) half and quarter array models with symmetry planes, and (3) infinite array models. |
| Author(s): | P. Foster, A. Wicks, P. Foster, A. Wicks |
| File Type: | Journal Paper |
| Issue: | Volume: 21 Number: 3 Year: 2006 |
| Download Link: | Click here to download PDF File Size: 366 KB |
| Title: | Modeling of Photonic Waveguide for Biosensing |
| File Type: | Conference Paper |
| Issue: | Volume: Low Frequency Applications - 2 Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 196 KB |
| Title: | Modeling Nonlinear Interactions Between RF And Optical Fields In Traveling Wave Modulators Using A Hybrid Approach |
| File Type: | Conference Paper |
| Issue: | Volume: New Techniques for Computational Electromagnetic Validation Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 302 KB |
| Title: | Modeling and Realization of Cavity-Backed Dual Band SIW Antenna |
| Abstract: | Herein, substrate integrated waveguide technology is applied in order to design high performance dual-band microstrip patch antennas. Two microstrip patch antenna designs were studied and modeled in 3D electromagnetic simulators. The obtained optimal models were then realized and measured. The measurement performance of the proposed antenna designs were then measured for 2.4 and 5.6 GHz. The results suggest that the proposed model consisting of a modified microstrip cavity-backed antenna and a defected ground structure is a high performance and low cost solution for 2.4 and 5.6 GHz applications. |
| Author(s): | M. A. Belen, P. Mahouti, A. Caliskan, A. Belen |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 11 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1822 KB |
| Title: | Modeling and Analysis of a Dual-Band Dual-Polarization Radiator Using FEKO |
| File Type: | Conference Paper |
| Issue: | Volume: FEKO Modeling and Analysis - 1 Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 200 KB |
| Title: | Model Validation for a Waveguide Septum Polarizer |
| File Type: | Conference Paper |
| Issue: | Volume: FEKO Modeling and Analysis III Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 734 KB |
| Title: | Mode-Selective Corrugated Substrate Integrated Waveguide: A New SIW Transmission Line |
| File Type: | Conference Paper |
| Issue: | Volume: 6-ME-2 Broadband and Multiband RF Circuits II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 313 KB |
| Title: | Mode Conversion Caused by Bending in Photonic Subwavelength Waveguides |
| Abstract: | We study the propagation of light in a subwavelength planar waveguide with an angular bend. We observe the mode conversion of a guided wave with a symmetric beam profile impinging into the bending of a waveguide. The guided wave outgoing from the bend is a mixed set of symmetric and asymmetric modes. The amount of mode conversion through the bend is quantified by calculating the Fourier transform of the electric field profile. It is found that the conversion rate is a function of the bending angle. |
| Author(s): | Y. J. Rodriguez-Viveros, D. Moctezuma-Enriquez, P. Castro-Garay, B. Manzanares-Martinez, C. I. Ham-Rodriguez, E. Urrutia-Banuelos, J. Manzanares-Martinez |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 12 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 708 KB |
| Title: | Mode Analysis of Waveguides in Layered Media |
| File Type: | Conference Paper |
| Issue: | Volume: S47 Integral Equation Solvers for Real-Life Applications I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 255 KB |
| Title: | Modal Analysis of Wave Propagation in Straight and Curved Arched Tunnel Based on Equivalent Rectangular Tunnel Model |
| Abstract: | In this paper, a model is presented to simulate wave propagation in straight and curved tunnels with arched cross section with imperfectly conducting walls. The model is based on treating the tunnels as a rectangular waveguide with imperfectly conducting walls, where the arched cross section of the tunnels is approximated with equivalent rectangular cross section. A scenario is considered to check the accuracy of this model. This scenario is verified by comparing experimental and numerical simulation results. Good agreement between the proposed model and the experimental results is obtained. |
| Author(s): | H. M. El-Maghrabi, S. F. Mahmoud, M. El-Said |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 9 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1770 KB |
| Title: | Modal Analysis for a Waveguide of Nanorods Using the Field Computation for a Chain of Finite Length |
| Abstract: | The propagation of light along an infinite 2D chain of silver nanorods is analyzed and the dispersion for this waveguide is computed using field computation for a finite chain of nanorods. In this work, generalized multipole technique is used for the analysis. This method calculates the imaginary and real parts of the propagation constant by exciting the chain in one end and observing propagation of modes along the chain far enough from the excitation. It is shown that a short chain of finite length is sufficient for the calculation of the phase constant while the attenuation constant requires a longer chain. Field distribution is depicted for even and odd modes and it is shown that in the simulated frequency range only two modes can be excited and can propagate along the waveguide. |
| Author(s): | Y. Rahbarihagh, F. Kalhor, J. Rashed-Mohassel, M. Shahabadi |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 2114 KB |
| Title: | Microwave/Millimeter Wave Metamaterial Development Using the Design of Experiments Technique |
| File Type: | Conference Paper |
| Issue: | Volume: Metamaterials Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 140 KB |
| Title: | Method of Moments Solution of Closed Chirowaveguides |
| File Type: | Conference Paper |
| Issue: | Volume: Guided Waves in Non-Standard Media Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 169 KB |
| Title: | Method of Moments (MoM) Modeling of Wave Propagation Inside a Wedge |
| Abstract: | Method of Moments (MoM) is used to model guided wave propagation inside a nonpenetrable wedge waveguide and the results are validated against analytical mode-based exact solutions. |
| Author(s): | G. Apaydin, L. Sevgi |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 884 KB |
| Title: | Method of Moments (MoM) Modeling for Resonating Structures: Propagation inside a Parallel Plate Waveguide |
| Abstract: | Method of Moments (MoM) modeling inside resonating structures is discussed and a novel approach called Multi-MoM (Mi-MoM) is proposed. Propagation inside a two-dimensional (2D) non-penetrable parallel plate waveguide is taken into account. The Mi-MoM results are compared with the analytical reference solution. Practical ways of different source representations (untilted/tilted Gaussian beams) are also presented. Finally, surface irregularities inside the waveguide and their effects on the propagation are modeled with both Mi-MoM and the Split-Step Parabolic Equation (SSPE) method. |
| Author(s): | G. Apaydin, L. Sevgi |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 10 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 2721 KB |
| Title: | Measurement of Electromagnetic Parameters Based on Gap-Waveguide Structure |
| File Type: | Conference Paper |
| Issue: | Volume: 1-SP-4 Metasurfaces/Metamaterials Theory, Design and Applications I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 574 KB |
| Title: | Mathieu functions of complex arguments and thier applications to the scattering by lossy elliptic cylinders |
| Abstract: | The aim of this paper is to outline the theory for calculating the angular and radial Mathieu functions of complex arguments. These functions are required for the computation of analytic solutions of electromagnetic scattering by lossy dielectric elliptic cylinders and waveguides. The backscattered echo width of a lossy dielectric elliptic cylinder is compared with the special case of lossy circular and weakly lossy elliptic cylinders and excellent agreement is obtained in all cases. Tabulated and plotted numerical results of Mathieu functions are presented. |
| Author(s): | Abdul-kadir Hamid, M.I. Hussein, H. A. Ragheb, M. Hamid, Abdul-kadir Hamid, M.I. Hussein, H. A. Ragheb, M. Hamid |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 3 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 391 KB |
| Title: | Manipulation of Electromagnetic Waves Based on New Unique Metamaterials: Theory & Applications |
| Abstract: | Metamaterials are typically engineered by arranging a set of unit cells in a regular array throughout a region of space, thus, obtaining some desirable macroscopic electromagnetic behavior. The desired property is often one that is not normally found naturally (negative refractive index, near-zero index, etc.). Over the past few years, the flexibilities of the metamaterials in choosing the numerical value of the effective permittivity or permeability have led to kinds of novel theoretical and practical possibilities for different applications, ranging from microwave to optical regime. In this paper, the theoretical mechanism for constructing metamaterials is described, and the unique feature of electromagnetic waves can be manipulated is verified by their applicability to construct various devices or components Some typical application is given, including: (1) novel RF devices realized by optical transformation principle, such as energy concentrators and universal waveguide connectors; (2) metamaterial-based wave absorbers; (3) gain enhancement approach of aperture antennas by planar metamaterial lenses loaded; (4) ultra-thin lenses with dual-polarization filtering features; and (5) beam tunable antennas by metamaterial device. Undoubtely, the reported results suggest promising applications in the next-generation communication system. |
| Author(s): | Q. Qu, K. Zhang, G. H. Yang |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 12 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 2466 KB |
| Title: | Low-Loss Wireless Implant Telemetry Using Magnetoinductive Waveguides |
| File Type: | Conference Paper |
| Issue: | Volume: S06 Student Paper Competition Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 388 KB |
| Title: | Low-Loss Wireless Implant Telemetry Using Magnetoinductive Waveguides |
| File Type: | Conference Paper |
| Issue: | Volume: S07 Biomedical Applications - II Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 388 KB |
| Title: | Low-cost Two-layer Terahertz Transmitarray |
| File Type: | Conference Paper |
| Issue: | Volume: 2-2-B Millimeter Wave and Terahertz Antennas Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 264 KB |
| Title: | Low Sidelobe Leaky Wave Antenna Based on Gap Waveguide Technology |
| File Type: | Conference Paper |
| Issue: | Volume: 4-P4-D Millimeter-Wave GAP Waveguide Technology Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 382 KB |
| Title: | Low Side-Lobe Substrate Integrated Cavity Antenna Array Using Unequal Microstrip-Ridge Gap Waveguide Feeding Network at 94 GHz |
| File Type: | Conference Paper |
| Issue: | Volume: 4-P4-D Millimeter-Wave GAP Waveguide Technology Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 975 KB |
| Title: | Low Frequency Signal Generation during Fano Resonance Build-up Process |
| File Type: | Conference Paper |
| Issue: | Volume: S31 Electromagnetic/Thermal Modeling of Infrared/Optical Antennas Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 520 KB |
| Title: | Loss Analysis of Wideband RF MEMS Shunt Capacitive Switch in T and Pi-Match Configurations |
| Abstract: | A wide bandwidth coplanar-waveguide (CPW) based RF MEMS capacitive shunt switch with pi-matched & T-matched having high impedance transmission lines is designed and simulated for broadband (18-40 GHz) application. The effects of variation in membrane width (50 & 70 mu m) of the switch and high-impedance transmission line length (300 – 600 mu m) between the switch structures on scattering parameters are studied. The variation in beam width has very little effect on return loss of the switch in up-state. The reduction in high-impedance transmission line length yields marginal improvement in return loss. In the down-state configuration, the return loss showed negligible change with the variation in beam width and high-impedance transmission line length. The isolation is found improved with the increase in beam width and high-impedance transmission line length in whole frequency range. Simulating the technical performance demonstrates the greater improvement in RF characteristics of the switch particularly in return loss in up-state position. In order to validate the obtained result, Artificial Neural Network (ANN) has been trained using ADS result. Comparison shows good agreement between ADS and ANN results. |
| Author(s): | S. Suganthi, P. Thiruvalar Selvan, S. Raghavan |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 9 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1832 KB |
| Title: | Localized Plasmonic Enhanced Waveguide Modulator with High Speed Tunability Using Graphene |
| File Type: | Conference Paper |
| Issue: | Volume: 3-MA-4 EM Characteristic and Application of Graphene Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 424 KB |
| Title: | Liquid Crystal-Based Dielectric-Loaded Plasmonic Ring Resonator Filter |
| Abstract: | A new tunable plasmonic filter based on liquid crystal dielectric loaded plasmonic waveguide is proposed and studied. |
| Author(s): | S. M. Alavi, H. Armand |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 2 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 697 KB |
| Title: | LF Sky Wave Propagation Excited by a Horizontal Electric Dipole Towards Understanding of Its Radiation Mechanism |
| Abstract: | In this paper, the electromagnetic pulses have been investigated based on the theory of wave-hop propagation. The approximate formulas are obtained for the electromagnetic field of a vertical magnetic dipole in the presence of an Earth-ionosphere waveguide. Based on the results obtained, the approximate formulas are derived readily for the ground wave and sky waves due to horizontal electric dipole excitation by using a reciprocity theorem. The corresponding computations and discussions are carried out specifically by analogy with those generated by a vertical electric dipole with the formulas in CCIR’s recommendation. It is shown that the sky wave pulses would interfere at certain distances and occur by different time-delays. |
| Author(s): | H. Xu, T. Gu, J. Zheng, K. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 6 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2695 KB |
| Title: | Late-time Instability in Finite Difference Modeling of Very-Low-Frequency Propagation in the Earth-Ionosphere Waveguide |
| File Type: | Conference Paper |
| Issue: | Volume: S39 Modeling Electromagnetic Waves in Plasma Environments Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 1677 KB |
| Title: | Large Waveguide Slotted Array With Shaped Patterns |
| File Type: | Conference Paper |
| Issue: | Volume: S36 Antennas and Arrays Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 290 KB |
| Title: | Ka-band Planar H-plane Horn Array with Reduced Sidelobe Level |
| File Type: | Conference Paper |
| Issue: | Volume: 2-SE-1 Antennas for mmWave/THz and 5G Communications II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 499 KB |
| Title: | Ka-band Planar H-plane Horn Antenna Based on the Concept of Complementary Source |
| File Type: | Conference Paper |
| Issue: | Volume: 1-P1-A Student Paper Contest Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 203 KB |
| Title: | Investigations on Corrugation Issues in SIW based Antipodal Linear Tapered Slot Antenna for Wireless Networks at 60 GHz |
| Abstract: | In recent days, substrate integrated waveguide (SIW) technology is attracting a lot of interest in the development of millimeter-wave (MmW) based circuits due to its inherent advantages. Tapered slot antenna (TSA) with antipodal geometry is used to surmount the impedance matching constraint and to enhance electrical performance including gain, side lobes levels, and main beam pattern. This paper focuses on the design of antipodal linear tapered slot antenna (ALTSA) using SIW technique at 60 GHz for wireless local area network (WLAN) and wireless personal area network (WPAN) applications. The size of the proposed antenna is very compact (43.29 mm × 9.93 mm × 0.381 mm) and the substrate used is RT/ Duroid 5880. Corrugations have been investigated on both the edges to improve antenna gain, front-to-back ratio, and radiation patterns. Numerical simulations are performed using 3D-EM tools, high frequency structure simulator (HFSS) and CST microwave studio (CST MWS). The obtained results reveal that when corrugation is introduced in the antenna there is a significant improvement of 3 dB in gain, respectively. This study has been reported earlier in other frequency bands but rarely any literature has been reported of such development at 60 GHz. |
| Author(s): | P. Shrivastava, D. Chandra, N. Tiwari, T. Rama Rao |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 10 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 4334 KB |
| Title: | Investigation of an Explicit, Residual-Based, a Posteriori Error Indicator for the Adaptive Finite Element Analysis of Waveguide Structures |
| Abstract: | The performance of an explicit, residual-based, a posteriori error indicator for directing a single level p-refinement of the finite element method, electromagnetic analysis of multiport waveguide structures is evaluated experimentally by considering three different structures. The error indicator consists of a linear combination of element volume and element face residuals. It is found that the indicator is generally very effective in identifying elements that need to be refined. It is also found that the relative weighting of the volume and face residual contributions to the error indicator plays an important role in its performance. |
| Author(s): | Matthys M. Botha, David B. Davidson, Matthys M. Botha, David B. Davidson |
| File Type: | Journal Paper |
| Issue: | Volume: 21 Number: 1 Year: 2006 |
| Download Link: | Click here to download PDF File Size: 251 KB |
| Title: | Integrated Simulation and Analysis of Super Large Slotted Waveguide Array |
| Abstract: | Aiming at the simulation problem of the super large slotted waveguide array antenna, the parallel higher-order method of moment is used and the coupling effect between each slot element is taken into account to perform the integrated and accurate simulation. In order to ensure that the algorithm is efficient and stable in the parallel process, the BDPLU strategy is introduced to reduce the communication pressure and eliminates the redundant communication of the equation solving when pivoting, which speeds up the process of matrix equation solving. According to different types of waveguide port forms, the computation of rectangular wave port and coaxial wave port is studied, and a new parallel matrix filling technique of wave port is used to accelerate the matrix filling process. Numerical examples calculated at "Tianhe-2" supercomputer show that the algorithm can efficiently and accurately handle the simulation analysis of most types of complex slotted waveguide array. |
| Author(s): | C. Zhai, Y. Liu, S. Jiang, Z. Lin, X. Zhao |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 7 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1839 KB |
| Title: | Integrated Disc-loaded Monopole Array Antenna and the Small PIFA Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: Analysis and Design of Antennas for Wireless Communications Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 263 KB |
| Title: | Integral equation formulation for the impedance representation of aperture-coupled devices with finite wall conductivity |
| File Type: | Conference Paper |
| Issue: | Volume: Special Session: Recent Electromagnetics & Antennas Activities in the European Network "ACE" Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 326 KB |
| Title: | Indoor Wave Propagation Prediction for Corridors Segments with Partially Reflecting Walls by Using 3D Waveguide Modal Analysis |
| Abstract: | In this paper, a model is presented to simulate wave propagation in indoor corridors with partially reflecting walls. The model is based on combination of modal analysis, dyadic Green’s function, mode matching method and generalized scattering matrix. A new approach to simulate the effect of partial reflectivity of the walls of the waveguide model is proposed. This approach is based on approximating the fields inside the space of the actual waveguide section by equivalent waveguide sections of larger dimensions with PEC (Perfect Electric Conductor) walls. A simple scenario is considered in order to check the accuracy of this model. This scenario is verified by comparing experimental and numerical simulation results. The obtained results show that the proposed model is suitable for predicting accurate electric field strength due to an electromagnetic source in an indoor environment with partially reflecting boundaries. |
| Author(s): | H. M. El-Maghrabi, A. M. Attiya, E. A. Hashish |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 3 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 871 KB |
| Title: | IMPROVED MODELING OF SHARP ZONES IN RESONANT PROBLEMS WITH THE TLM METHOD |
| Abstract: | Several new modified nodes based on the symmetrical condensed node with stubs are proposed to solve the difficulty of the TLM method in modeling problems highly dependent on frequency. These nodes avoid the problem of indirect modeling at critical points, such as bends and corners, thus providing more accurate results and flexibility in the modeling of conducting parts. The new nodes are applied to specific problems of rectangular waveguides loaded with rectangular irises of finite width to verify their capability to predict resonant phenomena. |
| Author(s): | J. A. Morente, J.A. Porti, H. Magan, O. Torres, J. A. Morente, J.A. Porti, H. Magan, O. Torres |
| File Type: | Journal Paper |
| Issue: | Volume: 14 Number: 2 Year: 1999 |
| Download Link: | Click here to download PDF File Size: 413 KB |
| Title: | Improved Heating Uniformity of a 3-kWatt 2.45GHz Microwave Dryer Using Multiple Multi-Slotted Waveguides |
| File Type: | Conference Paper |
| Issue: | Volume: S26 Advances on Time Domain Modeling and Design II Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 352 KB |
| Title: | Hyperthermia treatment modeling: is prescriptive, quantitative SAR dosimetry to be preferred over thermal dosimetry? |
| File Type: | Conference Paper |
| Issue: | Volume: Computational RF and Thermal Dosimetry Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 192 KB |
| Title: | Hyperthermia Study in Cancer Treatment |
| File Type: | Conference Paper |
| Issue: | Volume: S52 Biomedical Applications Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 351 KB |
| Title: | Hybrid Plasmonic Waveguiding Model in a V-shaped Silicon Groove |
| Abstract: | A modified V-shaped silicon groove waveguide, embeded with metal nanowire,which is coated with a low refractive index layer was proposed. Finite element method (FEM) is used to numerically simulate the characteristics of the hybrid plasmonic mode at the wavelength of 1550nm. The simulation results show that the hybrid plasmonic mode can be confined to the dielectric layer on the surface of the metal nanowire. Meanwhile, factors on the modal properties are analyzed. Low loss and strong mode confinement can be realized by adjusting the size of the dielectric and metal nanowires as well as the angle of the V-shaped groove. The overall performance of the proposed model is superior to that of traditional hybrid plasmonic waveguides. |
| Author(s): | X.-J. Kuang, Z.-X. Huang, X.-Y. Cao, M. Kong, J. Shen, X.-L. Wu |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 6 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1668 KB |
| Title: | Hybrid of Moment Method and Mode Matching Technique for Full-Wave Analysis of SIW Circuits |
| Abstract: | In this paper, a full wave analysis of substrate integrated waveguide (SIW) structures is presented based on the moment method in combination with the mode matching technique. Initially, input and output post pairs are terminated with two waveguide sections. Then waveguide width, as an unknown variable, is adjusted to obtain minimum reflection from the SIW. Field distribution in the structure and current density on posts as well as dispersion characteristic of the SIW are investigated. Also, by taking the advantage of the moment method, analysis of the structures with longitudinal discontinuity along the wave propagation direction is offered. Furthermore, versatile instances are analyzed and compared with experimental values, results from high frequency structure simulator (HFSS), and numerical methods in recent literature. Good agreement between the results verifies the accuracy of the hybrid method. |
| Author(s): | R. Rezaiesarlak, M. Salehi, E. Mehrshahi |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 8 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 842 KB |
| Title: | Hybrid Nonlinear and Electromagnetic Design of an Active Oscillator SIW Cavity Backed Slot Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Student Paper Competition Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 623 KB |
| Title: | Hybrid Nonlinear and Electromagnetic Design of an Active Oscillator SIW Cavity Backed Slot Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Efficient Microwave Subsystem Design and Optimization Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 216 KB |
| Title: | Using FEKO Software for Analysis of Radiated Electric Field by Power Converters |
| File Type: | Conference Paper |
| Issue: | Volume: FEKO Modeling and Analysis - 2 Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 336 KB |
| Title: | Using FEKO for Electromagnetic Analysis of Carbon-Fiber Composite Structures |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Simulation using FEKO Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 348 KB |
| Title: | Using Adaptive Cross Approximation for Efficient Calculation of Monostatic Scattering with Multiple Incident Angles |
| Abstract: | An adaptive cross approximation (ACA) based method is proposed for the fast analysis of the monostatic radar cross-section (RCS). Using the low-rank property, several largest eigenvalues and corresponding eigenvectors of the multiple right hand sides can be computed and saved efficiently by the ACA algorithm. The iterative solution of linear equations is required at these principle eigenvectors. Compared with solving linear equations at each angle repeatedly, the proposed method is able to greatly reduce the computation time. In order to efficiently solve the linear equations, the flexible general minimal residual (FGMRES) iterative solver is applied to compute the coefficients of Rao-Wilton-Glisson (RWG) basis functions. Numerical results demonstrate that the proposed method is efficient for monostatic RCS calculation with high accuracy. |
| Author(s): | Z. Liu, R. Chen, J. Chen, Z. Fan |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 4 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 2277 KB |
| Title: | Use of the Simultaneous Diagonalization Technique in the Ax=lBx Eigenproblem Applied to the Computation of the Characteristic Modes |
| Abstract: | Characteristic modes developed by Garbacz, Harrington and Mautz have long been used in the analysis of radiation and scattering from conducting bodies and apertures. For their computation, it is necessary to solve an eigensystem of the form Ax=lBx. If the matrices (A,B) are Hermitian and B is positive definite, the generalized eigenvalue problem can be accurately solved using the simultaneous diagonalization technique (SDT). Because of numerical approximations and rounding sometimes it may happen that the matrices properties deteriorate and the SDT procedure becomes inapplicable. In this work a new technique, developed recently by Higham and Cheng is proposed as a method to solve these deteriorate cases. It is applied to the computation of the characteristic modes for some scattering problems. Results are analyzed and discussed. |
| Author(s): | Giovanni Angiulli, Francesca Venneri, Giovanni Angiulli, Francesca Venneri |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 3 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 152 KB |
| Title: | Uncertainty Quantification Method of Crosstalk Involving Braided-Shielded Cable |
| Abstract: | In this paper, in view of the uncertainty of geometric parameters of braided-shielded cable and structural parameters of the shield in practical problems, polynomial chaos expansions (PCE) is used to explore the uncertainty quantification of a crosstalk calculation model of braided-shielded cable. First, the model based on multi-conductor transmission line theory is expanded by PCE. Second, the truncation degrees of polynomials and sample size of PCE are determined by the leave-one- out method, and the statistical characteristic parameters of crosstalk are obtained by combining coefficients of polynomials. Compared with the calculation results of the Monte Carlo method, the mean value, standard deviation and probability density function obtained by the two methods are basically consistent, but the PCE method has obvious advantages in calculation efficiency. Finally, the influence of input variable parameters in the crosstalk calculation model of braided-shielded cable are calculated by combining the PCE and the Sobol’s global sensitivity analysis method, which provides theoretical guidance for the electromagnetic compatibility design of electrical and electronic equipment using braided-shielded cable. |
| Author(s): | T. Tan, T. Jiang, H. Jiang, T. Wang, M. Ca |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 1 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 901 KB |
| Title: | Uncertainty Quantification and Global Sensitivity Analysis of Radiated Susceptibility in Multiconductor Transmission Lines using Adaptive Sparse Polynomial Chaos Expansions |
| Abstract: | This study analyzes the uncertainties of the radiated susceptibility in multiconductor transmission lines (MTLs), and introduces an adaptive sparse polynomial chaos expansion combining hyperbolic truncation scheme with orthogonal matching pursuit method (AS-PCE (OMP)). This method is used as the basis to realize the uncertainty quantification (UQ) of radiated susceptibility and global sensitivity analysis (GSA) of input variables to output variables. GSA considers the influencing factors of the incident field and transmission-line geometric parameters. The global sensitivity indices of each input variable are calculated for varying impedance loads. The accuracy and efficiency of the proposed method are verified compared with the results of the polynomial chaos expansion based least angle regression method and Monte Carlo methods. |
| Author(s): | Y. Zhu, Y. Wang, Q. Yu, D. Wu, Y. Zhang, T. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 10 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1113 KB |
| Title: | Uncertainty Analysis on Band-Stop Filter Using Data-Driven Arbitrary Polynomial Chaos |
| File Type: | Conference Paper |
| Issue: | Volume: S17 Uncertainty Quantification in CEM Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 273 KB |
| Title: | Uncertainty Analysis of the EMC Simulation Based on the Non-Intrusive Galerkin Method |
| Abstract: | Recently, as a high-efficient uncertainty analysis method, the Stochastic Galerkin Method has been widely applied in EMC simulations. In this method, the original solver must be changed during uncertainty analysis. Thus, the realization of the Stochastic Galerkin Method may become impossible in some cases. In this paper, a novel method named Non-Intrusive Galerkin method is proposed in order to sove this problem. The performance of the proposed method can be clearly shown by calculating a published example. |
| Author(s): | J. Bai, G. Zhang, L. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 8 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1424 KB |
| Title: | Uncertainty Analysis of Reflection Coefficient for a Coating with Random Flaws Using Adaptive Mesh and DGTD Method |
| Abstract: | An imperfect coating shall cause uncertainties in the analysis of electromagnetic properties. To quantify the influence of irregularity, complexity, and uncertainty of the coatings for electronic devices, an adaptive mesh algorithm combined with the discontinuous Galerkin time domain (AM-DGTD) method is developed. The uncertain variations are incorporated into the proposed algorithm by an appropriate parameterization. The standard statistical analysis is performed to calculate the appropriate moments, i.e., mean and variance. The developed method is validated by modeling a dielectric coating with uncertain flaws in an adaptive mesh grid. The computed quantities of interest from numerical estimations are compared with the analytical values, these results agree with the physical explanation, and are in good agreement with the exact values, as demonstrated by numerical experiments. |
| Author(s): | H. Li, I. Hussain, Y. Wang, Q. Cao |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 5 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2878 KB |
| Title: | Uncertainty Analysis in EMC Simulation Based on Improved Method of Moments |
| Abstract: | Recently, many uncertainty analysis methods have been taken into consideration in electromagnetic compatibility (EMC) simulation. As a traditional method, the Method of Moments (MoM) owns many advantages compared with other methods, especially in calculating the high dimension problems. However, its main disadvantage is the poor accuracy. In this paper, the Richardson extrapolation has been used to improve the MoM in order to promote the accuracy. By using feature selective validation (FSV), the effectiveness of the improvement can be obviously shown compared with the standard results calculated by the Monte Carlo Method (MC). |
| Author(s): | J. Bai, G. Zhang, L. Wang, T. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 1 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 321 KB |
| Title: | Ultra-wideband Miniaturized Electromagnetic Bandgap Structures Embedded in Printed Circuit Boards: Theory, Modeling and Experimental Validation |
| File Type: | Conference Paper |
| Issue: | Volume: Design and Analysis of Advanced Circuit Architectures Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 813 KB |
| Title: | Ultra-Wide Bandwidth Enhancement of Single-Layer Single-Feed Patch Antenna Using the Theory of Characteristic Modes |
| Abstract: | The Theory of Characteristic Modes (TCM) is proposed as a systematic approach to antenna design to achieve the goal of finding the antenna structure with optimum broadband behavior. This theory provides a physical insight to the radiating nature of microstrip patch antennas and reduces the design optimization time. In this work, the resonant behavior of the highly radiating structure of the single U-slot rectangular patch on a single-layer ?r = 4.4 substrate is analyzed using TCM. Modal analysis of this single-layer structure with different single feed excitations concludes that VSWR ? 2 impedance bandwidth in the order of 96% can be achieved with a single T-probe feed. Experimental results, included here, show VSWR ? 2 impedance bandwidth in the order of 71%. |
| Author(s): | M. M. Elsewe, D. Chatterjee |
| File Type: | Express Journal Paper |
| Issue: | Volume: 1 Number: 9 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1411 KB |
| Title: | Ultra-Wide Bandwidth Enhancement of Single-Layer Single-Feed Patch Antenna Using the Theory of Characteristic Modes |
| Abstract: | The Theory of Characteristic Modes (TCM) is proposed as a systematic approach to antenna design to achieve the goal of finding the antenna structure with optimum broadband behavior. This theory provides a physical insight to the radiating nature of microstrip patch antennas and reduces the design optimization time. In this work, the resonant behavior of the highly radiating structure of the single U-slot rectangular patch on a single-layer epsilon r = 4.4 substrate is analyzed using TCM. Modal analysis of this single-layer structure with different single feed excitations concludes that VSWR less than or equal to 2 impedance bandwidth in the order of 96% can be achieved with a single T-probe feed. Experimental results, included here, show VSWR less than or equal to 2 impedance bandwidth in the order of 71%. |
| Author(s): | M. M. Elsewe, D. Chatterjee |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 3 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1705 KB |
| Title: | Ultra-Wide Bandwidth Enhancement of Single-Layer Single-Feed Patch Antenna Using the Theory of Characteristic Modes |
| Abstract: | The Theory of Characteristic Modes (TCM) is proposed as a systematic approach to antenna design to achieve the goal of finding the antenna structure with optimum broadband behavior. This theory provides a physical insight to the radiating nature of microstrip patch antennas and reduces the design optimization time. In this work, the resonant behavior of the highly radiating structure of the single U-slot rectangular patch on a single-layer epsilon r = 4.4 substrate is analyzed using TCM. Modal analysis of this single-layer structure with different single feed excitations concludes that VSWR less than or equal to 2 impedance bandwidth in the order of 96% can be achieved with a single T-probe feed. Experimental results, included here, show VSWR less than or equal to 2 impedance bandwidth in the order of 71%. |
| Author(s): | M. M. Elsewe, D. Chatterjee |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 3 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1705 KB |
| Title: | Ultra-Compact Polarization Splitter Based on Silica Liquid Crystal Photonic Crystal Fiber Coupler |
| Abstract: | An ultra-compact polarization splitter based on dual core nematic liquid crystal silica photonic crystal fiber (NLC-PCF) is proposed and analyzed. The refractive index difference between the NLC and silica material guaranties the index guiding through the reported splitter. The dual core NLC-PCF has strong polarization dependence due to the birefringence between the two polarized modes. The coupling characteristics of the proposed design are studied thoroughly using full vectorial fine difference method (FV-FDM) and the propagation analysis is performed by full vectorial finite difference beam propagation method (FVFD-BPM). The numerical results reveal that the reported splitter has short device length of 482 µm with low crosstalk better than -20 dB with wide bandwidths of 31.5 nm and 19 nm for the quasi TE and quasi TM modes, respectively. The compact coupling lengths as well as the low crosstalks over reasonable bandwidths are the main advantages of the reported dual core NLC-PCF. |
| Author(s): | R. A. Hussein, M. F. O. Hameed, S. S. Obayya |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 594 KB |
| Title: | Ultra Wideband Antenna Analysis |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Electromagnetic Modeling by WIPL-D software II Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 348 KB |
| Title: | Ultra Low profile, Unbalanced Fed Inverted F Antenna on Finite Conducting Plane |
| File Type: | Conference Paper |
| Issue: | Volume: EM Applications using WIPL-D Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 545 KB |
| Title: | Ultra Low Profile Inverted L Antenna on Parallel Wires |
| File Type: | Conference Paper |
| Issue: | Volume: EM Simulations Using WIPL-D Characterization Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 126 KB |
| Title: | UHF-HF RFID Integrated Transponder for Moving Vehicle Identification |
| Abstract: | This paper presents a passive HF-UHF RFID integrated transponder for the identification of a moving vehicle. It consists of a single ISO 7810 ID-1 Card where both a UHF meander dipole antenna and an ISO 15693 commercial tag are arranged. The UHF antenna is designed by using a parametric analysis of the optimal shape of the meanders to obtain a proper conjugate matching between the antenna and the RFID microchip. A single-lane identification scenario is presented and simulated. The effects of the electromagnetic reflection and diffraction on the reading range as well as on the identification operations of a tagged vehicle are also investigated. Numerical simulations and experimental results on a prototype of the conduced transponder confirm the possibility of using this technology for the identification of a moving vehicle approaching a road-toll system with a relatively slow speed. |
| Author(s): | A. Toccafondi, C. D. Giovampaola, P. Braconi, A. Cucini |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 6 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 11189 KB |
| Title: | UHF Flared Notch Antenna Design for Linear Arrays |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Electromagnetic Modeling by WIPL-D software II Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 857 KB |
| Title: | Two-dimensional Full-wave Scattering at One Million Wavelength Objects |
| File Type: | Conference Paper |
| Issue: | Volume: Challenges in Scattering, Radiation and Multi-domain Modeling Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 672 KB |
| Title: | Two Element UWB-MIMO Antenna with Modified Ground Stub Structure |
| File Type: | Conference Paper |
| Issue: | Volume: S12 Advanced Optimization of Electromagnetic Structures - I Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 431 KB |
| Title: | Two Element Phased Array Dipole Antenna on Finite EBG Ground Plane |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Electromagnetic Modeling by WIPL-D Software Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 171 KB |
| Title: | Two Element Phased Array Dipole Antenna |
| Abstract: | Two element array of dipole antennas with 90 degree phase difference feed is proposed for directional antenna applications. In the numerical analysis, the electromagnetic simulator WIPL-D based on the method of moment is used. At first, the distance between the two elements is fixed to be a quarter wavelengths at the design frequency of 2.45 GHz. The front-to-back ratio is calculated. Then, by adjusting the length of the two elements and the distance between the two elements, a front-to-back ratio of 15.3 dB is obtained. The relation between the front-to-back ratio of this antenna and the feed point currents is discussed. The measured input impedance with 90 degree hybrid |
| Author(s): | Mitsuo Taguchi, Kotaro Era, Kazumasa Tanaka, Mitsuo Taguchi, Kotaro Era, Kazumasa Tanaka |
| File Type: | Journal Paper |
| Issue: | Volume: 22 Number: 1 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 272 KB |
| Title: | Two Element Phased Array Dipole Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Electromagnetic Modeling by WIPL-D Software Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 237 KB |
| Title: | Two Dimensional Frequency-Angle Domain Adaptive Combined Interpolation Method for Electromagnetic Scattering Analysis of Precipitation Particles |
| Abstract: | A combined 2-D interpolation method is proposed for the efficient electromagnetic scattering analysis of precipitation particles over a broad frequency and angular band. This method combines the cubic spline interpolation method and the Steor-Bulirsch model. The cubic spline interpolation method is applied to model the induced current over wide angular band. The Steor-Bulirsch model is applied to accelerate calculation over wide frequency band. In order to efficiently compute electromagnetic scattering, sparsematrix/ canonical grid method (SM/CG) is applied to accelerate the matrix vector multiplication in EFIE. Therefore, the calculation time of frequency and angular sweeps become shorter. Numerical results demonstrate that this combined method is efficient for wide-band scattering calculation of precipitation particles with high accuracy. |
| Author(s): | J. Chen, J. Lin, Z. Liu, N. Li, P. Ping, X. Ping |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 3 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1720 KB |
| Title: | Tunable Metasurfaces for Filtering the Electromagnetic Waves Under Different Excitations |
| Abstract: | In this study a tunable metasurface has been presented and evaluated for different excitation types. Tunability has been achieved by changing the substrate and geometrical properties. In order to obtain uniqueness, a parameter retrieval for the effective permittivity and permeability is performed using a version of the Nicholson-Ross-Weir (NRW) algorithm that is improved by implementing the Kramers-Kronig relationship. The results regarding the parametric and retrieval analysis are presented. |
| Author(s): | S. Can, E. Karakaya, F. Bagci, A. E. Yilmaz, B. Akaoglu |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 9 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2452 KB |
| Title: | Tucker-FMM-FFT-Accelerated SIE Solver for Large-Scale Electromagnetic Analysis |
| File Type: | Conference Paper |
| Issue: | Volume: S20 The Application of Tensor and Matrix Decompositions to the Electromagnetic Analysis Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 376 KB |
| Title: | Truncation Error Analysis of a Pre-Asymptotic Higher-Order Finite Difference Scheme for Maxwell's Equations |
| Abstract: | Pre-asymptotic higher-order methods are useful to the mitigation of numerical dispersion error in large-scale Finite-Difference Time-Domain (FDTD) simulations. Its truncation error is shown in this study to be 2 2 O O () () :: t s in general. In the limiting case where the CourantFriedrichs-Levy number approaches to zero, it becomes 2 4 O O () () :: t s . |
| Author(s): | Y. Shao, S. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 2 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 164 KB |
| Title: | Transmission plane models for parallel-plane power distribution system and signal integrity analysis |
| File Type: | Conference Paper |
| Issue: | Volume: Applied CEM for EMC Applications Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 120 KB |
| Title: | Transient Response of a Thin Wire above a Real Ground using a Simplified Reflection Coefficient Approach |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced EMC Modeling Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 221 KB |
| Title: | Transient Electro-thermal Analysis of the Bipolar Transistor |
| File Type: | Conference Paper |
| Issue: | Volume: S32 Electromagnetic Analysis on Circuits, Antennas, and Systems - I Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 245 KB |
| Title: | Transient Electro-Thermal Analysis of On-Chip Interconnects in the Presence of ESD Pulses Using DGTD Method |
| File Type: | Conference Paper |
| Issue: | Volume: 10-TE-1 Electromagnetic Environment Effects and Protection II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 295 KB |
| Title: | Transient Electro-Thermal Analysis of a Common Source Amplifier Circuit with a Physics-based MOSFET Model |
| Abstract: | An algorithm that combines a common source amplifier with the physics-based metal-oxidesemiconductor field effect transistor (MOSFET) model is proposed. By solving the coupled drift-diffusion model equations with spectral element time-domain (SETD) method, the distribution of electron quasi-Fermi potential, hole quasi-Fermi potential and the potential inside the MOSFET is obtained. The corresponding current densities and electric intensities distributed in the device can be used to couple the heat conduction equation. Furthermore, the Kirchhoff laws should be satisfied when the MOSFET device is inserted in the circuit. The Newton-Raphson method is used to solve the nonlinear circuit equations due to the existence of semiconductor devices. The transient electro-thermal characteristics of a common source amplifier circuit have been analyzed, and the numerical results demonstrate the validity of the proposed method. |
| Author(s): | T. Pan, D. Ding, H. Li, X. Cheng |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 7 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1348 KB |
| Title: | Transient Current Distribution and Force Analysis of Three Phase Enclosure Type GIB Based on Field-Circuit Coupling FEM Method |
| Abstract: | On the purpose of optimal design and online monitoring of three phase enclosure gas insulated bus (GIB), a 3-D circuit-field coupling FEM model has been developed. The current constriction effects in plug-in connectors are simulated by modeling contact bridges between contact surfaces and the influence of conductor gravity on contact resistance has been taken into account. The distributions of current which is constrained by external circuit are obtained from fieldcircuit coupling calculation and electromagnetic force, which is derived from electromagnetic field calculation, is used as load inputs in mechanical field analysis. The validity of calculation model is demonstrated by comparing with vibration experiments. The dynamic current distribution and electromagnetic force behaviors of three phase enclosure GIB under steady state and different short circuit conditions have been analyzed using the calculation model. Analysis results show that the uneven heating of contact fingers due to current distributions under steady state and contact fingers with smaller contact forces are seriously ablated by large short currents under short circuit conditions, and are the main contact degradation mechanism of plug-in connector. Conductor electromagnetic forces under single phase short circuit condition are larger than those of two phase and three phase short circuit conditions and the electromagnetic force peak moments under different fault conditions are not the same. |
| Author(s): | X. Guan, B. Kang, N. Shu, Q. Yan, Z. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 11 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1194 KB |
| Title: | Transient Analysis of Thin-Wire Antennas over Debye Media |
| Abstract: | This paper presents a numerical procedure to calculate the time-domain response of thin-wire antennas over Debye media. The method is based in an expansion of the electricfield integral-equation in the time-domain (EFIETD), which accounts for the Debye media by using a reflection-coefficient approach. Resulting extended integral equation is subsequently solved by the method of moments. Numerical examples including Debye soils show not only the accuracy of the method but also a higher computational efficiency in comparison with other hybrid numerical techniques. |
| Author(s): | M. F. Pantoja, A. R. Bretones, S. G. García, X. L. Travassos, R. G. Martín |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 3 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 1010 KB |
| Title: | Transient Analysis of Dispersion Medium with Conducting Strips buried in Different Depth |
| File Type: | Conference Paper |
| Issue: | Volume: S46 Time-Domain Techniques for Designing Electromagnetic and Optical Devices - II Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 208 KB |
| Title: | Transient Analyses of Grounding Electrodes Considering Ionization and Dispersion Aspects of Soils Simultaneously: An Improved Multiconductor Transmission Line Model (Improved MTL) |
| Abstract: | This paper proposes an approximate model in the frequency domain for transient analysis of grounding electrodes buried in ionized and dispersive soils. The proposed method, called multi-conductor transmission line model (MTL), can easily treat the frequency dependence of electrical parameters of soil. It can also incorporate soil ionization by gradually changing the respective electrode radius. Extensive simulation results are presented to confirm the accuracy of the MTL. |
| Author(s): | S. S. Sajjadi, V. Aghajani, S. R. Ostadzadeh |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 5 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1223 KB |
| Title: | Transient Adjoint Sensitivities for Problems with Multiple Discontinuities exhibiting Space Dependent Properties |
| File Type: | Conference Paper |
| Issue: | Volume: Efficient Solutions to Inverse Electromagnetic Problems Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 646 KB |
| Title: | Towards Wideband Hyperthermia Treatment System |
| Abstract: | This paper presents an overview of design and functionality of the essential modules proposed to build a wideband hyperthermia system. Description is provided of the waveform shaper, power amplifier and applicator array modules. Big data analysis is presented to accelerate energy localization depending on a time reversal technique. Simulation results are provided assuming a cylindrical head phantom characterized with wideband dispersive tissue properties, and the obtained field maps are shown in different planes to visualize energy localization process. Results reveal that wideband operation has the potential to enhance energy localization in deep tumor regions while eradicating hot spots, as compared to conventional narrowband systems. |
| Author(s): | N. Nizam-Uddin, W. Alkadri, W. A. Malik, I. Elshafiey, A. F. Sheta |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 9 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 2587 KB |
| Title: | Tolerance Analysis and Robust Design in Engineering Electromagnetics – An Interval Analysis Perspective Abstract |
| File Type: | Tutorial Abstract |
| Issue: | Volume: S56 Tolerance Analysis and Robust Design in Engineering EM Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 457 KB |
| Title: | TM scattering from nite rectangular grooves in a conducting plane using overlapping Tblock analysis |
| File Type: | Conference Paper |
| Issue: | Volume: Fast and Efficient CEM Methods Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 189 KB |
| Title: | Time-Domain Spectral Inversion Method for Characterization of Subsurface Layers in Ground-Penetrating-Radar (GPR) Applications |
| Abstract: | Ground-Penetrating-Radar (GPR) data analysis has been widely utilized in subsurface and geophysics applications. One of the applications turning into great importance is multilayer subsurface hydraulic parameter identification and soil water content estimations. The classic GPR techniques have shown limitations in detecting deeper soil layers and unsatisfactory accuracy in estimating the electrical properties of the layers. Spectral inversion methods have been recently identified and developed to be an effective tool to tackle these problems. In this work, the spectral inversion method is extended in time-domain and a comprehensive formulation of the algorithm along with an improved well-defined cost function is presented. The Time-Domain Spectral Inversion (TDSI) method is then applied to environmentally-relevant multilayer soil geometries and the corresponding estimated electrical properties are drawn. The results show the TDSI method considerably ameliorates the performance of the inversion in terms of simplicity, accuracy, and applicability. |
| Author(s): | Z. Motevalli, B. Zakeri |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2142 KB |
| Title: | Time-Domain Response of 3-D Structures Calculated Using WIPL-D |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Electromagnetic Modeling by WIPL-D Software Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 647 KB |
| Title: | Time Response Analysis of Cable over Anisotropic Half Space |
| File Type: | Conference Paper |
| Issue: | Volume: 9-P-2 Poster Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 272 KB |
| Title: | Time of Flight Extraction of Dispersive Lamb Wave by Ridge Analysis |
| File Type: | Conference Paper |
| Issue: | Volume: 5-P-1 Poster Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 263 KB |
| Title: | Time Domain Parabolic Equation Method for Scattering Analysis of Electrically Large Coated Objects by using Impedance Boundary Condition |
| Abstract: | The time domain parabolic equation method (TDPE) is an efficient tool for analyzing electromagnetic (EM) scattering by electrically large objects. It reduces the cost of computational resources by dividing threedimensional solution space into multiple twodimensional transverse planes for calculating scattered fields one by one. For thin coated perfectly electrically conducting (PEC) objects, the efficiency of TDPE method will decrease if dielectric is considered to be meshed. As an approximate method, Leontovich impedance boundary condition (IBC) handles this problem by modeling a surface impedance on the outer surface of coating dielectric, instead of solving Maxwell's equations in the dielectric domain. Thus in this paper, TDPE method based on Leontovich IBC is proposed to analyze broadband scattering problems of large-scale coated PEC objects. Numerical results have validated the accuracy and efficiency of the proposed method. |
| Author(s): | L. Guan, S. Tao |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 12 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1612 KB |
| Title: | Time Domain Analysis of Ultra-Wide Band Signals from Buried Objects Under Flat and Slightly Rough Surfaces |
| Abstract: | The analysis of transient scattering for TMz (horizontally) polarization from a cylindrical perfectly conducting (PEC) object buried in a lossy medium is considered. Flat and slightly surface cases are considered for the dielectric halfspace. Our previous work using a decomposition method solution in frequency domain of TMz polarization is utilized to solve this scattering problem. Then, an inverse Fourier transform is used to get the time domain signals. Timing analysis is done by calculating the travelling time of reflected signals in the possible paths. Then, multiple reflections are identified using these travelling times. Finally, the results from the flat and slightly rough surface profiles are used to compare the effects of multipath propagation. |
| Author(s): | S. MakalYucedag, A. Kizilay |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 8 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 519 KB |
| Title: | Time Domain Analysis of GaAS MESFET Transistors Excited by an Incident Electromagnetic Field |
| Abstract: | A numerical method for the fully distributed modeling of Field Effect Transistor (FET) excited by an incident electromagnetic field using a Finite-Difference Time-Domain (FDTD) method is described. The transistor is modeled using the fully distributed model which consists of a configuration of the conventional equivalent circuit of the transistor and three coupled lines as each distributed element. The distributed source terms represent the coupling with an electromagnetic field in the equation which can be used in the Electromagnetic Interference (EMI) analysis. As a numerical example, the method is applied to a GaAs MESFET and the time domain results are presented. |
| Author(s): | L. Mirzavand, A. Abdipour, R. Mirzavand |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 10 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 637 KB |
| Title: | Time Domain Analysis of a Microstrip Line Excited Compact Rectangular Dielectric Resonator Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: FDTD and Applications Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 76 KB |
| Title: | Time and Frequency Evolution of Precursor Fields in Dispersive Media using FDTD and Joint Time-Frequency Analysis |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Analysis of Wave Phenomena Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 225 KB |
| Title: | Three-Dimensional Electromechanical Coupled Analysis for Capacitive RF MEMS Switches |
| File Type: | Conference Paper |
| Issue: | Volume: Novel Modeling Techniques and RF MEMS Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 831 KB |
| Title: | Three-Dimension Finite Element Analysis of a Helical Motion Induction Motor |
| Abstract: | The paper presents a three-dimensional finite element analysis applicable to all forms of sheet rotor, cylindrical, linear induction motor, as well as, helical motion induction motor. The analysis accounts for longitudinal and transverse end effects, skin depth and finite sheet thickness; furthermore, there is practically no restriction on the shape of magnetic circuit that can be considered. It yields detailed space profile of the state variables. The winding arrangement may include multi-polar system circumferentially and axially. The excitation produced by such winding is a helically traveling wave. The formulation results in a set of linear equations which are solved by point relaxation method. The solution algorithm employs power mismatch in the machine to indicate accuracy. The theory is supported by experimental results. |
| Author(s): | J. H. Alwash, L. J. Qaseer |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 8 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 352 KB |
| Title: | THREE METHODS FOR EVALUATION OF FREQUENCY-DEPENDENT RESISTANCES AND INDUCTANCES OF MULTICONDUCTOR TRANSMISSION LINES |
| Abstract: | Three methods for the analysis of frequency-dependent resistances and inductances of multiconductor transmission lines are outlined and compared. The first method comes from power-engineering applications, and it is based on a numerical solution of an integral equation for the distribution of the conductor volume currents. The second method is based on the perturbation technique. The third method comes from high-frequency applications, and it is based on the principle of equivalent surface electric and magnetic currents. [Vol. 9, No. 2 (1994), Special Issue on The Numerical Computation of Low Frequency Electromagnetic Fields, pp 43-56] |
| Author(s): | Antonije R. Djordjevic, Tapan K. Sarkar, Antonije R. Djordjevic, Tapan K. Sarkar |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 2 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 797 KB |
| Title: | Three Dimensional Finite Element Analysis for the Study of Voltage Drop Behavior in Zinc Air Batteries under Load Conditions |
| File Type: | Conference Paper |
| Issue: | Volume: S20 Advanced Computational Techniques in Electromagnetics Number: Year: 2015 |
| Download Link: | Login To Download (For Members) File Size: 289 KB |
| Title: | Thin Wire Representation of the Vertical Conductor in Surge Simulation |
| Abstract: | Abstract— Simulation of very fast surge phenomena in a three-dimensional (3-D) structure requires a method based on Maxwell’s equations, such as the FDTD (finite difference time domain) method or the MoM (method of moments), because circuit-equation-based methods cannot handle the phenomena. This paper describes a method of thin wire representation of the vertical conductor system for the FDTD method which is suitable for the 3-D surge simulation. The thin wire representation is indispensable to simulate electromagnetic surges on wires or steel frames of which the radius is smaller than a discretized space step used in the FDTD simulation. A general surge analysis program named VSTL (Virtual Surge Test Lab.) based on the Maxwell equations formulated by the FDTD method is used to simulate the surge phenomena of a vertical conductor, including the effects of ground plane and without ground plane. By use of the Maxwell equations, VSTL is inherently able to take into account the three-dimensional geometrical features of a simulated structure unlike EMTP-type circuit-based transient programs. Comparisons between calculated results by the FDTD method, theoretical results and computed results by the NEC-2 (Numerical Electromagnetic Code) based on the MoM are presented to show the accuracy of the thin wire representation. |
| Author(s): | Md. Osman Goni, Eiji Kaneko, Hideomi Takahashi, Md. Osman Goni, Eiji Kaneko, Hideomi Takahashi |
| File Type: | Journal Paper |
| Issue: | Volume: 19 Number: 1 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 322 KB |
| Title: | Thermal-Aware DC IR-Drop Co-Analysis of 3-D ICs using Non-Conformal Domain Decomposition Methods |
| File Type: | Conference Paper |
| Issue: | Volume: Multi-Physics Modeling and Simulations Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 241 KB |
| Title: | Thermal Simulation of a Conductive Fabric Sheet Subjected to a Lightning-like Current |
| File Type: | Conference Paper |
| Issue: | Volume: S14 Numerical Methods for Diverse Applications Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 432 KB |
| Title: | Thermal Simulation of a Conductive Fabric Sheet Subjected to a Lightning-like Current |
| Abstract: | A sample of electroconductive fabric subjected to a lightning-like current impulse is analyzed in this contribution. A multiphysics simulation is used to calculate the temperature distribution produced by a lightning-like current flowing through the material sample. A decoupled, electromagnetic (EM) and thermal, simulation was conducted for the analysis and is explained in the paper. The scaling factor calculation to represent the energy presented during current impulse tests is also detailed. Numerical results present patterns that agree with experimental tests reported in the literature and represent an additional tool for the phenomena insight. |
| Author(s): | J. J. Pantoja, C. Rivera, J. Cristancho, J. Rodriguez, F. Roman |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1369 KB |
| Title: | Thermal Effects of 5G Frequency EM Waves on Ocular Tissue |
| Abstract: | This research article aims to investigate the thermal effects on human eye due to exposure of EM (electromagnetic) field at 5G frequencies. A secondary purpose of the article is to show that SPICE, one of the most commonly used tools in circuit analysis, can be used to solve complex EM and bioheat transfer problems. Both electric field and temperature distributions in human eye are simulated with transmission line modelling (TLM) method. Also, finite element method (FEM) calculations are carried out for comparison. Temperature distributions are calculated for 30 minutes of EM radiation exposure. As a subject of the simulation, a human is chosen that the power density of incoming field at the human eye is assumed as the maximum of the ICNIRP general public exposure limits. A good consistency between TLM and FEM based simulations is found. A new transmission line model based on Debye parametric model is generated for simulation of EM field distribution in the tissues. With this generated transmission line, the results for the frequencies of interest can be obtained via single simulation. Also, a new transmission line model is developed for the temperature distribution simulation in which the effects of noncompressible fluid flow such as non-unidirectional blood flow in tissues and flow in aqueous humor are taken into consideration. |
| Author(s): | B. Aricioglu, A. Ferikoglu |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 4 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1834 KB |
| Title: | Thermal Analysis and Phase Transformation of Ti6Al4V Alloy Fabricated by Direct Metal Laser Sintering |
| File Type: | Conference Paper |
| Issue: | Volume: S36 Large Scale Computing - I Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 373 KB |
| Title: | The Tilted-Ellipse Representation of Standing-Wave Patterns. |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in CEM Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 1221 KB |
| Title: | The Theoretical Analysis on Electromagnetic Signal Transmission for Down-hole to Surface |
| File Type: | Conference Paper |
| Issue: | Volume: 2-P2-A Electromagnetic Theory Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 276 KB |
| Title: | The Synthesis of Frequency Selective Surfaces for Infrared Filters |
| File Type: | Conference Paper |
| Issue: | Volume: Nanoscale Frequency Selective Surfaces Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 429 KB |
| Title: | The Spatial Distributions of Radiation Emitted from a Sinusoidal Current Filament and a Dipole Antenna |
| Abstract: | While the analytical and numerical tools for determining the basic properties of a variety of antenna types have been long-established, there remains some continuing curiosity about how electromagnetic radiation is launched by such a simple antenna as a dipole. The following article discusses this problem in both the frequency domain and time domain. The sinusoidal current filament (SCF) is investigated first as a prototype of a wire dipole. The length-wise distribution of radiated power for the SCF is obtained from the distributed radiation resistance of Schelkunoff and Feldman, the induced electromotive force (IEMF) method, and the far-field analysis of radiation sources (FARS) developed by the author. The FARS approach is next used to analyze a frequency-domain numerical model of a dipole antenna, producing results similar to those for the SCF for a dipole of near-zero radius. Differentiating the decaying onsurface Poynting vector (PV) produces results comparable to those from FARS to explicitly demonstrate the power loss caused by radiation of the propagating current and charge. The lobed distributed radiated power is shown to be closely correlated with the square of the dipole current, confirming the cause of the radiation to be due to a partially reflected charge as the current and charge form standing waves on the dipole. Application of a time-domain version of FARS yields a smoothed length-wise distribution of radiated energy as opposed to the lobed variation of the frequency domain. |
| Author(s): | E. K. Miller |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 4 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 1517 KB |
| Title: | The Sinusoidal Ground Electrode: Theory and Case Study Results |
| Abstract: | This paper presents the analytical analysis of the sinusoidal ground electrode commonly used in Portugal by the Portuguese Electric Company. This electrode is easy to install, particularly for two layer soils with rocky bottom layer, and costs much less than it does a strip conductor. Both the theoretical results as well as measurements in the field have shown that the empirical model used by the company leads to large errors. Here the authors propose a new procedure to calculate the grounding resistance for this type of electrode using the average resistance between the wire and strip electrodes, which the calculation is well-established. To avoid heavy computation, the authors also propose the use of simple formulas in order to easily compute the strip resistance. The theoretical results and field measurements are compared and show the validity of the procedure being proposed here. |
| Author(s): | A. M. R. Martins, S. J. P. S. Mariano, M. R. A. Calado, J. A. M. Felippe de Souza |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 3 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 3236 KB |
| Title: | The Role of High Fidelity Geometry Import in RF Modeling |
| File Type: | Conference Paper |
| Issue: | Volume: FEKO Modeling and Analysis IV Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 239 KB |
| Title: | The Reduction of Force Component Produced by Short Sides by Analyzing the Corner of Coil in Planar Motor with Halbach Magnet Array |
| Abstract: | The planar motor with moving-magnet is purely levitated by the stator coils. The forces produced by coils are calculated with the analytical model of magnet array and coil surface model for applying to the real time control. Take the coil and the Halbach magnet array which is at 45 degree with the long side of coil for analysis. The force component produced by short sides can be eliminated for conveniently controlling when the length of coil takes certain dimension. In practice, the force component produced by short sides is small but not zero. There are two reasons, one is the higher harmonics and the other is the corner segments of coil. The force integral expressions of coil corner segments are given by the Lorenz force law. Then the forces numerically calculated with harmonic model and coil full model are verified by comparing with the magnetic surface charge model and finite element model. In order to reduce the force component produced by short sides, the different corners of coil are analyzed. Comparing the forces of different corners of coil, the force component produced by short sides can be significantly reduced with slightly change of the other force components. |
| Author(s): | G. Liu, S. Hou, W. Xiao |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 1 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1421 KB |
| Title: | The Partial Element Equivalent Circuit Technique for EMI, EMC, and SI Analysis |
| File Type: | Newsletter Paper |
| Issue: | Volume: 21 Number: 1 Year: 2006 |
| Download Link: | Click here to download PDF File Size: 523 KB |
| Title: | The Parallel FETI-DPEM Eigensolver for Analysis of 3D Electromagnetic Cavities |
| File Type: | Conference Paper |
| Issue: | Volume: Parallelized Computing for Accelerated EM Applications Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 6319 KB |
| Title: | The Optimal Design of Real Time Control Precision of Planar Motor |
| Abstract: | In this paper, the Halbach permanent magnet array with 2 segments per pole is selected for analysis. The harmonics that the harmonic numbers for the lx and ly-direction in local coordinate system are equal to each other are set as a pair for transformation. Then the expressions of the magnetic flux density distribution of the Halbach array in global coordinate system are derived. The dimensions of the coil are parameterized. The force and torque exerted on the Halbach array by a coil are calculated by Lorentz force law. The first three harmonics are chosen for real time control by analyzing the ratio of each harmonic in the total harmonics. The harmonic model has good performance on torque by comparing with the models used before. As for the force, the errors can be significantly reduced by optimizing the parameterized dimensions of coil because of the cosine or sine form error figures. The optimized model has good precision on both force and torque. The same method can be applied on the Halbach permanent magnet array with different segments per pole. |
| Author(s): | G. Liu, Y. Wang, X. Xu, W. Ming, X. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 10 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 2376 KB |
| Title: | The Novel Adaptive Method for Interference Suppression |
| File Type: | Conference Paper |
| Issue: | Volume: S55 Devices and Applications Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 568 KB |
| Title: | The Influence of Thermal Deformation on the AMB-rotor System of HTR-PM Helium Circulator |
| Abstract: | Helium circulator is the core component of High Temperature Reactor-Pebblebed Modules (HTRPM), and its rotor is supported by active magnetic bearings (AMBs). The windings of the motor and AMBs will generate a great deal of heat due to Ohmic loss, which increases the temperature of the circulator. The high temperature will cause the thermal deformation of AMB-rotor system, leading to the clearance change between rotor and AMBs. The AMB stiffness and inductive transducer sensitivity will be affected by the changed clearance, which decrease the stability of the AMB-rotor system. In this paper, through theoretical analysis and finite element analysis (FEA), the influence of thermal deformation on the AMB stiffness and transducer measurement is studied. The simulation and experiment for the AMB-rotor system in the circulator is carried out to explore the performance of AMB controllers and the influences of thermal deformation on the unbalanced response of the AMB-rotor system is analyzed. The theoretical calculations in this paper has general applications in the controller improvement of AMBs under clearance change and provides a reference for mechanical structure design and controller design of AMBs. |
| Author(s): | J. Yu, G. Du, H. Wang, Z. Sun, L. Zhao |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 7 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1871 KB |
| Title: | The Influence of Non-uniform Flow Field Characteristics of Hypersonic Vehicle on Electromagnetic Wave Propagation |
| File Type: | Conference Paper |
| Issue: | Volume: 1-SP-2 Electromagnetic Characteristics of Complex Media Simulated by Time Domain Method I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 4330 KB |
| Title: | The Human Body Modelled by Canonical Geometric Shapes for the Analysis of Scattered E-fields |
| Abstract: | The objective of this paper is to propose a simplified model of a human body to be used in electromagnetic problems involving high frequency field scattering. Canonical geometric shapes, analytically described, represent the body. The accuracy of the model was tested comparing the field scattered by the simplified body representation with the one scattered by a more realistic phantom. At first, the influence of anatomical details of the body was analysed, comparing the electromagnetic field reflected by a realistic human head with the backscattering of spheres and of an ellipsoid. A second test concerns the human body, modelled by sphere, parallelepiped and cylinders. In this case, the possibility of reconstructing a wideband pulse scattered by the whole body with the superposition of pulses scattered by its separated parts was demonstrated. Both analyses were carried out in the frequency range 3- 5 GHz using a full wave numerical simulator. |
| Author(s): | G. Manfredi, V. Di Mattia, P. Russo, A. De Leo, G. Cerri |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 7 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1762 KB |
| Title: | The General Sidelobe Cancellation Based on Linear Minimum Variance At Subarray Level |
| File Type: | Conference Paper |
| Issue: | Volume: S61 Antenna Arrays Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 225 KB |
| Title: | The FDTD-based Time-Reversal Method for Diagnosis of Antenna Arrays |
| File Type: | Conference Paper |
| Issue: | Volume: 2-SE-3 Advances in Electromagnetic Theory and Simulation Techniques II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 237 KB |
| Title: | The Extension of the Nonstandard FDTD Method and Its Applications |
| File Type: | Conference Paper |
| Issue: | Volume: Non-Standard FDTD Methods Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 50 KB |
| Title: | The Effects of PCB Split Reference Planes on High Speed Signals: Analysis and Mitigation |
| File Type: | Conference Paper |
| Issue: | Volume: EMC Design Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 257 KB |
| Title: | The Effect of Fabrication Tolerances on a Suspended Plate Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: S19 Modeling with FEKO Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 624 KB |
| Title: | The Effect of Curvature on the Performance and Readability of Passive UHF RFID Tags |
| Abstract: | In this paper, the effect of curvature on the passive UHF RFID tag is studied. Maxwell’s equations are used to depict the typical curved passive tag and are used to study the theoretical limitations of a tag operating under curvatures at its normal axes. This theoretical framework is then used to analyze the typical tag for various curvatures. Here, the analysis is conducted to derive the effect of curvature on the optimal impedances for ASIC load matching, as well as gain. This analytical evaluation is also generalized to describe the shift in center frequency of the tag operation due to tag curvatures. The results derived from this theoretical study on commercially available passive UHF RFID tags are verified with experimental results. It is shown that the curvature of passive UHF RFID tags have a significant impact on the performance and readability at values of ?? > ?????, and reaches a breakdown on conformity at curvature values of ?? = 4?????. |
| Author(s): | D. D. Arumugam, D. W. Engels, M. H. Mickle |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 3 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 2769 KB |
| Title: | The Design of a Spherical Wire Frame Radar Target Using Mathematica for Structure and WIPL for Radar Cross Section |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling by WIPL-D Software Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 1009 KB |
| Title: | The Design and Analysis of a Static and Extremely Low-Frequency Magnetic Field Stimulation Platform for Cell Prolifation Inhibition |
| File Type: | Conference Paper |
| Issue: | Volume: 1-SP-3 Advances in Electromagnetic Theory and Simulation Techniques I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 286 KB |
| Title: | The Computational Electromagnetic Modelling of the CH-146 Griffon Helicopter Using FEKO |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Simulation using FEKO Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 361 KB |
| Title: | The Complementary Roles of Analysis, Synthesis, Numerics, and Experiment in Electromagnetics |
| Abstract: | |
| Author(s): | C. Baum, C. Baum |
| File Type: | Journal Paper |
| Issue: | Volume: 20 Number: 3 Year: 2005 |
| Download Link: | Click here to download PDF File Size: 236 KB |
| Title: | The Comparison of EMF Monitoring Campaigns in Vicinity of Power Distribution Facilities |
| Abstract: | Monitoring of electromagnetic field (EMF) near power distribution facilities, both in the low- and the high-frequency ranges, has become highly demanded in recent years. The reason lies in the accumulated concerns on public health, which is mostly caused by the evolution of electric power and communication infrastructure, in and around the power substations, as well as their closeness to residential areas. In this paper, the initial comparative analysis of the EMF monitoring results of three one-day campaigns, in 2015, 2018 and 2020, performed in the vicinity of the Serbian highpower distribution substation “Novi Sad 7”, is presented. The overall EMF levels in all campaigns comply with the reference levels prescribed by the Serbian legislation, including some new EMF sources which were detected in 2018 and 2020. Likewise, the used continuous monitoring has demonstrated suitability to systematically address EMF fluctuation on daily basis, as well as corresponding concerns on EMF exposure. |
| Author(s): | G. S. Nedic, N. M. Djuric, D. R. Kljajic |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 1 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 21425 KB |
| Title: | The Channel Characterization and Performance Evaluation of Mobile Communication Employing Stratospheric Platform |
| File Type: | Conference Paper |
| Issue: | Volume: Propagation Channel Characterization Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 210 KB |
| Title: | The Calculation and Analysis of Shielding Efficiency |
| File Type: | Conference Paper |
| Issue: | Volume: 3-P3-G EMC/EMI, Signal/Power Integrity Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 190 KB |
| Title: | THE APPLICATION OF THE FINITE ELEMENT METHOD IN DESIGN OF ELECTRIC MOTORS |
| Abstract: | The classical approach to design of electric motors is based on the concept of simplified magnetic circuit analysis. This approach fails in today's design situation due to utilization of new materials and new designs. Application of sophisticated numerical methods becomes inevitable. Some problems arising in the application of the finite element method in design of electric motors are discussed in this paper. Electric motors are always part of a system and their behaviour within the system, which is characterized by integral parameters (torques and reactances), should be known at the design stage. Computation of these parameters from a finite element magnetic field solution is described here. The computation of torque/angle characteristics from finite element field solution by application of two basic approaches: - global virtual work method and cubic spline interpolation technique, - Maxwell stress tensor integration, is described. The applicability of both approaches is illustrated by computation of the torque in a switched reluctance motor and the advantages of virtual work approach are emphasised. The main problem in application of the finite element method to computation of magnetic fields in electric motors is that the field sources (currents) and load angle are unknown. External environment (terminal voltage and mechanical load) are known, and the magnetic field solution is iterated until the external constraints are satisfied. To avoid finite element mesh rotation an iterative process was implemented in which only the fundamental harmonic of the lumped stator winding distribution is taken into consideration instead of the three-phase winding excitation. The direct and quadrature reactances are computed from the finite element magnetic field solution utilizing flux linkage and stored energy approaches. The procedure is illustrated by computation of the reactances of a permanent magnet synchronous electric motor. [Vol. 9, No. 2 (1994), Special Issue on The Numerical Computation of Low Frequency Electromagnetic Fields, pp 30-36] |
| Author(s): | Z. Haznadar, Z. Stih, S. Berberovic, G. Manenica, Z. Haznadar, Z. Stih, S. Berberovic, G. Manenica |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 2 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 544 KB |
| Title: | The Application of Design of Experiments to RF Systems |
| File Type: | Conference Paper |
| Issue: | Volume: S23 EM Modeling Using FEKO I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 238 KB |
| Title: | The Analysis of Two Dimensional High-Order Hierarchical Basis Function in DGTD Method |
| File Type: | Conference Paper |
| Issue: | Volume: 4-4-A Time Domain Computational Mehtods II Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 207 KB |
| Title: | The Analysis of the Resolution of Impulse Signal Circular Synthetic Aperture Radar Imaging |
| File Type: | Conference Paper |
| Issue: | Volume: 11-WA-4 Scattering Center Models and Their Applications Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 254 KB |
| Title: | The Analysis of the Additional Substance Influence on the Grounding Grid Parameters by FEM |
| File Type: | Conference Paper |
| Issue: | Volume: Low Frequency Electromagnetic Applications Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 0 KB |
| Title: | The Analysis of Multistep Cylindrical Structure on the Dielectric Surface for Wideband Radar Cross Section Reduction at Normal Incidence |
| File Type: | Conference Paper |
| Issue: | Volume: 1-3-E Electromagnetic Compatibility I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 193 KB |
| Title: | The Analysis of Arbitrary Dispersive Models by using AH FDTD Method |
| File Type: | Conference Paper |
| Issue: | Volume: 9-P-2 Poster Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 197 KB |
| Title: | The Analogy between Offset Configurations of Parabolic Reflectors and Reflectarrays |
| Abstract: | The analogous relationship between the design parameters of offset parabolic reflectors and offset reflectarrays is delineated. Each antenna is specified with four design parameters that best describe the system setup, and the mathematical relationship between the design parameters of these two antenna systems are determined. The presented study allows one to determine the analogous reflectarray system based on the design parameters of the offset reflector and vice versa. This makes it possible to simplify the configuration setup in offset reflectarrays using a coordinate system and a set of parameters that is very suitable for reflectarray design and analysis. |
| Author(s): | P. Nayeri, A. Z. Elsherbeni, F. Yang |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 11 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1688 KB |
| Title: | The Adaptive Interference Suppression Method Based on Householder At Subarray Level |
| File Type: | Conference Paper |
| Issue: | Volume: S55 Devices and Applications Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 412 KB |
| Title: | TF/SF Separation Characteristics in the 3D NS-FDTD Technique Using Rectangular Cells |
| File Type: | Conference Paper |
| Issue: | Volume: S03 Algorithms for Unique Applications I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 998 KB |
| Title: | Tesla Transformer and its Response with Square Wave and Sinusoidal Excitations |
| Abstract: | This paper analyses the output of Tesla transformer from input defined as square wave and sine wave and its transfer function obtained from its equivalent circuit. The transfer function presented is analyzed in terms of the time, and the output is obtained when applying an input defined as a step and a sine function. When using square wave, the high gain obtained is proved that is due to a sum of responses obtained through positive and negative step that forms the square wave. However, the gain obtained when the excitation is a sine wave is higher than square wave excitation. Thus, in this paper is shown that the Tesla transformer works with sinusoidal excitation too, and present higher gain than square wave excitation, both higher than expected in classical transformer theory (turns ratio). All analysis presented were based in simulating operation using MATLAB® comparing with experimental data. |
| Author(s): | E. M. M. Costa |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 9 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 681 KB |
| Title: | Temperature Effects Analysis on Microwave Rectifiers by Field-Circuit Hybrid Multiphysics Simulation |
| Abstract: | This work analyzes the temperature effects on microwave circuits by employing a novel field-circuit hybrid multiphysics simulation. Firstly, the multiphysics simulation is implemented by solving the coupled governing equations including Poisson equations, semiconductor transport equations, and thermodynamic equations; then, the multiphysics simulation is incorporated into circuit analysis; finally, the circuit simulation results are integrated into the finite-difference timedomain (FDTD) simulation by equivalent sources. In this manner, a field-circuit hybrid multiphysics simulation method is presented. Taking two different microwave rectifiers operating at S- and C-band as examples, temperature effects are analyzed by the proposed approach. Simulation results are in good agreement with measured values, demonstrating the accuracy and applicability of the proposed approach. The presented method more suitably reveals the temperature effects on the rectifier. |
| Author(s): | H. Zeng, Y. Chen, C. Zhou, Y. Tang, X. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 7 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 3509 KB |
| Title: | Technical Feature Article "Using Joint TimeFrequency Domain Analysis to Analyze Time Domain Simulations of Shielding Structures |
| Abstract: | |
| Author(s): | |
| File Type: | Newsletter Paper |
| Issue: | Volume: 18 Number: 1 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 1038 KB |
| Title: | Systematic CMA of the U-slot Patch with FEKO |
| File Type: | Conference Paper |
| Issue: | Volume: S03 EM Modeling using Feko/WinProp Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 468 KB |
| Title: | Systematic CMA of the U-slot Patch with FEKO |
| Abstract: | Since its introduction 25 years ago, the probe-fed Uslot patch antenna has remained popular. Recently, Characteristic Mode Analysis (CMA) revealed these devices are governed by Coupled Mode Theory (CMT). Although this principle is conceptually simple, achieving this understanding is only possible through a systematic analysis using CMA. This paper uses the Uslot patch to illustrate a general process for analyzing electrically small antennas using CMA with the software package FEKO. |
| Author(s): | J. J. Borchardt |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1615 KB |
| Title: | Systematic Analysis on the Optical Properties of Chiral Metamaterial Slab for Microwave Polarization Control |
| Abstract: | Theoretical and numerical of investigation of the chiral slab exhibiting polarization rotation is presented in detail. The effects of the chirality, thickness of medium, dielectric constant, and incident angle are analyzed in order to display the characteristic features of the chiral slab both for TE and TM incident waves. The chiral slab then is realized by using a full wave EM simulation software in order to validate the numerical results in which the numerical and simulation results are in good agreement with each other. Different than the other studies existing in literature, the proposed model shows optimum results for wide frequency band by using small chirality which is sufficient for polarization rotation. From the results, it is observed that the proposed system and its realization can be effectively used as a polarization converter and EM filters at some frequencies. |
| Author(s): | I. Comez, M. Karaaslan, F. Dincer, F. Karadag, C. Sabah |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 5 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1066 KB |
| Title: | System-Level EMC Antenna Coupling Analysis for Large, Complex Structure Topologies Using a Multi- Fidelity Modeling and Simulation Approach |
| File Type: | Conference Paper |
| Issue: | Volume: Computer Modeling and Simulation Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 134 KB |
| Title: | Symbolic Regression for Derivation of an Accurate Analytical Formulation Using “Big Data”: An Application Example |
| Abstract: | With emerging of the Big Data era, sample datasets are becoming increasingly large. One of the recently proposed algorithms for Big Data applications is Symbolic Regression (SR). SR is a type of regression analysis that performs a search within mathematical expression domain to generate an analytical expression that fits large size dataset. SR is capable of finding intrinsic relationships within the dataset to obtain an accurate model. Herein, for the first time in literature, SR is applied to derivate a full-wave simulation based analytical expression for the characteristic impedance Z0 of microstrip lines using Big Data obtained from an 3DEM simulator, in terms of only its real parameters which are substrate dielectric constant ?, height h and strip width w within 1-10 GHz band. The obtained expression is compared with the targeted simulation data together with the other analytical counterpart expressions of Z0 for different types of error function. It can be concluded that SR is a suitable algorithm for obtaining accurate analytical expressions where the size of the available data is large and the interrelations within the data are highly complex, to be used in Electromagnetic analysis and designs. |
| Author(s): | P. Mahouti, F. Günes, M. A. Belen, S. Demirel |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 5 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 2007 KB |
| Title: | Surface-wave Transmission Analysis on Dielectric Coated Conducting Wires |
| File Type: | Conference Paper |
| Issue: | Volume: 5-P-1 Poster Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 200 KB |
| Title: | Surface Plasmon Photonic Crystal Fiber Biosensor for Glucose Monitoring |
| File Type: | Conference Paper |
| Issue: | Volume: S52 Novel Photonic Material and Devices II Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 273 KB |
| Title: | Surface Based Differential Forms |
| File Type: | Conference Paper |
| Issue: | Volume: Hybrid CEM Techniques Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 188 KB |
| Title: | Subwavelength Metallic Grating Simulation Using FDTD |
| File Type: | Conference Paper |
| Issue: | Volume: Microwave, Optical Devices, and Propagation Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 293 KB |
| Title: | Subwavelength Focusing In The Infrared Range Using A Meta Surface |
| File Type: | Conference Paper |
| Issue: | Volume: S05 Novel Photonic Material and Devices I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 399 KB |
| Title: | Sub-harmonic-based Cost-effective Brushless Wound Rotor Synchronous Machine Topology |
| Abstract: | This paper proposes a sub-harmonic-based brushless wound rotor synchronous machine (WRSM) topology. The proposed topology involves two threephase stator windings with a different number of turns. Both windings are linked in parallel and are provided with current from a single inverter. One of these windings is a four-pole winding while the second winding is a two-pole winding. This arrangement generates a magneto-motive force (MMF) in the air-gap of the machine comprising of two components: a regular fundamental MMF and a sub-harmonic MMF. The fundamental component produces the main stator field whereas the sub-harmonic component generates a subharmonic field that is utilized to produce a harmonic current in a two-pole rotor harmonic winding. The induced harmonic current is rectified to inject direct current (DC) to the field winding and produce a four-pole rotor magnetic field. The four-pole rotor magnetic field when magnetically interacts with the same number of the main stator field poles producing torque. Finite element analysis (FEA) is carried out to confirm the operation and achieve the electromagnetic behavior of the proposed topology. |
| Author(s): | S. S. H. Bukhari, J.-S. Ro |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 5 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 5949 KB |
| Title: | Studying and Analysis of the Characteristic of the High-Order and MRTD and RK-MRTD Schemes |
| Abstract: | In this paper, the stability, dispersion, and convergence of the high-order FDTD (HOFDTD), the multi-resolution time-domain (MRTD), and the Runge-Kutta multi-resolution time-domain (RK-MRTD) schemes are derived, analyzed, and compared. The computational cost and memory requirements of the three methods are also investigated. It is found that the RK-MRTD method is of considerable potential due to its dispersion properties and computational abilities. |
| Author(s): | M. Zhu, Q. Cao, S. Gao |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 270 KB |
| Title: | Studying and Analysis of a Novel RK-Sinc Scheme |
| Abstract: | In this paper, a novel high-order method, Runge-Kutta Sinc (RK-Sinc), is proposed. The RK-Sinc scheme employs the strong stability preserving Runge- Kutta (SSP-RK) algorithm to substitute time derivative and the Sinc function to replace spatial derivates. The computational efficiency, numerical dispersion and convergence of the RK-Sinc algorithm are addressed. The proposed method presents the better numerical dispersion and the faster convergence rate both in time and space domain. It is found that the computational memory of the RK-Sinc is more than two times of the FDTD for the same stencil size. Compared with the conventional FDTD, the new scheme provides more accuracy and great potential in computational electromagnetic field. |
| Author(s): | M. Zhu |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 2 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1225 KB |
| Title: | Study on Time-Frequency Calculation and Analysis Method of Frequency Spectrum Characteristic of Transient Frequency Conversion Signal |
| File Type: | Conference Paper |
| Issue: | Volume: 2-SE-2 Electromagnetic Characteristics of Complex Media Simulated by Time Domain Method II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 242 KB |
| Title: | Study on the Spatial Distribution of Electromagnetic Scattering Characteristics of Radar Targets |
| File Type: | Conference Paper |
| Issue: | Volume: 3-2-E Radar Cross Section Reduction Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 187 KB |
| Title: | Study on Differential Signaling with the Decoupling Capacitor in the Rectangular Power-Bus Structure |
| File Type: | Conference Paper |
| Issue: | Volume: Applied CEM for EMC Applications Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 189 KB |
| Title: | Study on Accuracy of Direction of Arrival Estimation in FDTD Analysis of Radio Propagation Using MUSIC Method |
| File Type: | Conference Paper |
| Issue: | Volume: S20 Wave Propagation Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 330 KB |
| Title: | Study of S-shaped Structure in UWB Antenna with Dual-band Notched Characteristics |
| File Type: | Conference Paper |
| Issue: | Volume: 2-4-A Fast Numerical Analysis for Electromagnetic Radiation and Scattering Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 237 KB |
| Title: | Study of Preconditioners for RWG MoM Analysis of Large Scale Scatterers Containing Junctions with Open Surfaces and Delta-Gap Voltage Sources |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Integral Equation Methods Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 1865 KB |
| Title: | Study of Phase and Patterns Characteristics of a Sub-Wavelength Broadband Reflectarray Unit Element Based on Triple Concentric Circular-Rings |
| Abstract: | In this paper, phase and patterns characteristics of a sub-wavelength broadband reflectarray (RA) unit element are propounded. The unit element consists of triple concentric circular-rings on the Rogers 4003 substrate (H2) that provide a nearly 615 degree linear phase range. To obtain a phase curve with a lower slope, a 3 mm thick Foam (H1) is used and backed by a ground plane. A complete investigation analysis has been done to study the phase and patterns characteristics of the proposed sub-wavelength RA unit element. Results indicate that not only the incidence angle alter the element reflection phase, but also for oblique incidence, the element pattern deforms. It is shown, for sub-wavelength elements the combined effects of the mentioned factors are less severe. |
| Author(s): | J. Nourinia, C. Ghobadi, B. Mohammadi, F. Alizadeh |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 6 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2169 KB |
| Title: | Study of Phase and Patterns Characteristics of a Sub-Wavelength Broadband Reflectarray Unit Element Based on Triple Concentric Circular-Rings |
| Abstract: | In this paper, phase and patterns characteristics of a sub-wavelength broadband reflectarray (RA) unit element are propounded. The unit element consists of triple concentric circular-rings on the Rogers 4003 substrate (H2) that provide a nearly 615 degree linear phase range. To obtain a phase curve with a lower slope, a 3 mm thick Foam (H1) is used and backed by a ground plane. A complete investigation analysis has been done to study the phase and patterns characteristics of the proposed sub-wavelength RA unit element. Results indicate that not only the incidence angle alter the element reflection phase, but also for oblique incidence, the element pattern deforms. It is shown, for sub-wavelength elements the combined effects of the mentioned factors are less severe. |
| Author(s): | J. Nourinia, C. Ghobadi, B. Mohammadi, F. Alizadeh |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 6 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2171 KB |
| Title: | Study of Passive Chipless IR-UWB Indoor Positioning Based on Time-of-Arrival and Band-Notch |
| Abstract: | In the paper, a passive and chipless IR-UWB indoor positioning system is proposed that follows the criteria of spectral and temporal joint identification. In the scenario of a 2D positioning, the system is coordinated by three anchors; a node can then be positioned by recognizing the pulse’s time-of-arrival (TOA) and the pulse’s band-notch in its backscattered spectrum. The model of the positioning system is established and the numerical analysis is committed in terms of a conceived positioning example. Results validate the system that the positioning is accurate, and the accuracy can be further improved by calibrating the value of TOA through the time offset made by the pulses backscattered by the anchor with and without band-notch, respectively. |
| Author(s): | J. Liu |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 5 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1935 KB |
| Title: | Study of Equivalent Method on Second-harmonic Generation Analysis by Surface Integral Equation |
| File Type: | Conference Paper |
| Issue: | Volume: 4-2-A Advanced CEM Techniques for Complicated Problems Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 454 KB |
| Title: | Strategies for Improving the Use of the Memory Hierarchy in an Implementation of the Modified Equivalent Current Approximation (MECA) Method |
| Abstract: | In this paper, we investigate different techniques for improving the cache memory use when running a parallel implementation of the modified equivalent current approximation (MECA) method. The MECA method allows the analysis of dielectric and lossy geometries, and reduces to the well-studied physical optics (PO) formulation in case of PEC scatterers. We discuss several memory-hierarchy-based optimization techniques and present how to implement them in C. We show through simulations that these optimization strategies are effective for reducing the total execution time when calculating the scattered fields with a parallel implementation of the MECA method. |
| Author(s): | H. Gómez-Sousa, J. A. Martínez-Lorenzo, O. Rubiños-López, J. G. Meana, M. Graña-Varela, N. Gonzalez-Valdes, M. Arias-Acuña |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 10 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 360 KB |
| Title: | Stochastic Optimization of a Patch Antenna |
| Abstract: | The paper describes an efficient technique for optimizing the shape of the patch of a multi-band antenna by means of Genetic Algorithms and the hybrid FEM– RBCI method, for the analysis of open-boundary scattering and radiation electromagnetic field problems. The admissible rectangular patch area is logically and regularly subdivided into rectangular sub-areas, coinciding with the trace of the tetrahedral edge element mesh on the patch surface. In this way the relevant matrices of the finite element algebraic system, computed at the beginning of the optimization, remain unchanged, even if the patch is changed by inserting some metallic sub-areas. Moreover, in order to reduce the computing time of the iterative solver, the solution of a similar patch configuration is used as the initial guess for the solver. |
| Author(s): | S. Alfonzetti, G. Borzì, E. Dilettoso, N. Salerno, S. Alfonzetti, G. Borzì, E. Dilettoso, N. Salerno |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 3 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 115 KB |
| Title: | Stochastic Optimization of a Patch Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Poster Sessions 1 Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 211 KB |
| Title: | Stochastic Collocation for Uncertainty Quantification of Systems Described by Neutral Delayed Differential Equations |
| File Type: | Conference Paper |
| Issue: | Volume: S17 Uncertainty Quantification in CEM Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 366 KB |
| Title: | Stochastic Analysis of Multi-conductor Cables with Uncertain Boundary Conditions |
| Abstract: | This paper provides two novel Stochastic Galerkin Method strategies to undertake stochastic analysis of the crosstalk in the multi-conductor cables with uncertain boundary conditions. Two different uncertain boundary conditions, stochastic lumped source and stochastic lumped load, are considered into stochastic Transmission Line Model. With the help of the Feature Selective Validation, it is verified that the proposed strategies is accurate by comparing with the reference results provided by Monte Carlo Method. At last, advantage of the proposed strategies in computational efficiency is presented. |
| Author(s): | G. Zhang, J. Bai, L. Wang, X. Peng |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 8 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1795 KB |
| Title: | Statistical Expression for the Law of Reflection by PSO |
| File Type: | Conference Paper |
| Issue: | Volume: 4-2-E EM Theory I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 259 KB |
| Title: | Statistical Analysis of the Normalized Impedance Matrix Derived by the Random Coupling Model |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Electromagnetic Modeling Methods Part II Number: Year: 2014 |
| Download Link: | Login To Download (For Members) File Size: 318 KB |
| Title: | Statistical Analysis of Multi-Antenna Channel Capacity in the Urban Microcell Scenario |
| File Type: | Conference Paper |
| Issue: | Volume: Antenna Systems for Future Wireless Communications Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 119 KB |
| Title: | Statistical Analysis of an Electrical System within a Reverberant Cavity |
| File Type: | Conference Paper |
| Issue: | Volume: EMC in Complex Systems and Reverberant Environments Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 236 KB |
| Title: | Stability and Numerical Dispersion Analysis for A Spatially Dispersive Finite-Di®erence Time-Domain Method |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling and Applications of Microwave Metamaterial Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 186 KB |
| Title: | Stability Analysis of Discontinuous Galerkin Time-Domain Method for Conductive Media |
| File Type: | Conference Paper |
| Issue: | Volume: S06 Advanced Methods for Numerical Electromagnetic Analysis - I Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 2335 KB |
| Title: | Stability Analysis for a Flywheel Supported on Magnetic Bearings with Delayed Feedback Control |
| Abstract: | In this paper, the model of the rotor dynamics of the flywheel is given using a rigid rotor supported on magnetic bearings. The phase lag of the control loop is modeled by a simple time delay. Limits of stability and the associated vibration frequencies are described in terms of nondimensional magnetic bearing stiffness and damping and nondimensional parameters of flywheel speed and time delay. Compared to the theoretical values, the simulation results and experimental measurements show the stability boundaries of the PD controller have the same qualitative tendencies. |
| Author(s): | L. L. Zhang, J. H. Huang |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 8 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 2195 KB |
| Title: | SPEEDUP USING A MODAL FREQUENCY METHOD FOR FINITE ELEMENT ANALYSIS OF A DUAL-MODE MICROWAVE FILTER |
| Abstract: | Computer time required for finite element analysis of microwave filters is reduced by more than an order of magnitude by using modal frequency rather than direct frequency methods. In the conventional direct fre-quency method, the number of unknowns is equal to the number of edge degrees of freedom. Instead, the new modal frequency method first computes the 3D modes and then uses them as basis functions, thereby greatly reduc-ing the number of degrees of freedom. The two methods are applied to the European benchmark problem of a dual-mode microwave filter. The modal frequency meth-od obtains essentially the same results as the direct fre-quency method, but when analyzing 201 frequencies it yields a speedup factor of 15. |
| Author(s): | John R. Brauer, John R. Brauer |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 2 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 927 KB |
| Title: | Spectral Properties and Regularization of Loop, Star, and Tree Related Gram Matrices |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Advances in Integral Equations and Fast Methods Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 940 KB |
| Title: | Spectral Analysis of Synthetic Electrode Activations in Adaptive Capacitance Volume Tomography |
| File Type: | Conference Paper |
| Issue: | Volume: S37 Remote Sension and Imaging Applications Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 359 KB |
| Title: | Spectral Analysis of Negative Refractive Index Metamaterials Utilizing Signal Processing Techniques and Time-Domain Simulations |
| File Type: | Conference Paper |
| Issue: | Volume: Metamaterials Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 233 KB |
| Title: | Spectra of Finite Element Matrix for Magnetostatic and Quasi-static Electromagnetic Fields |
| File Type: | Conference Paper |
| Issue: | Volume: Japanese Research in Electromagnetic Field Computations Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 204 KB |
| Title: | Spatial Domain Generation of Random Surface Using Savitzky-Golay Filter for Simulation of Electromagnetic Polarimetric Systems |
| Abstract: | A spatial-domain algorithm is introduced for generating both isotropic and anisotropic natural rough surface models with predetermined statistical properties using Savitzky-Golay filter. Unlike the spectral-domain methods, the proposed method does not require the calculation of two-dimensional inverse Fourier transforms which constitute a computational burden for generating large ensembles of high-resolution surfaces. A comparative analysis between the proposed spatial-domain method and one of the conventional spectral-domain methods is presented. The comparison shows that the proposed spatial-domain method results in substantially improved computational performance. The fitness of the generated rough surface to the predetermined statistical properties is verified by calculating a variogram for numerical measurement of the variance and the correlation lengths. To demonstrate the importance of generating such a rough surface for simulation of electromagnetic polarimetric systems, a rough surface with anisotropic statistical properties is placed in the near field region of two antennas of orthogonal polarizations. It is shown that the self and mutual electromagnetic coupling coefficients of the two antennas can be used for measuring the orientation of the rough surface. |
| Author(s): | S. A. M. Soliman, A. E. Farahat, K. F. A. Hussein, A.-E.-H. A. Ammar |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 3159 KB |
| Title: | Space-Fed Antenna Array Design and Analysis Package |
| File Type: | Conference Paper |
| Issue: | Volume: S06 Electromagnetics and Antenna Education Number: Year: 2015 |
| Download Link: | Login To Download (For Members) File Size: 736 KB |
| Title: | Space-Fed Antenna Array Design and Analysis Package |
| File Type: | Conference Paper |
| Issue: | Volume: S09 Student Paper Competition Number: Year: 2015 |
| Download Link: | Login To Download (For Members) File Size: 736 KB |
| Title: | Space Antenna Feed Design at ALCATEL ALENIA SPACE (F) |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Antenna Applications Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 195 KB |
| Title: | Solving Maxwell’s Equations with a Generalized Dispersive Material Model on Overset Grids |
| File Type: | Conference Paper |
| Issue: | Volume: S13 Advanced Time Domain Solvers for Multiphysics Modeling in Photonics Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 793 KB |
| Title: | SOLUTION OF TEAM BENCHMARK PROBLEM #9 (Handling Velocity Effects with Variable Conductivity) |
| Abstract: | Users often raise the question of whether it is possible to analyze eddy current problems with velocity effects within codes that are not programmed to account for movement. This paper looks at a technique for applying a conventional boundary element technique to the analysis of a velocity induced eddy current by altering the conductivity of the conducting medium as a function of position. Results of the predicted B fields for v=0 m/s and v=10 m/s are compared to the analytical solution of a coil traveling axially down the center of a conducting tube. Good agreement is achieved; further refinement could be realized by iterating on conductivity if necessary. [Vol. 8, No. 2 (1993), Special Section in Team Benchmark Problem Solutions, pp 232-243] |
| Author(s): | Kent Davey, Kent Davey |
| File Type: | Journal Paper |
| Issue: | Volume: 8 Number: 2 Year: 1993 |
| Download Link: | Click here to download PDF File Size: 483 KB |
| Title: | Solution of Large Complex Problems on 32-bit Desktop/Laptop Computers Using an Efficient and Accurate Out-of-Core Solver |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Electromagnetic Modeling by WIPL-D Software Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 276 KB |
| Title: | Slot Filling Factor Calculation and Electromagnetic Performance of Single Phase Electrically Excited Flux Switching Motors |
| Abstract: | For variable speed applications, flux controlling capability of electrically excited flux switching motors (EEFSMs) attract researchers’ attention. However, low copper slot filling factor of the EEFSM with standard stator slot vitiates the electromagnetic performance and efficiency. This paper has proposed a new Octane Modular Stator (OMS) EEFSM model that has pentagonal stator slot and high copper slot filling factor. Copper slot filling factor is deliberated analytically for the proposed model and designs with standard stator slots, i.e., trapezoidal and rectangular. Electromagnetic performance of the OMS, Rectangular Stator Slot (RSS) and Trapezoidal Stator Slot (TSS) EEFSM designs are evaluated by finite element analysis (FEA) through JMAG v18.1 FEA solver. The proposed OMS EEFSM model has 9% higher copper slot filling factor in comparison with standard stator slots designs under same geometric parameters. The high copper slot filling factor of the proposed OMS EEFSM model has improved performance in term of low electric and magnetic loading. |
| Author(s): | B. Khan, F. Khan, W. Ullah, M. Umair, S. Hussain |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 8 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 2763 KB |
| Title: | Slit-Loaded Hexagonal Patch for Body Area Network Applications at 5.8 GHz |
| Abstract: | Increasing population and expanding remote healthcare monitoring needs have provided an impetus to the research and development of wireless devices. The quest for smaller antennas for wireless devices has led to the design of the proposed antenna. In this work, we present a slit-loaded hexagonal patch antenna for body area network applications. The antenna has been designed on a 0.193λ×0.193λ×0.03λ FR4-epoxy substrate. The radiator patch has two parallel slits. The antenna resonates at 5.8 GHz (ISM band) with a wide bandwidth of 1.15 GHz. A maximum gain of 5.81 dB and a front-to-back ratio of 11.93 dB is observed at 5.8 GHz. Radiation efficiency is observed to be 72.3%. The measured return loss values show a close agreement with the simulated results. Specific absorption rate (SAR) analysis on a simplified 2/3rd muscle model shows an average SAR of 0.5633 W kg-1, due to the use of a full-ground plane. The simulations were done in ANSYS HFSS. The antenna is suitable for on-body communications. |
| Author(s): | S. Mahapatra, M. N. Mohanty |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 11 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2286 KB |
| Title: | SLF/ELF Electromagnetic Field of a Horizontal Dipole in the Presence of an Anisotropic Earth-Ionosphere Cavity |
| Abstract: | In this paper, the region of interest is a cavity between a spherical and electrically homogeneous earth and an anisotropic homogeneous ionosphere. Both the dipole (Vertical Electric Dipole (VED), Vertical Magnetic Dipole (VMD), or Horizontal Electric Dipole (HED)) and the observation point are assumed to be located on or near the spherical surface of the earth. The approximate formulas are obtained for the electromagnetic field of a vertical magnetic dipole and that of a vertical electric dipole in the presence of an anisotropic earthionosphere cavity, respectively. Based on the results obtained, the approximate formulas are derived readily for the electromagnetic field of a horizontal electric dipole in the presence of an anisotropic earth-ionosphere cavity by using a reciprocity theorem. Analysis and computations in SLF/ELF ranges are carried out specifically. |
| Author(s): | G. Z. Li, T. T. Gu, K. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 12 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 488 KB |
| Title: | Six-Channel Diplexer using Stub-Loaded Stepped Impedance Resonators |
| Abstract: | In this paper, a compact six-channel diplexer with low insertion loss and high isolation level is presented. The diplexer consists of two tri-band bandpass filters (BPFs), two meander transmission lines and hookshaped feeding lines. The BPFs are designed based on stub-loaded stepped impedance resonators (SLSIRs). Based on even- and odd-mode (EOM) analysis of the resonator, there are two resonant modes that operate at the same frequency. For splitting the two modes, stubstub coupling is employed here. The combination of the two BPFs is implemented by utilizing two meander transmission lines as the impedance matching network. Finally the proposed diplexer operating at 1.46/1.74/2.96 GHz (for Load 1) and 0.89/1.15/2.40 GHz (for Load 2) is fabricated and measured. A good agreement between simulated and measured results evidently validates the proposed diplexer. |
| Author(s): | J. Liu, T. Su, H. Lv, L. Lin, B. Wu |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 10 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1678 KB |
| Title: | Singly-Fed Circularly Polarized Electromagnetically Coupled Patch Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Analysis and Design of Antennas for Wireless Communications Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 215 KB |
| Title: | Using Folded Open-Loop Ring Resonator to Design a Common-Mode Suppression and Frequency Adjustable Balun-Bandpass Filter |
| Abstract: | A compact and simple balun-bandpass filter was investigated by using a pair of half-wavelength open-loop ring resonators (OLRRs) and two microstrip lines. The balun-bandpass filter could be designed easily with a different center frequency by changing the path length of OLLRRs. The design methodology was adopted based on EM simulation to obtain these optimally designed parameters of the OLRRs, and microstrip lines and the filters were fabricated on FR4 substrate. The filters with the frequencies of 2.6 GHz and 5.2 GHz were designed to prove the characteristic of frequency adjustable and they were fabricated with the properties of wide bandwidth and low insertion loss. The balun-bandpass filters presented an excellent inband balanced performance with common-mode rejection ratio over than 40 dB and 34 dB in the passbands of 2.6 GHz and 5.2 GHz, respectively. Good correlation was seen between simulation and measurement, and the result showed that first run pass had been achieved in the majority of our design. |
| Author(s): | C.-M. Chen, S.-J. Chang, J.-C. Zheng, J.-C. Liou, C.-F. Yang |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 1 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 691 KB |
| Title: | Using Electromagnetic Band Gap (EBG) Superstrate Layer to Enhance the Bandwidth and Gain of a Dual Band Microstrip Patch Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Metamaterial Structures with Application to Guided-Wave Electromagnetics and Antennas Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 182 KB |
| Title: | Using Adaptive Estimation to Minimize the Number of Samples Needed to Develop a Pattern to a Specified Uncertainty |
| Abstract: | Obtaining far-field patterns in electromagnetics or acoustics, although generally not as computationally expensive as solving for the sources induced on an object, can none-the-less at times be a substantial fraction of the overall computer time associated with some problems. This can be especially the case in determining the monostatic radar cross section of large objects, since the current distribution must be computed for each incidence angle or when using physical optics to determine the radiation patterns of large reflector antennas. In addition, when employing the point sampling and linear interpolation of the far field that is most often used to develop such patterns, it can be necessary to sample very finely in angle to avoid missing fine details such as nulls. A procedure based on model-based parameter estimation is described here that offers the opportunity of reducing the number of samples needed while developing an easily computed and continuous representation of the pattern. It employs windowed, low-order, overlapping fitting models whose parameters are estimated from the sparsely sampled far-field values. The fitting models themselves employ either discrete-source approximations to the radiating currents or Fourier models of the far field. For the cases investigated, as few as 1.5 to 2 samples per far-field lobe are found to be sufficient to develop a radiation-pattern estimate that is accurate to 0.1 dB, and 2.5 samples per lobe for a simple scatterer. In general, however, the sampling density is not determined by the lobe count alone, but by the effective rank of the field over the observation window, which in turn is a function of both the aperture size and the spatial variation of the source distribution within that aperture. |
| Author(s): | Edmund K. Miller, Edmund K. Miller |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 3 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 278 KB |
| Title: | Using a Radial, Switchable, Sector Ground Screen to Produce Azimuthal Directivity for a Monopole Antenna |
| Abstract: | Ground-mounted monopole antennas are usually driven against a radial-wire ground system to control their input impedance and to improve their radiation efficiency. This results in a radiation pattern that is uniform in azimuth angle with a front-to-back ratio of 1, or 0 dB. The use of a sectorial ground screen, one whose radial or angular extent is varied to produce a radiation pattern having azimuthal directivity has received some attention. An alternate approach also is explored in this discussion. It involves exploring the effect of varying the number of “active” radials in an otherwise uniform ground system of radial wires, an active radial being one that is electrically connected to the base of the monopole. A “passive” radial on the other hand is one that is separated from the monopole by a switch. By varying the number and angular locations of the active and passive ground wires, the resulting azimuth pattern can be varied in angle and directive gain. This arrangement makes possible a steerable pattern, something not usually associated with ground-mounted monopoles. The antenna and ground screen are modeled using the well-known NEC package. For convenience in modeling, active radials are made into passive ones by adding a large resistance between the base of the monopole and a given radial. Directive gains of more than 5 dB are found to be possible. |
| Author(s): | E. K. Miller |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1549 KB |
| Title: | User’s Hand Effects on Built-in L-shaped Folded Monopole Antenna for Mobile Handsets |
| File Type: | Conference Paper |
| Issue: | Volume: Antenna Modeling and Small Antennas Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 1367 KB |
| Title: | Use of Model-Based Parameter Estimation in Electromagnetic Scattering Problems of a Conducting Body of Revolution |
| File Type: | Conference Paper |
| Issue: | Volume: Hybrid Techniques in Computational Electromagnetics Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 133 KB |
| Title: | Use of Model-Based Parameter Estimation for Fast RCS Computation of a Conducting Body of Revolution over a Frequency Band |
| Abstract: | Abstract—Frequency-derivative information incorporated with model-based parameter estimation (MBPE) is used to obtain scattering from a perfectly conducting body of revolution (BOR). The electric field integral equation (EFIE) is solved using the method of moments (MoM) to obtain the surface current on the perfectly conducting body. Instead of computing the MoM solution using a pointwise approach, a rational function model is used to approximate the current as a function of frequency. The model coefficients are computed using both frequency and frequency-derivative information at one frequency in the band or alternatively two or more frequencies in the band. With the rotational symmetry of BOR, the computational cost can be significantly reduced compared to that of arbitrary three-dimensional (3-D) objects and more importantly scattering from an electrically large body can be obtained. Numerical results for various perfectly conducting bodies are presented. Results show that the MBPE provides excellent agreement with the pointwise approach over a limited frequency band. In addition, the MBPE performs well for predicting sharp resonances. |
| Author(s): | Hyunwung Son, Joseph R. Mautz, Ercument Arvas, Hyunwung Son, Joseph R. Mautz, Ercument Arvas |
| File Type: | Journal Paper |
| Issue: | Volume: 19 Number: 1 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 437 KB |
| Title: | Use of Hanging Variables for Nested h Refinement in 2D FETD |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Finite Element Technique and its Applications Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 879 KB |
| Title: | Use of Dielectric Spectroscopy for the Study of Concentration of Glyphosate in Distilled Water |
| File Type: | Conference Paper |
| Issue: | Volume: S14 Numerical Methods for Diverse Applications Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 495 KB |
| Title: | Use of Dielectric Spectroscopy for the Study of Concentration of Glyphosate in Distilled Water |
| Abstract: | In this paper, the capability of sensing low concentrations of glyphosate in water of two interdigital capacitive transducers are analyzed using numerical simulations and measurements. Each microwave sensor is analyzed using the surface electric field produced at the resonance frequency. In addition, the reflection coefficient of each transducer submerged in water with glyphosate is measured and compared with distilled water. Prepared samples with concentrations of 1ppm/L (1 part per million over a liter of distilled water) are used for the experimental tests. |
| Author(s): | C. Mendivelso, J. J. Pantoja, F. Vega, C. Kasmi, F. Al Yafei |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1454 KB |
| Title: | USE OF A STEALTH BOUNDARY WITH FINITE DIFFERENCE FREQUENCY DOMAIN SIMULATIONS OF SIMPLE ANTENNA PROBLEMS |
| Abstract: | A direct method for the numerical solution of Maxwell's equations in the frequency domain (sinusoidal steady state), for radiation problems of cylindrical symmetry, is incorporated into a finite difference program called HERZ, coded in FORTRAN. The termination of the fields on the outer boundary of the problem domain is accomplished via an absorptive layer, labelled a stealth layer, which attenuates the incident fields to insignificant amounts in a small computing space, without causing significant reflections that would disturb the near field solutions. No radiation boundary condition is specified on the problem domain, rather, the transmission of the fields to the stealth layer is optimized by specifying its electrical properties. To validate HERZ as a useful electromagnetic modeller for thin wire antennas, driving point admittances and surface current distributions for several configurations were compared to both theoretical and measured values, with good agreement. [Vol. 9, No. 1 (1994), pp 78-87] |
| Author(s): | R.B. Thompson, F.S. Chute, F.E. Vermeulen, R.B. Thompson, F.S. Chute, F.E. Vermeulen |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 1 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 794 KB |
| Title: | Unsplit-Field Implementation of the Higher-Order PML using Z-Transform Method and D-B Formulation for Arbitrary Media |
| Abstract: | On the basis of the stretched coordinate perfectly matched layer (SC-PML) formulations, the Z-transform method, and D-B formulation, an efficient and unsplit-field implementation of the higher-order PML scheme with more than one pole is proposed to truncate the finite-difference time-domain (FDTD) lattices. This method is completely independent of the material properties of the FDTD computational domain and hence can be applied to the modeling of arbitrary media without any modification. The higher-order PML has the advantages of both the conventional PML and the complex frequency shifted PML (CFS-PML) in terms of absorbing performances. The proposed algorithm is validated through two numerical tests carried out in three dimensional and two dimensional domains. It is shown in the numerical tests that the proposed PML formulations with the higher-order scheme are efficient in terms of attenuating both the low-frequency propagating waves and evanescent waves and reducing late-time reflections, and also hold much better absorbing performances than the conventional SC-PML and the convolutional PML (CPML) with the CFS scheme. |
| Author(s): | N. Feng, J. Li, X. Zhao |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 3 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 288 KB |
| Title: | Unmanned Aerial Vehicle Platform Stabilization for Remote Radar Life Sensing |
| Abstract: | Unmanned Aerial Vehicle (UAV) platforms are increasingly ubiquitous and an ideal platform for rapid deployment to conduct remote sensing. However, for radar sensors that measure the phase of the signal of interest, the platform must be stabilized to avoid signal distortion. Measurement of respiratory motion with a continuous wave Doppler radar sensor is vulnerable to platform motion and requires a stable platform and post-detection motion compensation signal processing. We have investigated feedback stabilization techniques via simulation and empirical measurements using a bench top test fixture to remove the motion noise, where we observed a 86% reduction in motion, resulting in a SNR improvement of 29 dB after motion compensation. |
| Author(s): | R. H. Nakata, B. Haruna, S. K. Clemens, D. Martin, C. Jaquiro, V. M. Lubecke |
| File Type: | Express Journal Paper |
| Issue: | Volume: 1 Number: 5 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2417 KB |
| Title: | Unmanned Aerial Vehicle Platform Stabilization for Remote Radar Life Sensing |
| Abstract: | Unmanned Aerial Vehicle (UAV) platforms are increasingly ubiquitous and an ideal platform for rapid deployment to conduct remote sensing. However, for radar sensors that measure the phase of the signal of interest, the platform must be stabilized to avoid signal distortion. Measurement of respiratory motion with a continuous wave Doppler radar sensor is vulnerable to platform motion and requires a stable platform and postdetection motion compensation signal processing. We have investigated feedback stabilization techniques via simulation and empirical measurements using a bench top test fixture to remove the motion noise, where we observed a 86% reduction in motion, resulting in a SNR improvement of 29 dB after motion compensation. |
| Author(s): | R. H. Nakata, B. Haruna, S. K. Clemens, D. Martin, C. Jaquiro, V. M. Lubecke |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1838 KB |
| Title: | Unmanned Aerial Vehicle Platform Stabilization for Remote Radar Life Sensing |
| Abstract: | Unmanned Aerial Vehicle (UAV) platforms are increasingly ubiquitous and an ideal platform for rapid deployment to conduct remote sensing. However, for radar sensors that measure the phase of the signal of interest, the platform must be stabilized to avoid signal distortion. Measurement of respiratory motion with a continuous wave Doppler radar sensor is vulnerable to platform motion and requires a stable platform and postdetection motion compensation signal processing. We have investigated feedback stabilization techniques via simulation and empirical measurements using a bench top test fixture to remove the motion noise, where we observed a 86% reduction in motion, resulting in a SNR improvement of 29 dB after motion compensation. |
| Author(s): | R. H. Nakata, B. Haruna, S. K. Clemens, D. Martin, C. Jaquiro, V. M. Lubecke |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1838 KB |
| Title: | Unitary Matrix Pencil Method for Sparse Linear Array Pattern Synthesis |
| File Type: | Conference Paper |
| Issue: | Volume: 2-3-B Modeling, Design and Optimization of Modern Antennas Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 269 KB |
| Title: | Unilateral Amplifier S-Parameter Extraction Technique |
| File Type: | Conference Paper |
| Issue: | Volume: Design and Analysis of Advanced Circuit Architectures Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 179 KB |
| Title: | Uniform Theory of Diffraction Approximation for Large Antenna Array Fields |
| File Type: | Conference Paper |
| Issue: | Volume: S36 Antenna Design II Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 503 KB |
| Title: | Uniform Sampling Procedure for Constrained Surrogate Modeling of Antenna Structures |
| File Type: | Conference Paper |
| Issue: | Volume: S33 Electromagnetic Simulation for RF and Microwave Design Optimization Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 274 KB |
| Title: | Ungrounded Lightning Surge Protection Device for Wireless Sensor Networks Node in the Wilderness |
| Abstract: | In the wilderness, the use of wireless sensor network (WSN) nodes because of their maintenance-free remote-monitoring characteristic demands ungrounded lightning surge protection. This paper proposes a design of a protection device with functions of low-frequency surge cutting off and radio-frequency (RF) signal passing. In this device, the discharge circuit consists of a threelevel surge by-pass circuit, an outer conductor antenna, and a copper-clad circuit board. The current capacity, start time, and output voltage meet the requirements of surge protection for a weak current device. Discrete components that provide the protective feature were involved in calculating impedance matching, and the parameters of these components were estimated and adjusted constantly at the test stage to ensure that the impedance of the inserted protection device matches with those of the node RF transceiver module and antenna. The experimental results show that the node with the ungrounded protection device can pass fourth-level surge immunity experiments and run for 49 months at the outdoor monitoring site in the Xinjiang coal fire area. |
| Author(s): | Q. Cao, L. Yang, S. Yan |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 3 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1412 KB |
| Title: | Unequal Y-Power Divider Kron-Branin Model |
| File Type: | Conference Paper |
| Issue: | Volume: 2-P2-C RFID Antennas and Systems Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 291 KB |
| Title: | Understanding the Electromagnetic Characteristics of Real Metamaterials via Rigorous Field Simulation |
| File Type: | Conference Paper |
| Issue: | Volume: Metamaterial Structures with Application to Guided-Wave Electromagnetics and Antennas Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 172 KB |
| Title: | Underground Localization System using a Combination of RFID and IMU Technologies |
| File Type: | Conference Paper |
| Issue: | Volume: S24 Student Paper Competition - I Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 1427 KB |
| Title: | Underground Localization System using a Combination of RFID and IMU Technologies |
| File Type: | Conference Paper |
| Issue: | Volume: S37 Advanced Optimization of Electromagnetic Structures - II Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 1427 KB |
| Title: | Unconventional Array for 5G Scenario: Irregular Clustering Antenna Design and Implementation |
| File Type: | Conference Paper |
| Issue: | Volume: 8-TP-5 Unconventional Array Analysis and Synthesis for New Generation Communications and Sensing Systems I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 283 KB |
| Title: | Unconventional Array for 5G Scenario: Irregular Clustering Antenna Design and Implementation |
| File Type: | Conference Paper |
| Issue: | Volume: 10-TE-5 Unconventional Array Analysis and Synthesis for New Generation Communications and Sensing Systems II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 283 KB |
| Title: | Unconditionally-Stable Meshless Methods Using Different Split-Step Techniques and Their Phase Velocity Considerations |
| Abstract: | In this paper, new unconditionallystable meshless methods based on different splitstep methods are proposed. Moreover, comparison of the phase velocities of two different split-step meshless methods and that of alternativedirection- implicit meshless (ADI-ML) method is presented. Here we show how employing splitstep (SS) technique using radial point interpolation meshless (RPIM) method results in an unconditionally stable scheme. Symmetric operators and uniform splitting are utilized simultaneously to split the classical Maxwell’s matrix into four and six submatrices. Also, for more accurate approximations Crank-Nicolson (CN) scheme that is a fully implicit scheme has been applied for implementation of these schemes. It has been demonstrated, these proposed methods produce even more effective unconditionally stable responses than those of alternatingdirection- implicit meshless time-domain ADIMLTD methods. Eventually, in order to prove the advantage of the proposed method, a comparison has been made between these novel meshless methods and their finite-difference counterparts. More smoothed phase velocities in proposed meshless methods imply a reduction in dispersion error in comparison with their analogous cases in finite-difference time-domain (FDTD) method. |
| Author(s): | F. Ansarizadeh, M. Movahhedi |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 9 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 354 KB |
| Title: | Uncertainty Quantification of the Crosstalk in Multiconductor Transmission Lines via Degree Adaptive Stochastic Response Surface Method |
| Abstract: | The degree adaptive stochastic response surface method is applied to analyze statistically the crosstalk in multiconductor transmission lines (MTLs). The coefficient of polynomial chaos expansion (PCE) is obtained based on the least angle regression. The truncation degree of PCE is iterated using the degree adaptive truncation algorithm, and the optimal proxy model of the crosstalk of the original MTLs that satisfies the actual error requirements is calculated. The statistical properties of crosstalk in MTLs (such as mean, standard deviation, skewness, kurtosis, and probability density distribution) are obtained. The failure probability of the electromagnetic compatibility in the MTLs system is considered. The global sensitivity indices of crosstalkrelated factors are analyzed. Finally, the proposed method is proved to be effective compared with the conventional Monte Carlo method. The uncertainty quantification of crosstalk in MTLs can be calculated efficiently and accurately. |
| Author(s): | Q. Yu, W. Liu, K. Yang, X. Ma, T. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 2 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1551 KB |
| Title: | Uncertainty Quantification in Transcranial Magnetic Stimulation with Correlation Between Tissue Conductivities |
| File Type: | Conference Paper |
| Issue: | Volume: S17 Uncertainty Quantification in CEM Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 1019 KB |
| Title: | Uncertainty Quantification and Optimal Design of EV-WPT System Efficiency based on Adaptive Gaussian Process Regression |
| Abstract: | Wireless power transfer (WPT) is a safe, convenient, and intelligent charging solution for electric vehicles. To address the problem of the susceptibility of transmission efficiency to large uncertainties owing to differences in coil and circuit element processing and actual driving levels, this study proposes the use of adaptive Gaussian process regression (aGPR) for the uncertainty quantification of efficiency. A WPT system efficiency aGPR surrogate model is constructed with a set of selected small-sample data, and the confidence interval and probability density function of the transmission efficiency are predicted. Finally, the reptile search algorithm is used to optimize the structure of the WPT system to improve efficiency. |
| Author(s): | X. Shang, L. Xu, Q. Yu, B. Li, G. Lv, Y. Chi, T. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 12 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 6360 KB |
| Title: | Uncertainty Problem as Illustrated by Magnetotherapy |
| Abstract: | This article presents the impact of fixed tissue conductivities on the distribution of eddy currents in human body. Electrical conductivities characterising human tissues present in limbs have been collated based on various publications from the last 25 years. The article shows the extent to which simulation results are affected by changes to electrical conductivity of specific tissues. It has been demonstrated that the tissues taking the largest part of the studied domain have the greatest impact. The conclusions from these results suggest that it is very important to determine the electrical conductivity of tissues forming the human body with increasing precision, as it is an important factor affecting the accuracy of results. This factor seems much more significant than the growth in the precision of models resulting from increasing resolution of numerical models made available for research purposes. |
| Author(s): | P. Syrek |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 9 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1737 KB |
| Title: | Uncertain Material Parameter Extraction using FEKO Optimizations for Space Applications |
| File Type: | Conference Paper |
| Issue: | Volume: S05 EM Modeling Using Feko - I Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 259 KB |
| Title: | Ultrawideband Printed Elliptical Monopole Antenna With Four Band- Notch Characteristics |
| File Type: | Conference Paper |
| Issue: | Volume: Antenna Modeling, Simulation, and Validation Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 150 KB |
| Title: | Ultrawideband Antipodal Vivaldi Antenna for Road Surface Scanner Based on Inverse Scattering |
| File Type: | Conference Paper |
| Issue: | Volume: Student Projects in Sonnet Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 311 KB |
| Title: | Ultrabroadband Polarization-insensitive Far-infrared Metameterial Absorber by Gold Nanowire Array |
| File Type: | Conference Paper |
| Issue: | Volume: 2-1-C Properties, Modelling and Novel Concepts of Artificial Electromagnetic Structures I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 351 KB |
| Title: | Ultra-wideband Triple-Ellipse Inverted-Hat Antenna for Aircraft Communications |
| File Type: | Conference Paper |
| Issue: | Volume: FEKO Modeling and Analysis I Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 244 KB |
| Title: | Ultra-wideband Transmissive Linear Polarization Device Based on Graphene |
| Abstract: | In order to achieve both adjustable wideband and high Polarization Conversion Rate (PCR) of the transmitted waves, a novelty tri-layered structure is proposed for terahertz applications. The Rhombus Hollow Square (RHS) is built up by top and bottom gold gratings on Silicon Dioxide and Polyamide substrate with graphene strips. The proposed polarizer broadens the bandwidth and has well performance. As chemical potential increases, the bandwidth is also broadened by adjusting the graphene. From 0.5 THz to 3 THz, the PCR is greater than 90%, and the relative bandwidth up to 142.9%. The transmission and absorption of polarizer are analyzed at the oblique incidence with chemical potential 0.1eV. By simulating and analyzing the performance, a new result of maintaining broadband and high transmittance in oblique incidence is obtained. |
| Author(s): | L. Guo, S. Li, X. Jiang, X. Liao, L. Peng |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 7 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1612 KB |
| Title: | Ultra-wideband Terahertz Absorber Based on E Shape Graphene Pattern |
| Abstract: | We present a tunable ultra-wideband (UWB) absorber based on a multilayer of “E” shaped graphene patterns. The numerically calculated results indicate that the absorption of the proposed design is above 95% in the range of 1.12 to 14.04 THz. By using the multiple layers of graphene, the relative bandwidth is 95% and reaches up to 170% of the central frequency. Furthermore, for transverse electric polarization mode at a resonating frequency of 1.68, 3.99, 7.51, 13.56, and 17.74 THz the absolute value exceeds 99.57, 99.37, 99.94, 99.86, and 99.09%, respectively. Also, owing to the structure’s rotational symmetry, the absorber is insensitive to both transverse magnetic (TM) and transverse electric (TE) polarization. The absorption peaks and frequency band can be controlled effectively by altering the Fermi level of graphene without modifying the structure manually. Moreover, the absorber exhibits steady absorption over an incident angle of 0° to 60°, with just a minor decrease in bandwidth around 60°. |
| Author(s): | M. Sajjad, X. Kong, S. Liu, S. U. Rahman, Z. Khan, Owais |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 2 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 1182 KB |
| Title: | Ultra-Wideband Reflectarray with Multi-Resonance Elements |
| File Type: | Conference Paper |
| Issue: | Volume: 2-2-B Millimeter Wave and Terahertz Antennas Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 287 KB |
| Title: | Ultra-Wideband Polarization Conversion Metasurface Based on Topology Optimal Design and Geometry Tailor |
| Abstract: | We presented a topology optimization method based on genetic algorithm (GA) combined geometry tailor scheme (GTS) to realize ultra-wideband polarization conversion metasurfaces (UPCM) in microwave range. The present method takes the connectivity condition of the elements into consideration, thereby resulting in good optimization efficiency. As examples, a UPCM is designed by topology optimization, which is composed of the dielectric substrate sandwiched with patched metallic patterns and continuous metal background. Three plasmon resonances are generated by electric and magnetic resonances, which lead to bandwidth expansion of cross-polarization reflection. The simulated results show that the maximum conversion efficiency is nearly 100% at the three plasmon resonance frequencies and the 3 dB bandwidth range from 5.66 to 24.68 GHz can be achieved for both normally incident x- and y-polarized waves. |
| Author(s): | S. Sui, J. Yu, H. Ma, J. Zhang, J. Wang, Z. Xu, S. Qu |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 7 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1774 KB |
| Title: | Ultra-wideband Planar Log-periodic Slot Antenna with Exponential Shapes on Slot Edges |
| Abstract: | An improved method of using exponential curve shape on edges of log-periodic slots to decrease resonances and further reduce the antenna size is proposed. The proposed method is adopted to design a planar log-periodic slot antenna for ultra-wideband (UWB) applications. Numerical investigation shows that resonant frequencies can be decreased around 12.3% in low frequencies compared with the conventional planar log-periodic slot antenna with regular shape on edges of slots. Measured and simulated reflection coefficients and radiation patterns of the proposed antenna agree well with each other to demonstrate the validity. The measured |S11| shows that the operating frequency range (|S11| below -10 dB) is from 2.9 GHz to 11.36 GHz, covering the UWB spectrum (3.1 – 10.6 GHz). The proposed antenna has good radiation characteristics and antenna gains. The proposed antenna is a good candidate for the UWB applications. |
| Author(s): | W.-C. Weng, M.-C. Chang |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 9 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1944 KB |
| Title: | Ultra-Wideband Planar Antenna with Notched Bands at 3.5/5.5 GHz |
| Abstract: | In this paper, a microstrip planar antenna with notch bands at 3.5/5.5 GHz is proposed for ultra- wideband communication. An e-shape parasitic slit and an inverted C-shape slit are imprinted beneath the radiating patch to generate notch bands to suppress the interference from WiMAX and WLAN respectively. The experimental results confirmed that the fabricated prototype with a very small size has achieved an UWB operating band for VSWR ? 2 with two notched bands covering frequencies of 3.32 - 3.76 GHz and 5.2 - 5.92 GHz. The presented design achieved a good gain except at notched bands and exhibits stable omnidirectional radiation patterns. In this design, filter elements are embedded only on one side of the substrate without cutting any slot/s in the radiating element/ground plane and no modification of the patch or the ground plane is required which gives the proposed design an advantages over many designs reported for the same applications. |
| Author(s): | R. Azim, M. T. Islam |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 4 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 638 KB |
| Title: | Ultra-Wideband Offset Bicone/Dipole Antenna: Simulations and Measurements |
| File Type: | Conference Paper |
| Issue: | Volume: Antenna Modeling Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 379 KB |
| Title: | Ultra-Wideband Modified CSRR Antenna with Reconfigurable Notch Band |
| Abstract: | A novel technique of realizing notches for a compact ultra-wideband (UWB) antenna is proposed based on a modified complementary split ring resonator (CSRR). The UWB slot antenna is in the swallow shape of a modified CSRR. The notched band centered at 5.8 GHz for upper WLAN and 3.9 GHz for C-band satellite communication systems. The proposed antenna has a compact size of 25 × 27.9 mm2. The measured results show that the proposed antenna can guarantee a wide bandwidth from 2 GHz to 12 GHz (VSWR < 2) with dual unwanted bandnotches successfully. The antenna demonstrates omnidirectional and stable radiation patterns across all the relevant bands. Moreover, a prototype of the dual-band-notched UWB antenna is fabricated and measured results are compared with simulated results. |
| Author(s): | D. Jiang, B. Yan, R. Xu |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 7 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 1496 KB |
| Title: | Ultra-Wideband Microstrip Antenna for Body Centric Communications |
| Abstract: | A novel low profile reconfigurable wide band microstrip antenna for impulse radio ultra-wideband (IR-UWB) WBANs and targeted for on-body sensor node has been introduced. The printed monopole antenna consists of a heart shaped radiating patch and an elliptical ground plane. This antenna has a frequency bandwidth of 130% with a VSWR of 1.5 and average gain is about 3.6 dBi. There is a slot on the patch which is loaded by two varactor diodes to form a tunable notch band. The antenna operates from 2.4 GHz to 12 GHz. The proposed antenna is a good candidate for medical purpose since it has a sufficient amount of gain and bandwidth. We used active circuit to increase the flexibility of setting rejection band to prevent having interference from other sources such as Wi-Fi. The antenna is fabricated and there is a good agreement between the simulation and measurement results. |
| Author(s): | A. Darvazehban, T. Rezaee |
| File Type: | Express Journal Paper |
| Issue: | Volume: 1 Number: 9 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1530 KB |
| Title: | Ultra-Wideband Microstrip Antenna for Body Centric Communications |
| Abstract: | A novel low profile reconfigurable wide band microstrip antenna for impulse radio ultra-wideband (IRUWB) WBANs and targeted for on-body sensor node has been introduced. The printed monopole antenna consists of a heart shaped radiating patch and an elliptical ground plane. This antenna has a frequency bandwidth of 130% with a VSWR of 1.5 and average gain is about 3.6 dBi. There is a slot on the patch which is loaded by two varactor diodes to form a tunable notch band. The antenna operates from 2.4 GHz to 12 GHz. The proposed antenna is a good candidate for medical purpose since it has a sufficient amount of gain and bandwidth. We used active circuit to increase the flexibility of setting rejection band to prevent having interference from other sources such as Wi-Fi. The antenna is fabricated and there is a good agreement between the simulation and measurement results. |
| Author(s): | A. Darvazehban, T. Rezaee |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 3 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1815 KB |
| Title: | Ultra-Wideband Microstrip Antenna for Body Centric Communications |
| Abstract: | A novel low profile reconfigurable wide band microstrip antenna for impulse radio ultra-wideband (IRUWB) WBANs and targeted for on-body sensor node has been introduced. The printed monopole antenna consists of a heart shaped radiating patch and an elliptical ground plane. This antenna has a frequency bandwidth of 130% with a VSWR of 1.5 and average gain is about 3.6 dBi. There is a slot on the patch which is loaded by two varactor diodes to form a tunable notch band. The antenna operates from 2.4 GHz to 12 GHz. The proposed antenna is a good candidate for medical purpose since it has a sufficient amount of gain and bandwidth. We used active circuit to increase the flexibility of setting rejection band to prevent having interference from other sources such as Wi-Fi. The antenna is fabricated and there is a good agreement between the simulation and measurement results. |
| Author(s): | A. Darvazehban, T. Rezaee |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 3 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1815 KB |
| Title: | Electro-Magnetic Simulation in Design of High Sensitivity NMR Probes using High-Temperature-Superconductors |
| File Type: | Conference Paper |
| Issue: | Volume: Student Paper Competition Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 403 KB |
| Title: | Electro-Magnetic Simulation in Design of High Sensitivity NMR Probes using High-Temperature-Superconductors |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic-Simulation-Driven-Design: Modeling and Optimization Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 403 KB |
| Title: | Two-Step Reduction Approach based on the Scattering-Symmetric Lanczos Algorithm for TLM-ROM |
| File Type: | Conference Paper |
| Issue: | Volume: Fast and Efficient CEM Methods Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 163 KB |
| Title: | Trajectory Tracking of Rotating Shaft with Active Magnetic Bearings under Different Reference Signals |
| Abstract: | Using magnetic levitation technology to implement a reference signal can avoid fluid mechanical surge and better control the movement of motorized spindle-mounted cutting tools. Magnetic levitation has the advantages of no friction, no mechanical wear, and high efficiency. In this paper, the performance of axial trajectory tracking control of active magnetic bearings with a classical proportional-integral-derivative (PID) controller is studied. First, the principles of trajectory tracking with an active magnetic bearing system are expounded, and the mechatronics models of such a system are established. Then, a PID controller is designed and trajectory tracking performance using different reference signals is verified by simulation and experiment. The results show that PID-based control of magnetic bearings can meet the requirements of tracking position control. In the experiments, the tracking errors were all within 18 μm in the rotating state. |
| Author(s): | X. Guan, J. Zhou, H. Wu, Y. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 9 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2600 KB |
| Title: | Time-Domain Simulation of Chaotic Dynamics in Nonlinear Frequency-Dependent Dielectric Materials |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Advances in Time Domain Modeling Techniques Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 119 KB |
| Title: | Time-Domain Magnetic Shielding of a Thin Conducting Screen Against a Small Loop |
| File Type: | Conference Paper |
| Issue: | Volume: S22 Advances on Time Domain Modeling and Design I Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 924 KB |
| Title: | Time-Domain Magnetic Shielding Effectiveness of Planar Stratified Shields |
| File Type: | Conference Paper |
| Issue: | Volume: S25 Time Domain Methods II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 221 KB |
| Title: | The Interaction Forces in Magnetic Support Systems of Vertical Type |
| Abstract: | In this article, the vertical and horizontal forces of the interaction of permanent magnets in a Magnetic Suspension (support) System of Vertical Type (MSVT) are considered. The magnetic support system contains multi-row magnetic bands (strips), which have alternating polarity. The magnetization vector, M, is directed horizontally, as opposed to classical support systems where M is directed vertically. The results of the comparison of the vertical and lateral forces for the classic Magnetic System of Horizontal Type (MSHT) and the MSVT are presented too. An effectiveness factor, mu eff = fz/mg, is adopted (where fz is the vertical force per unit length of magnetic band and mg is its weight) and is used as the principle criterion for comparison. In this paper it is shown that when the vertical displacement of the moving part of the support system of MSVT causes the vertical force, fz, to reach its maximum, the lateral force fy is at its minimum. |
| Author(s): | E. Frishman |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 4 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1376 KB |
| Title: | The Adaptive Wind Driven Optimization and its Application in Electromagnetics |
| File Type: | Conference Paper |
| Issue: | Volume: S04 Antenna Optimization for RFID Applications Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 608 KB |
| Title: | Surface Impedance Boundary Conditions of High Order of Approximation for the Finite Integration Technique |
| Abstract: | Time domain Surface Impedance Boundary Conditions (SIBCs) of high order of approximation relating the electric field integral along the edge of the computational cell and the magnetic flux through its facet are derived and implemented into the Finite Integration Technique (FIT). It enables such effects as curvature of the conductor surface and variation of the electromagnetic field along the interface to be accurately described in the formulation. As a result, accuracy of numerical results is improved and the application area is expanded as compared with formulations employing classical low order Leontovich SIBCs. Numerical results obtained using low- and highorder FIT-SIBC formulations are compared with analytical results to demonstrate the advantages of the proposed approach. |
| Author(s): | Luca Di Rienzo, Nathan Ida, Sergey Yuferev, Luca Di Rienzo, Nathan Ida, Sergey Yuferev |
| File Type: | Journal Paper |
| Issue: | Volume: 22 Number: 1 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 265 KB |
| Title: | Surface Impedance Boundary Conditions of High Order of Approximation for the Finite Integration Technique |
| File Type: | Conference Paper |
| Issue: | Volume: Poster Session Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 110 KB |
| Title: | Spatio-Temporally Modulated Metamaterials |
| File Type: | Conference Paper |
| Issue: | Volume: S33 Complex Meta-Structures and Applications - II Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 158 KB |
| Title: | Source Enumeration Method Combining Gerschgorin Circle Transform and Generalized Bayesian Information Criterion in Large-scale Antenna Array |
| Abstract: | A new source enumeration method based on gerschgorin circle transform and generalized Bayesian information criterion is devised, for the case that the antenna array observed signals are overlapped with spatial colored noise, and the number of antennas compared with that of snapshots meet the requirement of general asymptotic regime. Firstly, the sample covariance matrix of the observed signals is calculated, and then gerschgorin circle transformation is carried out on the sample covariance matrix. With the help of the more obvious distinction between the transformed signal gerschgorin circle radius and the noise gerschgorin circle radius, the observation statistic used to establish the likelihood function of the information theoretic criterion is constructed, by using the estimated values of the transformed sample covariance matrix’s eigenvalues, and according to the idea of corrected Rao’s score test, the observed statistics used to establish the likelihood function of the ITC are constructed. Based on the statistics, the source number is estimated by employing the generalized Bayesian information criterion (GBIC). The effectiveness of the proposed method is validated by experiments. Compared with the information theoretic criterion (ITC) methods and gerschgorin circle method (GDE), in Gaussian white noise, at the time M/N ≥ 1, that is the relationship between the number of antennas and that of snapshots meets the requirement of the general asymptotic regime, the proposed method can accurately estimate the source number with 100% probability, the other methods failed. Compared with the ITC methods based on eigenvalue diagonal loading and GDE, in colored noise, at the time M/N ≥ 1, the proposed method can accurately estimate the source number with 100% probability, the other methods failed. Compared with the methods based on random matrix theory, in colored noise, the proposed method can estimate the source number with 100% probability, but the estimation of other methods failed. The proposed method has wide applicability, in terms of the relationship between the numbers of antennas and snapshots, it is suitable for both general asymptotic regime and classical asymptotic system, and in terms of noise characteristics, it is suitable for both Gaussian white noise environment and colored noise environment. |
| Author(s): | C. Wang, Y. Zeng, L. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 7 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1586 KB |
| Title: | Size Reduction and Harmonic Suppression of Parallel Coupled-Line Bandpass Filters Using Defected Ground Structure |
| Abstract: | A novel miniaturized parallel coupledline bandpass filter with suppression of second, third and fourth harmonic frequencies, is demonstrated in this paper. The new filter is based on the slow-wave effect of the Defected Ground Structure (DGS) to achieve size minimization, while the spurious responses are eliminated by the band-rejection property of the DGS unit. These features offer the classical parallel coupled-line bandpass filter simultaneous compactness and wide stopband performance. Using the proposed DGS unit, does not require the filter parameters to be recalculated and, this way, the classical design methodology for microstrip parallel coupled-line filters can still be used. As an example, a 2.0 GHz parallel coupledline filter has been designed and measured in order to show the validity of the proposed DGS. Compared with the conventional parallel coupledline bandpass filters, the second, third and fourth measured spurious responses are suppressed to - 45, -43 and -34 dB, respectively. In addition, the size of the prototype filter is reduced by 20% compared to that of the conventional parallel coupled-line filter. |
| Author(s): | F. Karshenas, A. R. Mallahzadeh, J. Rashed-Mohassel |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 2 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 346 KB |
| Title: | Research on EBE-FEM Parallel Algorithm Combined with Fast Color Marking Method Based on CUDA Platform |
| Abstract: | The element-by-element finite element method (EBE-FEM) parallel algorithm has been realized on Compute Unified Device Architecture (CUDA) platform in this paper. An improved fast color marking method (FCM) combined with tabu search algorithm is proposed to solve the problem that the elements sharing a node wait for accessing the same memory space in parallel computation. The elements in the same color can be processed at the same time without waiting. This method can get more even color grouping faster than the classical coloring method (CCM). Combining it with the EBE parallel algorithm can achieve faster element-level operations. The validity and accuracy of the method has been verified by comparing the computed results with the analytical solution of the magnetic field produced by the solenoid. The parallel program is applied to analyze the main magnetic field of a single-phase transformer, which shows higher speedup performance. |
| Author(s): | X. Ren, X. Yan, J. Lan, Z. Ren, Y. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 10 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1024 KB |
| Title: | Reduction of Mutual Coupling for Broadband Vivaldi Antennas Using Characteristic Modes Analysis and Lumped Loads |
| Abstract: | A method to reduce mutual coupling for broadband Vivaldi antennas is presented in this paper. Theory of characteristic modes is used to analyze the surface currents on the Vivaldi antennas which may contribute to mutual coupling, and inductive loads are used to suppress these modes. Mutual coupling between adjacent Vivaldi antennas is reduced by 10~20 dB on average in a wide bandwidth. Three configurations, including the classical design, design with slot, and design with inductive loads are studied. Numerical and experimental results are presented to verify the effectiveness of this method, which ensures that the method has very little influence to normal operation of Vivaldi antennas. |
| Author(s): | Z. Ma, Q. Wu |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 6 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1675 KB |
| Title: | Reduced Order Modeling in TLM |
| File Type: | Conference Paper |
| Issue: | Volume: Hybrid and Coupled Time Domain Solution Methods Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 172 KB |
| Title: | Rational Approximation of Noisy Frequency Responses |
| File Type: | Conference Paper |
| Issue: | Volume: Macromodeling for EMC and SI Complex Systems Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 114 KB |
| Title: | Radiated EM Flux based Diagnostic Approach for Stator Insulation Failures in Inverter fed Motors |
| File Type: | Conference Paper |
| Issue: | Volume: S12 Student Paper Competition II Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 526 KB |
| Title: | Radiated EM Flux based Diagnostic Approach for Stator Insulation Failures in Inverter fed Motors |
| File Type: | Conference Paper |
| Issue: | Volume: S27 Low Frequency Magnetics Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 526 KB |
| Title: | Quantum Algorithms for the Solution of Matrix Equations in Electromagnetics |
| File Type: | Conference Paper |
| Issue: | Volume: S25 Microwave Quantum Information Technology - II Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 219 KB |
| Title: | Probe Position Errors Corrected Near-Field – Far-Field Transformation with Spherical Scanning |
| Abstract: | Two effective approaches to correct known positioning errors in a near-field – far-field (NF–FF) transformation with spherical scan for electrically long antennas are proposed and validated numerically and experimentally. They rely on a nonredundant sampling representation of the voltage acquired by the probe, obtained by assuming that the antenna under test is enclosed in a cylinder ended in two half-spheres. The former approach exploits the singular value decomposition method, to retrieve the NF data at the points fixed by the sampling representation from the acquired irregularly spaced ones, and can be used when the nonuniformly spaced samples lie on nonuniform parallels. The latter employs an iterative technique, which can be adopted even if such a hypothesis is not satisfied, but requires the existence of a one-to-one correspondence associating at each uniform sampling point, the nearest nonuniform one. Once the uniform samples have been recovered, the NF data needed by the classical spherical NF–FF transformation are efficiently evaluated via an optimal sampling interpolation algorithm. |
| Author(s): | F. D. Agostino, F. Ferrara, C. Gennarelli, R. Guerriero, M. Migliozzi |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 2 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2128 KB |
| Title: | Post Processing Techniques in Far Field Antenna Measurement Ranges |
| File Type: | Conference Paper |
| Issue: | Volume: Antenna Measurement Post Processing Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 2202 KB |
| Title: | Perspective of the Uniaxial Wavelet-transformed FDTD Scheme |
| File Type: | Conference Paper |
| Issue: | Volume: Student Paper Competition Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 0 KB |
| Title: | Perspective of the Uniaxial Wavelet-transformed FDTD Scheme |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Computational Techniques in Electromagnetics - 1 Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 644 KB |
| Title: | Performance Considerations for Quantum Radar |
| File Type: | Conference Paper |
| Issue: | Volume: S25 Microwave Quantum Information Technology - II Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 1231 KB |
| Title: | Passive Guaranteed Broadband Equivalent Circuit Derivation of Symmetrical Multi-port Systems: Application to Multi-conductors and RF-Inductors |
| File Type: | Conference Paper |
| Issue: | Volume: Time Domain Methods in Numerical Electromagnetics Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 299 KB |
| Title: | Parallel Realization of Element by Element Analysis of Eddy Current Field Based on Graphic Processing Unit |
| Abstract: | The element by element parallel finite element method (EbE-PFEM) applied to engineering eddy current problem is presented in this paper. Unlike classical finite element method (FEM), only element matrix is needed to store for EbE method. Thereby more storage memory saved. Element by element conjugated gradient (EbE-CG) method is used to solve the equations which are discretized from elements level. Considering the ill-conditioned character of system equations, highly parallel Jacobi preconditioned (JP) method is used to accelerate the convergence. Besides, the process of dealing with boundary condition based on EbE theory is introduced. To validate the method, a 2D eddy current problem in complex frequency domain is used. The numerical analysis is carried out on the graphic processing units (GPU) with a compute unified device architecture (CUDA) parallel programming model to accelerate the convergence. And the results demonstrate that the JP method and GPU platform are effective in solving eddy current field with improved convergence. |
| Author(s): | D. Wu, X. Yan, R. Tang, D. Xie, Z. Ren |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1590 KB |
| Title: | Parallel Realization of Element by Element Analysis of Eddy Current Field Based on Graphic Processing Unit |
| Abstract: | The element by element parallel finite element method (EbE-PFEM) applied to engineering eddy current problem is presented in this paper. Unlike classical finite element method (FEM), only element matrix is needed to store for EbE method. Thereby more storage memory saved. Element by element conjugated gradient (EbE-CG) method is used to solve the equations which are discretized from elements level. Considering the ill-conditioned character of system equations, highly parallel Jacobi preconditioned (JP) method is used to accelerate the convergence. Besides, the process of dealing with boundary condition based on EbE theory is introduced. To validate the method, a 2D eddy current problem in complex frequency domain is used. The numerical analysis is carried out on the graphic processing units (GPU) with a compute unified device architecture (CUDA) parallel programming model to accelerate the convergence. And the results demonstrate that the JP method and GPU platform are effective in solving eddy current field with improved convergence. |
| Author(s): | D. Wu, X. Yan, R. Tang, D. Xie, Z. Ren |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1590 KB |
| Title: | Parallel Realization of Element by Element Analysis of Eddy Current Field Based on Graphic Processing Unit |
| Abstract: | The element by element parallel finite element method (EbE-PFEM) applied to engineering eddy current problem is presented in this paper. Unlike classical finite element method (FEM), only element matrix is needed to store for EbE method. Thereby more storage memory saved. Element by element conjugated gradient (EbE-CG) method is used to solve the equations which are discretized from elements level. Considering the ill-conditioned character of system equations, highly parallel Jacobi preconditioned (JP) method is used to accelerate the convergence. Besides, the process of dealing with boundary condition based on EbE theory is introduced. To validate the method, a 2D eddy current problem in complex frequency domain is used. The numerical analysis is carried out on the graphic processing units (GPU) with a compute unified device architecture (CUDA) parallel programming model to accelerate the convergence. And the results demonstrate that the JP method and GPU platform are effective in solving eddy current field with improved convergence. |
| Author(s): | D. Wu, X. Yan, R. Tang, D. Xie, Z. Ren |
| File Type: | Express Journal Paper |
| Issue: | Volume: 1 Number: 4 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1607 KB |
| Title: | On the Convergence Properties of the Multiple Sweep Method of Moments |
| Abstract: | This paper investigates the convergence properties of the Multiple Sweep Method of Moments (MSMM), both analytically and numerically, and presents some numerical results for various 2D scattering geometries, such as a strip, a cylinder, and a rough surface with and without a target on it. The MSMM is an O(N2) iterative method for solving the large matrix equations which arise in the method of moments (MM) analysis of electrically large bodies. In the MSMM, the body is split into P sections and the currents on these sections are found in a recursive fashion. Although the MSMM is a frequency domain solution, it has a time domain interpretation. The first sweep includes the dominant scattering mechanisms and each subsequent sweep includes higher order mechanisms. A connection between the MSMM and classical iterative methods is established in this paper. Under certain conditions, the MSMM is shown to be mathematically equivalent to a block Jacobi preconditioned system of equations that results from the moment method, and solved via the method of symmetric successive over-relaxation (SSOR) with relaxation factor ! = 1. Based on this connection, the convergence is analyzed by examining the eigenvalue distribution of the iteration matrix for different classes of 2D geometries, and for electric and magnetic field integral equation formulations and TEz and TMz polarizations. In addition, the MSMM is compared with other recently used iterative methods for rough surface scattering problems, namely the Method of Ordered Multiple Interactions (MOMI), or the Forward-Backward (FB) Method. The results show that the MSMM converges for some problems for which the MOMI (and FB) fails to converge, e.g., the rough surface with a target on it, or when the surface becomes multi-valued which causes large offdiagonal elements in the interaction matrix. |
| Author(s): | D. Colak, R. J. Burkholder , E. H. Newman, D. Colak, R. J. Burkholder , E. H. Newman |
| File Type: | Journal Paper |
| Issue: | Volume: 22 Number: 2 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 340 KB |
| Title: | On the Conforming Combination of the Electric and Magnetic Field Integral Equations |
| File Type: | Conference Paper |
| Issue: | Volume: S06 Student Paper Competition I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 266 KB |
| Title: | On the Conforming Combination of the Electric and Magnetic Field Integral Equations |
| File Type: | Conference Paper |
| Issue: | Volume: S47 Integral Equation Solvers for Real-Life Applications I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 266 KB |
| Title: | On Recent Machine Learning Algorithms for Brain Activity Interpretation |
| File Type: | Conference Paper |
| Issue: | Volume: Imaging, Computation and Inverse Methods in Biomedicine Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 161 KB |
| Title: | OBTAINING SCATTERING SOLUTIONS FOR PERTURBED GEOMETRIES AND MATERIALS FROM MOMENT METHOD SOLUTIONS |
| Abstract: | In this paper, we present an efficient method for computing the solution to scattering problems using a perturbation scheme based on the solution of related original problems. Assuming the radar cross section has been computed for a particular scatterer associated with a moment method matrix B, we call the computation of the radar cross section of a slightly perturbed scatterer a "perturbed problem of B". If the original problem has n unknowns, and the perturbed problem is formed by changing p cells of the original problem, then our method requires an operation count of O(n2p + p3) while a direct moment method solutions requires an operation count of O(n3). Our method involves application of the Sherman-Morrison-Woodbury formula for inverses of perturbed matrices. We show that the method can be easily implemented in any moment method code, and the user does not have to learn a new input procedure. Further, the modified code can provide a basis for a non-linear optimization procedure which minimizes the radar cross section of an obstacle by varying the surface impedance's. An appropriate objective function in this problem depends on the radar cross section at the angles and frequencies of interest. Let n be the number of cells in the obstacle and let p be the number of cells with variable impedance, with n>>p. Then application of the Sherman-Morrison-Woodbury formula results in objective function evaluations requiring an O(np+p3) operation count. In contrast, application of the classical moment method results in objective function evaluations requiring an O(n3) operation count. Numerical results from large practical problems demonstrate the efficiency and stability of the new method. [Vol. 3, No. 2, pp. 95-118 (1988)] |
| Author(s): | Ellzabeth Yip, Brian Tomas, Ellzabeth Yip, Brian Tomas |
| File Type: | Journal Paper |
| Issue: | Volume: 3 Number: 2 Year: 1988 |
| Download Link: | Click here to download PDF File Size: 1321 KB |
| Title: | Observations on Adaptive Refinement Using the Locally-corrected Nystrom Method |
| File Type: | Conference Paper |
| Issue: | Volume: S21 Nystrom Methods for Electromagnetics Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 169 KB |
| Title: | Numerical Study of a Family of IMEX-DGTD Methods for the 3D Time-Domain Maxwell’s Equations |
| File Type: | Conference Paper |
| Issue: | Volume: S22 Computational Electromagnetics Advanced Algorithms and Emerging Applications II Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 445 KB |
| Title: | Numerical Solution of Electromagnetic Integral Equations by the Meshfree Collocation Method |
| Abstract: | This paper presents guidelines for mesh free numerical solution of electromagnetic integral equations. Both static and dynamic problems are considered, including the EFIE and the MPIE for dynamic case. Different choices of the kind of meshfree method, shape functions and their parameters are studied and proper choices are suggested by logical deduction, experience or previous reports. The final configuration is applied to classical problems in one and two dimensions such as electric charge (density) and electric current (density) distributions over a line and flat plates, respectively. The method is validated by convergence analysis and is compared with MoM. In addition, suggestions are made for bypassing numerical integrations that make the construction of the coefficient matrix integration free. |
| Author(s): | B. Honarbakhsh, A. Tavakoli |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 9 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 1208 KB |
| Title: | Nonlocal Hydrodynamic Models for the Optical Response of Plasmonic Nanostructures |
| File Type: | Conference Paper |
| Issue: | Volume: S02 Modeling and Applications - I Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 314 KB |
| Title: | Nonlocal Hydrodynamic Models for the Optical Response of Plasmonic Nanostructures |
| Abstract: | In order to model the interaction between light and plasmonic structures at deep-nanometer scale, which is governed by non-classical effects, a nonlocal hydrodynamic approach has been extensively studied. Several hydrodynamic models have been proposed, solving the coupled equations: the linearized hydrodynamic equation of motion and the electrodynamic Maxwell’s equations, by employing additional boundary conditions. This work compares four hydrodynamic models: the hard wall hydrodynamic model (HW-HDM), the curl-free hydrodynamic model (CF-HDM), the shear forces hydrodynamic model (SF-HDM), and the quantum hydrodynamic model (Q-HDM). The analysis is conducted for a metallic spherical nanoparticle, as an example. The above hydrodynamic models are also compared with experiments available in literature. It is demonstrated that HW-HDM and QHDM outperform the other two hydrodynamic models. |
| Author(s): | M. Kupresak, X. Zheng, G. A. E. Vandenbosch, V. V. Moshchalkov |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1300 KB |
| Title: | Near to Far-Field Plane-Polar Transformation from Probe Positioning Error Affected Data |
| Abstract: | In this article, two efficient approaches for the correction of known positioning errors of the measurement probe in a plane-polar near to far-field (NTFF) transformation, requiring a minimum number of NF data in the case of quasi-planar antennas, are presented and experimentally assessed. Such a NTFF transformation benefits from a non-redundant sampling representation of the voltage detected by the probe got by modeling an antenna with a quasi-planar geometry through a double bowl, a surface consisting of two circular bowls with the same aperture radius, but with lateral bends which may differ to better fit the antenna shape. The uniform samples, i.e., those at the points set by the representation, are accurately retrieved from the collected not regularly distributed ones either by applying a singular value decomposition based approach or an iterative scheme. Then, the input NF data necessary for the classical plane-rectangular NTFF transformation are evaluated from the so retrieved non-redundant uniform samples through a 2-D optimal sampling interpolation formula. |
| Author(s): | F. D’Agostino, F. Ferrara, C. Gennarelli, R. Guerriero, M. Migliozzi |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 4 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 3201 KB |
| Title: | Nanoscopy with grating-assisted optical diffraction tomography |
| File Type: | Conference Paper |
| Issue: | Volume: Efficient Numerical Solutions of Large Multi-dimensional Inverse Scattering Problems Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 632 KB |
| Title: | Nanoplasmonics FDTD Simulations Using a Generalized Dispersive Material Model |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in FDTD Method and Applications Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 1289 KB |
| Title: | Multi-Resolution Analysis of Mortar Diffusion Back-Scattered Signal in Civil Buildings |
| File Type: | Conference Paper |
| Issue: | Volume: Computational Methods for Nondestructive Evaluation and Materials Characterization Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 241 KB |
| Title: | Multi-Fidelity Optimization of Microwave Structures with FEKO Using Response Surface Approximation and Space Mapping |
| File Type: | Conference Paper |
| Issue: | Volume: FEKO Modeling and Analysis IV Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 181 KB |
| Title: | Multi-Fidelity Optimization of Microwave Structures Using Response Surface Approximation and Space Mapping |
| Abstract: | A computationally efficient method for design optimization of CPU-intensive microwave structures is discussed. The presented technique exploits a response surface approximation surrogate model set up using data from the coarse-mesh EMbased model being a relaxed-accuracy representation of the microwave structure in question. The surrogate model is further subjected to the classical space mapping optimization. It is demonstrated that the new technique is able to provide a satisfactory design with a few electromagnetic simulations of the original structure. Because of using functional approximation, no circuit equivalent coarse model is necessary, which makes the presented approach particularly suitable for structures for which the development of the reliable coarse model is problematic (e.g., antennas). |
| Author(s): | S. Koziel |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 6 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 639 KB |
| Title: | MODELISATION OF PROBE FEED EXCITATION USING ITERATIVE METHOD |
| Abstract: | This paper presents an implementation of an iterative method based on the waves concept for analyzing patch antennas fed by coaxial probes. This method includes a two-dimensional fast Fourier transform (FFT-2D) in a wave guide environment. The method has the advantage of simplicity in that it does not involve basis functions and inversion of matrices, as used in other calculation methods. Therefore, it is capable of analyzing larger bodies than other classical techniques. An implementation of the iterative calculation is shown for the extraction of S parameters of microwave components and antennas. The good agreement between simulation results and experimental published data justifies the design procedure and validates the present analysis approach. |
| Author(s): | H. Zairi, A. Gharsallah, A. Gharbi, H. Baudrand, H. Zairi, A. Gharsallah, A. Gharbi, H. Baudrand |
| File Type: | Journal Paper |
| Issue: | Volume: 19 Number: 3 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 416 KB |
| Title: | Modeling of metamaterials with classical homogenization principles |
| File Type: | Conference Paper |
| Issue: | Volume: Bianisotropic and Metamaterial Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 53 KB |
| Title: | Inverse Design of Engineered Materials for Extreme Optical Devices |
| File Type: | Conference Paper |
| Issue: | Volume: S43 Computational Nanophotonics: Advanced Numerical Methods and Applications I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 374 KB |
| Title: | Including Substrate Losses and Noise in a Quantum Mechanical Model of a Josephson Traveling-Wave Parametric Amplifier |
| File Type: | Conference Paper |
| Issue: | Volume: S22 Microwave Quantum Information Technology - I Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 229 KB |
| Title: | Implications of Galilean Electromagnetism in Numerical Modeling |
| Abstract: | The purpose of this article is to present a wider frame to treat the quasi-static limit of Maxwell’s equations. We discuss the fact that there exists not one but indeed two dual Galilean limits, the electric and the magnetic one. We start by a re-examination of the gauge conditions and their compatibility with Lorentz and Galilean covariance. By means of a dimensional analysis on fields and potentials we first emphasize the correct scaling yielding the equations in the two limits. With this particular point of view, the gauge conditions of classical electromagnetism are continuity equations whose range of validity depend on the relativistic or Galilean nature of the underlying phenomenon and have little to do with mathematical closure assumptions taken without physical motivations. We then present the analysis of the quasi-static models in terms of characteristic times and visualize their domains of validity in a suitable diagram. We conclude by few words on the Galilean electrodynamics for moving media, underlying the transformation laws for fields and potentials which are valid in the different limits. |
| Author(s): | F. Rapetti, G. Rousseaux |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 9 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 868 KB |
| Title: | Impact of Composite Materials on the Shielding Effectiveness of Enclosures |
| Abstract: | This paper investigates and compares the electromagnetic behavior of different shielding enclosures built with composite panels (dielectric materials with conducting inclusions, carbon-fiber, fiberglass, conductive materials). The numerical model is based on a full wave finite element method taking into account the geometrical details of the walls and avoiding the use of the classical equivalent layer approach. A 2D composite enclosure with two wall structures is modeled: fiber rods shielding and metal screen shielding. Impacts of conductivity and rod diameter on the shielding effect are investigated. Concerning metal screen, the shielding effectiveness is studied for different metals with the same mass, leading to identify the most effective metal. The influence of the angle of incidence and the number of apertures is also studied. Finally, a comparison is performed considering the same mass of the two composite wall structures, each composed of fiberglass and carbon fiber. |
| Author(s): | W. Abdelli, X. Mininger, L. Pichon, H. Trabelsi |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 1123 KB |
| Title: | Highly Efficient Technique for the Full-Wave Analysis of Circular Waveguide Filters Including Off-Centered Irises |
| Abstract: | A rigorous method for the full-wave analysis and design of waveguide filters implemented in circular waveguide technology, and including offcentered circular irises, is presented. The implemented tool is based on an integral equation technique, which provides a full-wave representation of the elementary blocks of the analyzed components in terms of generalized impedance matrices. With the aim of improving the efficiency of the developed tool, the radial variation of the modal solutions of the circular waveguides has been expressed in terms of sinusoidal functions, thus avoiding the use of the more cumbersome Bessel’s functions employed in the classical formulation. Furthermore, line integrals have been used (instead of surface integrals) to compute the modal coupling coefficients of the planar waveguide junctions involved in the considered filters, thus drastically reducing the CPU effort related to the implemented tool. New designs concerning band-pass filters including off-centered circular irises are also provided. The obtained results show that the relative position of the considered circular irises can be considered as a new design parameter with a noteworthy influence on the electrical response of the investigated components. The accuracy of the proposed method has been successfully validated by comparing the obtained results with data extracted from both the technical literature and a commercial software based on the finite-element method. |
| Author(s): | A. A. San-Blas, J. M. Roca |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 11 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1074 KB |
| Title: | High Precision Method to Solve the Maxwell's Equations in the Time Domain Adapted to Structured Meshes |
| File Type: | Conference Paper |
| Issue: | Volume: Higher Order CEM: Development and Applications Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 349 KB |
| Title: | Generalization of the Vector Hysteron Model through the Dependence of Moving Functions on Frequency |
| File Type: | Conference Paper |
| Issue: | Volume: S38 Low-Frequency Electromagnetic Inverse Problems I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 72 KB |
| Title: | Full-Wave Modeling of the Emission of a Microwave Frequency Single Photon Source |
| File Type: | Conference Paper |
| Issue: | Volume: S22 Microwave Quantum Information Technology - I Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 473 KB |
| Title: | Fractal Interpolation Function based Thin Wire Antennas |
| Abstract: | This paper presents an approach for the design of wire antennas based on fractal interpolation functions (FIFs). The interpolation points and the contraction factors of the FIFs are chosen as free parameters to modify the antenna geometry. The proposed structures’ gain and radiation pattern can be optimized using FIF parameters. Producible prefractal antennas obtained in the intermediate iterations of fractal generation have compact sizes compared to classical counterparts. The error in prefractal geometry and the original fractal is bounded, and can be determined in terms of the finest producible detail’s dimensions. The emerging structures have multiband behavior due to their self-similar and symmetric nature. To illustrate the approach, we have provided finite element based simulations for several prefractal antennas. |S11|, the gain, the radiation efficiency, the radiation patterns, and feed point impedances for the demonstrated antennas are calculated numerically. The results indicate that produced antennas can be used in applications that require limited mechanical size, multiple operating bands, and controlled radiation patterns. |
| Author(s): | G. Kalender, E. Y. Zoral, S. Gunel |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 11 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 7463 KB |
| Title: | FPGA Accelerated Ant Colony Optimization for Phased Array Design |
| File Type: | Conference Paper |
| Issue: | Volume: Parallelized Computing for Accelerated EM Applications Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 434 KB |
| Title: | Fast Design Optimization of Microwave Structures Using Co-Simulation-Based Tuning Space Mapping |
| Abstract: | Tuning space mapping (TSM) expedites efficient design optimization of microwave circuits by replacing sections in the electromagnetic (EM) model with corresponding sections of designable equivalent elements. A key assumption of TSM is that these designable elements can replace their respective EM model sections without introducing significant distortion in the structure’s response. This can be achieved through the co-calibrated ports technique introduced in Sonnet em. Here, we generalize the TSM algorithm. A tuning model is constructed by simulating the EM model sections separately and connecting them with the tuning components through a co-simulation process. This allows us to implement the TSM algorithm with any EM simulator. The response misalignment between the original structure and the tuning model is reduced using classical space mapping. The proposed algorithm is illustrated through the design of two microstrip filters simulated in FEKO. |
| Author(s): | S. Koziel, J. W. Bandler |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 8 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 704 KB |
| Title: | Electromagnetic Point Source Reconstruction by Reversed-TLM Method |
| Abstract: | Classical methods for source synthesis are iterative, time consuming, and not always adapted to the desired problem. In this paper, we present a new method of electromagnetic source synthesis based on the time-reversal technique. This approach employs the reversed-TLM method and permits the reconstruction of a source distribution, from its electromagnetic far-field radiation. Point-like source reconstruction results show that by using this method, the “classical” half-wavelength resolution limit is overcome. |
| Author(s): | A. Ungureanu, T. Vuong, F. Ndagijimana |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 9 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 1170 KB |
| Title: | Electromagnetic Field Shielding of a Spherical Shell – Revisited |
| Abstract: | This paper takes a fresh look at two classical EM shielding problems involving an integral imperfectly conducting spherical shell and a perfectly conducting hollow sphere with an aperture. Previous studies of the EM shielding provided by these objects have concentrated on evaluating the E- and H-fields at the center of the shield, where only one term of the spherical wave function expansion is needed. While the internal H-field in the shielded volume of the conducting shell is very close to being constant, the same is not true for the E-field, where there can be a significant variation in the E-field intensity from point to point within the interior. For both of these canonical shielding problems, the method of analysis is described and then applied to determine cumulative probability distributions for the internal fields. In Part 1 of this paper, the frequency-dependent analysis for the case of the complete shell is discussed. To avoid certain numerical overflow problems in evaluating the spherical harmonic solution for lossy media, the use of scaled Hankel functions is described. Additionally, closedform expressions for the wave expansion coefficients in the spherical coordinate system are derived. In Part 2 of this paper, the treatment of the hollow sphere with an aperture is obtained using a quasi-static model that also permits the determination of the E-fields anywhere in and around the sphere. |
| Author(s): | |
| File Type: | Newsletter Paper |
| Issue: | Volume: 23 Number: 2 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 3150 KB |
| Title: | Eddy Currents Induced in Two Parallel Round Conductors |
| Abstract: | The paper presents a method of analysis of eddy currents induced in a system of two parallel round conductors by a transverse alternating magnetic field generated by a current in one of them. The magnetic field is represented by means of magnetic vector potential as expansion into Fourier series. Using the Laplace and Helmholtz equations as well as the classical boundary conditions we determine analytically the current density induced due to the proximity effect. Power transmission lines with round conductors are widely used in distribution networks. Therefore, although the paper is theoretical, the determination of electromagnetic parameters of the power transmission lines is of huge practical significance. |
| Author(s): | T. Szczegielniak, P. Jablonski, D. Kusiak, Z. Piatek |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 12 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1790 KB |
| Title: | Direction of Arrival Estimation in a Multipath Environment: an Overview and a New Contribution |
| Abstract: | Abstract — This paper proposes a new computationally efficient algorithm for direction-of-arrival (DOA) estimation in a multipath environment using a uniform linear array (ULA) of equispaced sensors. The paper starts by presenting a comprehensive overview of the classical MUSIC algorithm used for DOA estimation of uncorrelated signals. The effect of different factors related to the signal environment as well as the sensor array is investigated. The concept of spatial smoothing required in the case of correlated signals encountered in multipath propagation environments is then discussed. This then leads to the development of a new computationally efficient DOA estimation algorithm that is proposed for a multipath environment with unknown correlated signals. The algorithm comprises two stages: a first stage for discriminating uncorrelated signals, and a second stage for resolving the directions of arrival of correlated signals using covariance differencing and iterative spatial smoothing. Simulation results show that the proposed algorithm operates at a much lower computational cost compared to standard methods. The proposed algorithm also offers a hardware saving by reducing the number of sensors required to detect a given number of signals. |
| Author(s): | Ebrahim M. Al-Ardi, Raed M. Shubair, Mohammed E. Al-Mualla, Ebrahim M. Al-Ardi, Raed M. Shubair, Mohammed E. Al-Mualla |
| File Type: | Journal Paper |
| Issue: | Volume: 21 Number: 3 Year: 2006 |
| Download Link: | Click here to download PDF File Size: 412 KB |
| Title: | Diakoptic Surface Integral-Equation Formulation Applied to 3-D Scattering Problems |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling by WIPL-D Software Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 582 KB |
| Title: | Diakoptic Surface Integral Equation Formulation Applied to 3-D Electrostatic Problems |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Computational Techniques in Electromagnetics - 2 Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 299 KB |
| Title: | Conformal Antenna Solutions for DMB terminal at S Band |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Electromagnetic Modeling by WIPL-D Software Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 530 KB |
| Title: | Comparison of Nature Based Optimization Methods for Multi-beam Satellite Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: Optimization Techniques for Electromagnetic Applications Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 461 KB |
| Title: | Comparative Study of Analytical and Numerical Techniques in Modeling Electromagnetic Scattering from Single and Double Knife-Edge in 2D Ground Wave Propagation Problems |
| Abstract: | This paper presents a comparative study of some analytical and numerical techniques in the solution of a classical problem of electromagnetic scattering from single and double knife edge above ground. The results of the analytical exact and asymptotic techniques (such as uniform theory of diffraction, parabolic equation diffraction method) are compared with the two-way split-step parabolic equation method (SSPE), through several numerical simulations. Salutary discussions on their capabilities and limitations are presented. Codes used in the simulations are provided in the end. |
| Author(s): | O. Ozgun, L. Sevgi |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 5 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 1785 KB |
| Title: | Co-Simulation Based Tuning Space Mapping with FEKO for Computationally Efficient Optimization of Microwave Structures |
| File Type: | Conference Paper |
| Issue: | Volume: EM Simulations Using FEKO Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 245 KB |
| Title: | Breast Cancer Detection Using Support Vector Machine Technique Applied on Extracted Electromagnetic Waves |
| Abstract: | Breast cancer is one of the most common kinds of cancer, as well as the leading cause of decease among women. Early detection and diagnosis of breast cancer increases the chances for successful treatment and complete recovery for the patient. Mammography is currently the most sensitive method to detect early breast cancer; however, the magnetic resonance imaging (MRI) is the most attractive alternative to mammogram. Manual readings of mammograms may result in misdiagnosis due to human errors caused by visual fatigue. Computer aided detection systems (CAD) serve as a second opinion for radiologists. A new CAD system for the detection of breast cancer in mammograms is proposed. The discrete wavelet transform (DWT), the contourlet transform, and the principal component analysis (PCA) are all used for feature extraction; while the support vector machine (SVM) is used for classification.The system classifies normal and abnormal tissues in addition to benign and malignant tumors. A further investigation was implemented using electromagnetic waves instead of the classical MRI approach. A breast model was generated and near field data of electromagnetic waves were extracted to detect the abnormalities in the breast, especially the masses. |
| Author(s): | M. Al Sharkawy, M. Sharkas, D. Ragab |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 882 KB |
| Title: | Boundary Conditions Simulation in a FDTD/FVTD Hybrid Code |
| File Type: | Conference Paper |
| Issue: | Volume: Time Domain Numerical Modeling Beyond FDTD Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 209 KB |
| Title: | Array Thinning Using Ant Colony Optimization |
| File Type: | Conference Paper |
| Issue: | Volume: Nature-Based Stochastic Optimization Methods Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 289 KB |
| Title: | Application of the Energy-based Stability Condition on the Spatial Wavelettransformed FDTD Scheme |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Computational Techniques in Electromagnetics - 1 Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 111 KB |
| Title: | Antenna Resonant Frequency Modeling based on AdaBoost Gaussian Process Ensemble |
| Abstract: | The design of electromagnetic components generally relies on simulation of full-wave electromagnetic field software exploiting global optimization methods. The main problem of the method is time consuming. Aiming at solving the problem, this study proposes a regression surrogate model based on AdaBoost Gaussian process (GP) ensemble (AGPE). In this method, the GP is used as the weak model, and the AdaBoost algorithm is introduced as the ensemble framework to integrate the weak models, and the strong learner will eventually be used as a surrogate model. Numerical simulation experiment is used to verify the effectiveness of the model, the mean relative error (MRE) of the three classical benchmark functions decreases, respectively, from 0.0585, 0.0528, 0.0241 to 0.0143, 0.0265, 0.0116, and then the method is used to model the resonance frequency of rectangular microstrip antenna (MSA) and coplanar waveguide butterfly MSA. The MRE of test samples based on the APGE are 0.0069, 0.0008 respectively, and the MRE of a single GP are 0.0191, 0.0023 respectively. The results show that, compared with a single GP regression model, the proposed AGPE method works better. In addition, in the modeling experiment of resonant frequency of rectangular MSA, the results obtained by AGPE are compared with those obtained by using neural network (NN). The results show that the proposed method is more effective. |
| Author(s): | T. Zhang, Y. Tian, X. Chen, J. Gao |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 12 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1630 KB |
| Title: | Analysis of Moving Bodies with a Direct Finite Difference Time Domain Method |
| Abstract: | This paper proposes an original and thorough analysis of the behavior of electromagnetic waves in the presence of moving bodies by using the finite difference time domain (FDTD) method. Movements are implemented by changing positions of the objects at each time step, through the classical FDTD time loop. This technique is suitable for non-relativistic speeds, thus for most encountered problems in antennas and propagation domain. The numerical aspects that need to be considered are studied. Then, different bodies in motion are examined: plane wave source with matching resistors, observation point, inclined partially reflecting surface (PRS), line source, and metallic cylinder illuminated by a plane wave. The results are compared with those of special relativity which are considered as the references. Some aspects of special relativity are present in the direct FDTD approach, such as the independence of the velocity of electromagnetic wave propagation with the speed of the source and Lorentz local time (with a different physical interpretation). It is shown that the amplitude of the electric field for a moving plane wave source does not increase with the speed of motion, if the impedance of the source is small. Moreover, for a moving scattering metallic wire, one can observe a phenomenon similar to shock waves. |
| Author(s): | M. Marvasti, H. Boutayeb |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 11 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 21509 KB |
| Title: | Analysis of Dual-Mode Microstrip Patch Filter using Multiscale Wave Concept Iterative Process |
| Abstract: | An iterative method based on the multiscale approach named multiscale wave concept iterative process (MWCIP) is introduced in this paper. This new approach is an extension of the known wave concept iterative process (WCIP). The specificity of the MWCIP method is the nonuniform meshing with macropixels used to improve the time delay computations of the classical iterative procedure. The method is applied successfully to a nondegenerate dual-mode microstrip patch filter. Comparison between the new and classical iterative methods shows that with the presented approach the CPU time and memory requirement have been considerably reduced. |
| Author(s): | T. I. E. Brahim, H. Zairi, A. Gharsallah, A. Gharbi, H. Baudrand |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 9 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 488 KB |
| Title: | Analysis of Broadband Near Zero Index Metamaterials |
| File Type: | Conference Paper |
| Issue: | Volume: 2-2-C Novel Electromagnetic Metamaterials and Their Applications Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 356 KB |
| Title: | Analysis and Design of I-shaped Metamaterial with Notch |
| File Type: | Conference Paper |
| Issue: | Volume: 2-2-C Novel Electromagnetic Metamaterials and Their Applications Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 246 KB |
| Title: | Analysis and Design of a Planar Multilayered FSS with Arbitrary Incidence |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 2 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 209 KB |
| Title: | A Well-Conditioned Approach to Non-Iterative Solution of the Inverse Scattering Problem |
| File Type: | Conference Paper |
| Issue: | Volume: Efficient Solutions to Inverse Electromagnetic Problems Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 474 KB |
| Title: | A Volume Integral Equation Solver for Quantum-Corrected Transient Analysis of Scattering from Plasmonic Nanostructures |
| File Type: | Conference Paper |
| Issue: | Volume: S06 Student Paper Competition I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 265 KB |
| Title: | A Volume Integral Equation Solver for Quantum-Corrected Transient Analysis of Scattering from Plasmonic Nanostructures |
| File Type: | Conference Paper |
| Issue: | Volume: S25 Time Domain Methods II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 260 KB |
| Title: | A Two-Scale AIM for Fast Solution of Volume Integral Equations |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Integral Equation Based Techniques I Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 199 KB |
| Title: | A Stepped Magnetic Suspension System (SMSS) |
| Abstract: | In this article, the vertical and horizontal forces of interaction of permanent magnets in a magnetic support system (magnetic suspension, MS) are considered. Permanent magnets have a stepped structure and uniform magnetization M throughout their entire volume (M = const ). The magnetic support system contains multi-row magnetic strips. The results of the comparison of the vertical and lateral forces for the classic horizontal magnetic system (HMS) are presented too. A stability factor index, the ratio of vertical to lateral force of interaction gamma= fZ/ fY, and an effectiveness factor mu eff=f Z/(mg) are defined (where mg is the weight of the magnets per unit length). A prototype of the proposed magnetic support system was built, and measurements were performed. Analysis of the obtained data indicates that the investigated magnetic suspension system performs better than the classical horizontal MS system. |
| Author(s): | E. Frishman |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 8 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1727 KB |
| Title: | A Robust Algorithm for DOA Estimation of Coherent Sources with UCA |
| Abstract: | Direction of arrival (DOA) estimation of coherent sources with a uniform circular array (UCA) is an intractable problem. The method-of-directionestimation (MODE) algorithm has strong superiority in handling coherent sources compared with the classical MUSIC, and ESPRIT algorithms. However, MODE is sensitive to source numbers and does not work well in the UCA scenario. In order to improve the performance of MODE, a robust DOA estimation method named UCA-PUMA (principal-eigenvector-utilizationfor- modal-analysis) is proposed. The complicated non- Vandermonde structured steering vector of UCA is transformed into a virtual Vandermonde structured steering vector in mode space. The proposed method gives a closed-form solution compared with the original UCAMODE algorithm. The performance of the UCA-PUMA method is evaluated by simulations. Simulation results demonstrate that the UCA-PUMA is more robust to source numbers than the UCA-MODE, and coherent sources can be handled without spatial smoothing. In addition, the UCA-PUMA fully takes advantage of the UCA, which is able to discriminate sources coming from a 360º azimuthal field of view. |
| Author(s): | Y. Tian, Y. Huang, X. Zhang, M. Lin |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 6 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 1620 KB |
| Title: | A New Method for Estimating the Direction-of-Arrival Waves by an Iterative Subspace-Based Method |
| Abstract: | In this paper, a new subspace-based method for high-resolution direction-of-arrival (DOA) estimation of multiple plane waves in a noisy environment is proposed. This method called Iterative-Subspace-Decomposition (ISD) involves an iterative decomposition into two blocks of the matrices corresponding to the noise and the source subspaces. The proposed algorithm provides enhanced estimation performance of the DOA. It also significantly improves the resolution capability with respect to existing algorithms. The method can be applied to low signal-to-noise ratio (SNR) environment and is suitable for arrays with arbitrary sensor geometries, including linear arrays. Several numerical simulations are presented to assess the proposed method enhanced performance in comparison to that obtained by some classical algorithms. This comparative study has shown that the ISD leads to a significant reduction in the Root Mean Square Errors (RMSE) and resolution rate capabilities of the DOA estimates. As though, it is shown that the ISD method is superior in resolving closely spaced signals with a small number of snapshots and at low SNR. |
| Author(s): | H. Changuel, A. Changuel, A. Gharsallah |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 5 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 428 KB |
| Title: | A New Marching-on-in-Time Scheme for Solving the Time-Domain Magnetic Field Integral Equation |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Advances in Integral Equations and Fast Methods Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 1312 KB |
| Title: | A New Integral Equation for the Calculation of the Internal Impedance of a Conductor |
| File Type: | Conference Paper |
| Issue: | Volume: Integral Equation Methods and Applications Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 77 KB |
| Title: | A Hybrid Approach on Metamaterial-Loaded Fractal Antenna Design |
| Abstract: | The paper provides the interoperable hybrid Grasshopper–Grey Wolf optimization (GHGWO) of the Square Split-Ring Resonator (SRR) metamaterial unit cell. This paper discusses the complex phase strategies of the electric and magnetic interplay of the charged microstrip line of the split ring resonator (SRR). Optimized unit of metamaterial cells for their bandwidth enhancement is packed into a new square fractal antenna. In the interim period of dual band efficiency, a new design is introduced for a microstrip line-feeding square fractal antenna with a faulty ground composition. In the second stage, a quasi-static SRR model is being used to streamline its structural parameters in an effort to reinforce the bandwidth so that optimized composition resonates at the required intensity area. In the GHGWO hybrid algorithm, SRR unit cell size limitations should be optimized and the convergence actions of the algorithm improved. Certain evolutions termed modified hybrid BF-PSO classical BFO, chaos PSO and IWO are being tested for efficiency of the Hybrid GHGWO algorithm. In the final stage, optimized SRR unit cells are stacked into a square fractal antenna that provides bandwidth output suited to wireless usages with upper and lower band. The prototype square fractal antenna without and with SRR unit cells is efficiently evaluated by trial results. |
| Author(s): | D. Prabhakar, C. H. Rajendra Babu, V. Adinarayana, V. V. K. D. V. Prasad |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 9 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1527 KB |
| Title: | A Generalized Dispersive Material Model for FVTD Method |
| File Type: | Conference Paper |
| Issue: | Volume: Unstructured Mesh Time Domain Techniques Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 139 KB |
| Title: | Ultra-Wideband Bandpass Filter Based on Parallel-Coupled Microstrip Lines and Defected Ground Structure |
| Abstract: | A compact planar microstrip bandpass filter with 3.1 GHz ? 10.6 GHz bandwidth, below 1 dB in-band insertion loss, 0.2 ns ? 0.6 ns group delay and out-of-band rejection level better than - 10 dB is presented for ultra-wideband (UWB) applications. The desired UWB is realized by etching a defected ground structure (DGS) in the ground plane and loading a folded steppedimpedance stub by one of the coupling microstrip lines. This can offer two transmission zeros at lower and upper edges of the passband, which improve the passband selectivity and out-of-band rejection significantly. An equivalent lumped circuit model is introduced; the result of the circuit model fits the EM model well. The simulated and measured results are in good agreement |
| Author(s): | L. Yang, Y. Hongchun, W. Yawei, X. Shaoqiu |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 1 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 1504 KB |
| Title: | Two-pole Debye Model for Normal Breast Tissue in the Microwave Frequency Range |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling of Biomedical Problems - 1 Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 268 KB |
| Title: | Twenty Three Years: The Acceptance of Maxwell’s Equations |
| Abstract: | Maxwell first published what came to be called “Maxwell’s equations” in 1865. However, it was not until 1888, and Heinrich Hertz’s experimental validation, that Maxwell’s equations were widely accepted as correct. The story of the intervening 23 years is little known. Maxwell, who died in 1879, was exceptionally modest and did not promote his own results at any time. The survival of Maxwell’s equations was up to the only three researchers in the entire world who paid serious attention to Maxwell’s paper in 1865, and his seminal Treatise in 1873: Oliver Heaviside, Oliver Lodge, and George Francis FitzGerald. Later, Hertz joined the group forming “The Four Maxwellians”. In this paper, we describe the torturous 23 year path Maxwell’s equations took from their creation to their initial acceptance. |
| Author(s): | J. C. Rautio |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 1079 KB |
| Title: | Transient Effect of 3D RF-MEMS Structures with Moving Plate |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Modeling Techniques and The Application of Microwave Devices Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 267 KB |
| Title: | Time and Frequency Domain Wave Propagators |
| Abstract: | Is this paper, a new time-domain wave propagator (TDWP) that was recently introduced, is compared against a frequency-domain one that has been in use for more than a decade. The new time-domain wave propagator is built by a two-dimensional (2D) finite-difference time-domain (FDTD) algorithm. The frequency-domain wave propagator is the Split-step Parabolic Equation (SSPE), which is the solution of (one-wave) wave equation in parabolic form. These two techniques can be both used for different kinds of 2D propagation problems. In this paper, ground wave problems, which are difficult to solve, have been taken into consideration in order to compare the methods and show their power. Assuming an azimuthal symmetry, ground wave propagation and surface and/or elevated ducts may be represented via transverse and/or longitudinal refractivity and boundary perturbations in 2D space. The 2D propagation space extends from x=0 (bottom) to x->infinity (top), vertically and from z-> negative infinity (left) to z-> inifity (right) horizontally. Pulse propagation is simulated in TDWP and while a moving window escorts the transmitted waveform from one end to the other end within the FDTD computation space, time histories are accumulated at choses observation points. Any vertical and/or horizontal field profile at a desired frequency is extracted by applying off-line discrete Fourier transformation (DFT). On the other hand, a given field profile is longitudinally ppropagated by moving back and forth between the transverse spatial and wavenumber domains in SSPE. The results of TDWP and SSPE are compared on different ducting and anti-ducting refractivity profiles and their agreement is presented. |
| Author(s): | Funda Akleman, Levent Sevgi, Funda Akleman, Levent Sevgi |
| File Type: | Journal Paper |
| Issue: | Volume: 15 Number: 3 Year: 2000 |
| Download Link: | Click here to download PDF File Size: 7191 KB |
| Title: | Three-Dimensional Spherical-Shaped UPML for FDTD with Cubic Lattices |
| Abstract: | Spherical-shaped uniaxial perfectly matched layer (SS-UPML), an absorbing boundary for threedimensional (3-D) finite-difference time-domain (FDTD) method with cubic cells, is proposed and applied to different objects. This boundary is used for truncating the computational domain to absorb outgoing electromagnetic waves, which has the advantages of higher efficiency and accuracy, compared with the conventional UPML. Update equations are transformed by coordinate rotation to better fit the Cartesian system. Different numerical experiments are implemented to verify the stability and practicability of the proposed boundary in 3-D case. Obtained results illustrate that about a half grid and computational time can be saved after SS-UPML is used, which is the foundation of a wider range of applications. |
| Author(s): | L. Wang, M. Wang, K. Zhang, W. Cui, H. Zheng, E. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 3 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1952 KB |
| Title: | Thinned Interleaved Linear Arrays |
| File Type: | Conference Paper |
| Issue: | Volume: Phased Array and Active Antennas Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 180 KB |
| Title: | The Use of FEKO in Providing High Fidelity Radar Simulation |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Simulation using FEKO Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 65 KB |
| Title: | The Search for an Equivalent Circuit for FIT Simulations using Discrete Ports in a Mutually-coupled Transmit/Receive Antenna Element Pair |
| File Type: | Conference Paper |
| Issue: | Volume: Antenna Modeling Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 228 KB |
| Title: | THE NUMERICAL OF CHARACTERISTICS FOR ELECTROMAGNETICS |
| Abstract: | The objective of this study is to explore the benefits of using the theory of characteristics to develop accurate and efficient numerical algorithms for Computational Electromagnetics. The present work adapts the numerical method of Characterisitics (MOC) from Computational Fluid Dynamics to the one-dimensional Maxwell curl equations in the time domain. The relevant theory of characterisitics is developed and the inverse matching method is used to develop two numerical algorithms based on different interpolation schemes in the initial data surface. Stability and dispersion for these algorithms are discussed. Results are given for one-dimensional model problems involving free space pulse propagation, scattering from perfect conductors and reflection/transmission for lossy dielectric materials. The model problems are designed to provide quantitative insight to both accuracy and efficiency for different classes of realistic application problems. The Finite-Difference Time-Domain (FDTD) method is used as a convenient reference algorithm for comparison. It is demonstrated that these algorithms have accuracy comparable to FDTD, but do not require staggered grid storage, which simplifies impedance boundary conditions and implementation on nonuniform grids. The thoery of characteristics demonstrates a very natural outer boundary condition without nonreflecting approximations or matched layers. A dispersion enhanced version of the MOC is also developed which has phase errors 50-5000 times lower than FDTD. This approach appears promising for development of dispersion enhanced characteristic based schemes for two and three dimensional applications. |
| Author(s): | J.H. Beggs, D.L. Marcum, S-L. Chan, J.H. Beggs, D.L. Marcum, S-L. Chan |
| File Type: | Journal Paper |
| Issue: | Volume: 14 Number: 2 Year: 1999 |
| Download Link: | Click here to download PDF File Size: 962 KB |
| Title: | The Equivalent Circuit Extraction and Application for Arbitrary Shape Graphene Sheet |
| Abstract: | In this work, for the first time the electromagnetic features of graphene are characterized by a circuit model derived instead of fitted from the electric field integral equation (EFIE). The atomically thick graphene is equivalently replaced by an impedance surface. When it is magnetized, the impedance surface is anisotropic with a tensor conductivity. Based on EFIE, the graphene’s circuit model can be derived by the partial element equivalency circuit (PEEC) concept. The anisotropic resistivity is modeled using a serial resistor with current control voltage sources (CCVSs). From the derived circuit model, electromagnetic properties of graphene can be conveniently analyzed. This work also provides a new characterization method for dispersive and anisotropic materials. |
| Author(s): | Y. S. Cao, L. J. Jiang, A. E. Ruehli |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1689 KB |
| Title: | The Equivalent Circuit Extraction and Application for Arbitrary Shape Graphene Sheet |
| Abstract: | In this work, for the first time the electromagnetic features of graphene are characterized by a circuit model derived instead of fitted from the electric field integral equation (EFIE). The atomically thick graphene is equivalently replaced by an impedance surface. When it is magnetized, the impedance surface is anisotropic with a tensor conductivity. Based on EFIE, the graphene’s circuit model can be derived by the partial element equivalency circuit (PEEC) concept. The anisotropic resistivity is modeled using a serial resistor with current control voltage sources (CCVSs). From the derived circuit model, electromagnetic properties of graphene can be conveniently analyzed. This work also provides a new characterization method for dispersive and anisotropic materials. |
| Author(s): | Y. S. Cao, L. J. Jiang, A. E. Ruehli |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1689 KB |
| Title: | The Equivalent Circuit Extraction and Application for Arbitrary Shape Graphene Sheet |
| Abstract: | In this work, for the first time the electromagnetic features of graphene are characterized by a circuit model derived instead of fitted from the electric field integral equation (EFIE). The atomically thick graphene is equivalently replaced by an impedance surface. When it is magnetized, the impedance surface is anisotropic with a tensor conductivity. Based on EFIE, the graphene’s circuit model can be derived by the partial element equivalency circuit (PEEC) concept. The anisotropic resistivity is modeled using a serial resistor with current control voltage sources (CCVSs). From the derived circuit model, electromagnetic properties of graphene can be conveniently analyzed. This work also provides a new characterization method for dispersive and anisotropic materials. |
| Author(s): | Y. S. Cao, L. J. Jiang, A. E. Ruehli |
| File Type: | Express Journal Paper |
| Issue: | Volume: 1 Number: 5 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2272 KB |
| Title: | The Derived Equivalent Circuit Model for Non-magnetized and Magnetized Graphene |
| File Type: | Conference Paper |
| Issue: | Volume: S11 Student Paper Competition I Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 324 KB |
| Title: | The Derived Equivalent Circuit Model for Non-magnetized and Magnetized Graphene |
| File Type: | Conference Paper |
| Issue: | Volume: S15 Integral Equation Methods and Applications II Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 324 KB |
| Title: | The Application of Machine Learning in RCS Calculation for Antenna-Radome System |
| File Type: | Conference Paper |
| Issue: | Volume: 2-4-A Fast Numerical Analysis for Electromagnetic Radiation and Scattering Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 372 KB |
| Title: | Synthesis of Elliptical Antenna Array using Hybrid SSWOA Algorithm |
| Abstract: | In terms of research, the elliptical antenna arrays (EAA) synthesis is relatively novel. As it does not have to be circular in construction, this novel synthesis can maneuver the primary beam in the right direction, making it easier to realize. The amplitude and angular location of the ellipse, as well as the eccentricity of the ellipse, are all taken into account in the optimization process. The proposed hybrid algorithm is the SSWOA (Salp Swarm Whale Optimization Algorithm), which combines the Salp Swarm Optimization Algorithm (SSA) with the Whale Optimization Algorithm (WOA). The SSA algorithm serves as a guide, while the WOA algorithm serves as a helper in this method. We discover that optimization has a faster convergence time and high convergence accuracy when considering the benefits of SSA and WOA and applying them to the synthesis of antenna array layouts. If Griewank, Rosenbrock, Sphere, and Rastrigin test functions are used, it’s worth noting that the hybrid method outperforms both WOA and SSA. |
| Author(s): | D. Prabhakar, K. Srinivas, S. Ratna Spandana, D. Anusha, M. V. Srikanth, Y. Rama Krishna |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 5 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 2681 KB |
| Title: | Synthesis of Approximate Flat-top Pattern for Efficient Microwave Power Transmission |
| File Type: | Conference Paper |
| Issue: | Volume: 3-MA-5 Wireless Power Transmission Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 215 KB |
| Title: | Susceptibility of a Simple Transmission Line Inside an Enclosure Against Normal Incident Plane Wave |
| Abstract: | In this paper, susceptibility of a Microstrip Transmission Line (MTL) as a simple Printed Circuit Board (PCB) against a normal incident plane wave is studied. Here, the induced voltage on the open port of the MTL is considered as the susceptibility criterion for the MTL. Two different approaches are applied: the Method of Moments (MoM) and the Finite Integration Technique (FIT). In addition to simulations, we performed measurements inside a semi-anechoic chamber. Both simulations show very good agreement with the measurements. In addition to frequency domain results, time domain induced open circuit voltage is calculated. The effect of different aperture sizes on the susceptibility of a shielded MTL is examined. It is shown that large apertures can multiply the disagreeable effect of the interfering wave on the MTL, compared to the case where no shield is utilized. |
| Author(s): | S. Abadpour, P. Dehkhoda, R. Moini, S. H. H. Sadeghi, H. R. Karami |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 5 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1039 KB |
| Title: | Surface Plasmon Resonance Based on Attenuated Total Reflection |
| File Type: | Conference Paper |
| Issue: | Volume: 1-SP-3 Advances in Electromagnetic Theory and Simulation Techniques I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 394 KB |
| Title: | Spread Spectrum Time Domain Reflectometry and Steepest Descent Inversion Spread Spectrum Time Domain Reflectometry and Steepest Descent Inversion |
| Abstract: | In this paper, we present a method for estimating complex impedances using reflectometry and a modified steepest descent inversion algorithm. We simulate spread spectrum time domain reflectometry (SSTDR), which can measure complex impedances on energized systems for an experimental setup with resistive and capacitive loads. A parametric function, which includes both a misfit function and stabilizer function, is created. The misfit function is a least squares estimate of how close the model data matches observed data. The stabilizer function prevents the steepest descent algorithm from becoming unstable and diverging. Steepest descent iteratively identifies the model parameters that minimize the parametric function. We validate the algorithm by correctly identifying the model parameters (capacitance and resistance) associated with simulated SSTDR data, with added 3 dB white Gaussian noise. With the stabilizer function, the steepest descent algorithm estimates of the model parameters are bounded within a specified range. The errors for capacitance (220pF to 820pF) and resistance (50 Ω to 270 Ω) are < 10%, corresponding to a complex impedance magnitude |R +1/jωC| of 53 Ω to 510 Ω. |
| Author(s): | S. R. Kingston, H. Ellis, M. U. Saleh, E. J. Benoit, A. Edun, C. M. Furse, M. A. Scarpulla, J. B. Harley |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 2 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1409 KB |
| Title: | Splitting of Material Cells and Averaging Properties to Improve Accuracy of the FDTD Method at Interfaces |
| Abstract: | In this paper we present a simple modification to the traditional Finite Difference Time Domain (FDTD) method for treating material cells. The Yee cell is split into 8 smaller material subcells so that each E and H field point is considered to be located at the crosspoint of 8 cells with differing material properties. Thus there is no longer an overlap of the material cells associated with the components of the E and H fields. The 8 material properties are averaged at each crosspoint. Since the averaging is done outside the time marching loop there is little increase in the total computational time. Numerical results are shown for a sinusoidal plane wave scattering from a dielectric sphere. These results are compared with the exact Mie solution and the traditional material cell method along different cuts through the sphere. The splitting and averaging is shown to give improved amplitude accuracy in the vicinity of the sphere. Improvement is also observed at planar interfaces angled with respect to the grid. An additional benefit of this subcell formulation is that objects may be modeled with twice the geometrical resolution without increasing the size of the staggered grid. |
| Author(s): | R. S. Schechter, M. Kragalott, M. S. Kluskens, W. P. Pala, R. S. Schechter, M. Kragalott, M. S. Kluskens, W. P. Pala |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 3 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 277 KB |
| Title: | Some Considerations on Passive Intermodulation of Material Nonlinearity in Microwave Circuits and Devices |
| File Type: | Conference Paper |
| Issue: | Volume: 8-TP-4 In Celebration of 70th Birthday of Prof. Jia-dong Xu II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 9 KB |
| Title: | Some Considerations on Passive Intermodulation of Material Nonlinearity in Microwave Circuits and Devices |
| File Type: | Conference Paper |
| Issue: | Volume: 10-TE-4 In Celebration of 70th Birthday of Prof. Jia-dong Xu III Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 9 KB |
| Title: | Small-Size Tapered Slot Antenna (TSA) Design for use in 5G Phased Array Applications |
| Abstract: | The design and development of a compact tapered slot antenna (TSA) for the fifth generation (5G) phased array communications is described in this manuscript. The proposed low-profile TSA element is designed on a Rogers RT 5880 (?=2.2 and ?=0.0009) dielectric to work in the frequency range from 21 to 23 GHz. The configuration of the employed TSA antenna elements is composed of a slot-line flare from a small gap to a large opening, matching to free space’s wave impedance. Eight TSA elements with well-defined endfire radiation patterns have been used on the top portion of a mobile-phone PCB to form a 1×8 linear phased array. The TSA elements are fed by hockey-stick baluns. In addition, the radiation performance and SAR characteristics of the phased array 5G antenna in the vicinity of user’s hand & head have been investigated in this study. The results show that the proposed design provides good characteristics in terms of S-parameters, antenna gain, efficiency, SAR, and beam steering, which fit the need of 5G cellular communications. |
| Author(s): | N. O. Parchin, M. Shen, G. F. Pedersen |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 3 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 2330 KB |
| Title: | Single Feed Dual-Polarization Dual-Band Transmitarray for Satellite Applications |
| Abstract: | In this paper, two transmitarrays are designed, analyzed, and simulated for satellite applications. The first transmitarray is designed for dual linear polarization at a center frequency of 12 GHz. The second transmitarray is designed for two frequency bands: 17.15 GHz to 17.9 GHz for vertical polarization and 11.5 GHz to 12.4 GHz for horizontal polarization. The dual polarization is obtained by an independent adjustment of the dimensions of two orthogonal slots in the transmitarray unit cell. The design is carried out independently for each polarization. The transmitarray unit cell uses two dielectric substrate layers arranged to be one on each side of a conducting plane. On each substrate, one face has metallization containing the patches, and the other face has metallization containing the ground plane. The two patches are coupled by two cross slots of lengths LV and LH in the ground plane and each patch is loaded with two cross slots of lengths LV/2 and LH/2. The unit cell achieves 360o of phase agility with less than 3.8 dB of variation in the transmission magnitude in the tuning range. The transmitarray consisted of 17×17 elements with the unit cell size were set at 13 mm. A circular feed horn is located on the central normal to the transmitarray and the configuration looks like a lens antenna. Two separate feeding pins are used to excite the horn antenna for horizontal and vertical polarizations. The results are worked out using two basically different numerical techniques, the finite element method, FEM, and the finite integration technique, FIT. Good agreement was obtained. |
| Author(s): | S. Zainud-Deen, S. Gaber, H. Malhat, K. Awadalla |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 353 KB |
| Title: | Simulation of Scattering Problems in Time Domain Using a Hybrid FDTD UTD Formulation |
| File Type: | Conference Paper |
| Issue: | Volume: Wavelets in Electromagnetics Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 209 KB |
| Title: | Rotman Lens Amplitude, Phase, and Pattern Evaluations by Measurements and Full Wave Simulations |
| Abstract: | Microwave lens’ performance is depicted by several parameters such as phase error, amplitude taper, and array scan pattern etc. For decades, these parameters have been estimated by the geometry optics method that does not capture the mutual couplings within the lens geometry. Full wave simulation toolkits to conduct EM prediction are now available. However, using them to synthesize and optimize the electrical performance of Rotman lens is still relatively new. Several microwave lens full wave simulations have been attempted using different methods, such as FDTD, FEM, and FIT. They were reported from the perspectives of either phase or amplitude predictions at a single port or single frequency. However, the lens properties at multiple frequencies and for multiple beam ports using MoM have not been investigated. In this paper, we address such simulations using the planar Green’s function in FEKO. The phase, amplitude and array factor across the frequency band for multiple beam ports are compared with the measured results, and their errors are evaluated. Prominent agreement between FEKO and measurement is demonstrated. The performance of a prototype lens is presented, followed by discussing few future aspects of lens optimization using full wave simulations. |
| Author(s): | J. Dong, A. I. Zaghloul, R. Sun, C. J. Reddy, S. J. Weiss |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 6 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 1200 KB |
| Title: | Reverse Operation Self-consistent Evaluation Applied to IE-DDM with Phase Extracted Basis Function |
| File Type: | Conference Paper |
| Issue: | Volume: S58 Recent Advances on Characteristic Mode Analysis and Applications Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 209 KB |
| Title: | Resonant Frequency Analysis using Perturbation and Resonant Cavity Method in Printed Dual Band Antenna for WiMAX Application |
| Abstract: | A printed dual-band antenna is designed to resonate at 3.5 GHz with the measured gain of 6.38 dBi and at 5.5 GHz with that of 5.84 dBi for the WiMAX application. The bandwidth of this antenna at 3.5 GHz and 5.5 GHz is 8% and 5%, respectively. The radiation efficiency of 91.45% is obtained at 3.5 GHz and that of 89.56% at 5.5 GHz. A novel approach based on the perturbation technique is used to relate the resonant frequency to the electromagnetic energy stored and the volume of the proposed antenna’s structure. The dual resonant length of this antenna is determined by a parameter named as the length reduction factor, which is computed by the curve fitting method. A polynomial equation connects the length reduction factor and resonance frequency. The resonant cavity model has been used to derive the resonant frequency equations for dual bands. The simulation and measured results are used to validate the analytically predicted resonant frequency caused by the structure perturbation and cavity technique and show good agreement. This antenna is fed by a balanced parallel plane, which conveniently facilitates the PCB’s integration. |
| Author(s): | C. Mahendran, M. Vijayaraj |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 2 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 4370 KB |
| Title: | Removing the Froissart Doublets in a Rational Interpolation Based on Loewner Matrix |
| Abstract: | In order to implement wide band frequency sweeping, the S-parameters can be fitted with an adaptive rational interpolation based on Loewner matrix. However, the errors in the sampling data may lead to Froissart doublets, which look like spikes in the curve. In this paper, a novel technique is proposed to remove these doublets. At first, the rational expression is converted into the sum of partial fractions by solving two generalized eigenvalue problems. After that, the partial fraction term with the smallest imaginary part of the pole and relatively large absolute value is considered to generate the doublets. Removing this term results in a smooth rational polynomial, which is validated by the example of a passive circuit simulated by finite element method (FEM). |
| Author(s): | H. Yuan, J. Ren, Y. Li, X. Huang |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 1 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 2992 KB |
| Title: | Relationship Between the Path Loss Exponent and the Room Absorption for Line-of-Sight Communication |
| Abstract: | In indoor propagation, the log-distance path loss model represents the received power as declining with distance from the transmitter according to1/ r n , where r is the straight-line distance from the transmitter to the receiver. Previously, the value of the path loss exponent n has been derived from measured received signal strengths at a specific site. In this paper, the value of n is estimated from the geometry of the room and the electrical properties of the walls. Using the Sabine model, these determine the room absorption and hence the received power as a function of distance from the transmitter. Then, a least-square-error curve fit of the logdistance path loss model to the Sabine model determines the value of n . The electric field strength in a typical rectangular room is compared using ray tracing, the Sabine model, and the path loss model. Then the value of the path loss exponent is presented as a function of the power absorption coefficient of the walls, floor and ceiling of the room, for a typical ceiling height. Evaluating n from analytic information rather than from measurement enhances the usefulness of the path loss model in simulations of the coverage of antennas for the design of wireless local area network installations at specific sites. |
| Author(s): | C. W. Trueman, D. Davis, B. Segal |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 4 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 181 KB |
| Title: | Radiation Characteristics of Cylindrical Dielectric Resonator Antenna Mounted on Superquadric Cylindrical Body |
| File Type: | Conference Paper |
| Issue: | Volume: Dielectric Resonator Antennas Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 210 KB |
| Title: | Protective Role of Vitamin C in Wi-Fi Induced Oxidative Stress in MC3T3-E1 Cells in Vitro |
| Abstract: | The increasing convenience and benefits provided by wireless technology innovations may also affect the human health because of Wi-Fi electromagnetic radiation. The effects of 2.45 GHz Wi-Fi on oxidative stress (OS) in MC3T3-E1 cells and the protective role of vitamin C are presented and analyzed in this paper. MC3T3-E1 cells were exposed to 100 mW and 500 mW 2.45 GHz Wi-Fi signals at specific absorption rates (SARs) of 0.1671 W/kg and 0.8356 W/kg, referred to as SARa and SARb, respectively, for 0-180 minutes to determine the optimal irradiation time by testing reactive oxygen species (ROS) and glutathione (GSH). Following irradiation for the optimal irradiation time, ROS levels were assayed for 0-120 min after each irradiation. Additional vitamin C is added to the medium to investigate the effect on ROS and GSH. A FDTD simulation showed that the cell layer temperature increased by 0.1°C and 0.5°C after being exposed in the SARa and SARb for the optimal irradiation time (90 min). Ninety min of Wi-Fi irradiation provoked an obvious increment in ROS and GSH on the first day, and the ROS level returned to the initial level 30 min after the irradiation; however, on the third day, it took 90-120 min for ROS to return to baseline. Vitamin C significantly reduced ROS levels and recovery times. In conclusion, 2.45 GHz Wi-Fi radiation triggered oxidative stress in osteoblasts 3cm from the source antenna. Vitamin C effectively reduced the ROS levels stimulated by nonthermal effects of Wi-Fi irradiation. |
| Author(s): | M. Wang, G. Yang, Y. Li, Q. Wu, Y. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 5 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 21794 KB |
| Title: | Printable Chipless Tag and Dual-CP Reader for Internet of Things |
| Abstract: | This paper proposes a printable chipless tag that encodes more bits than a conventional tag, and also a dual circularly polarized (CP) reader that achieves high isolation with insensitive orientation. To demonstrate this concept, a radio-frequency identification (RFID) tag of 13mm×13mm is designed to encode 5 bits covering 6 - 9 GHz. This tag is investigated and measured with dual- CP backscattering characteristics for the first time. The versatile dual-CP reader, along with this tag which is feasible to print on other flexible substrate including papers, clothes and plastics, are promising to benefit the Internet of Things (IoT). |
| Author(s): | G. Dong, Y. Shen, H. Meng, N. Chen, W. Dou, S. Hu |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 5 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1942 KB |
| Title: | Price-Performance Aspects of Accelerating the FDTD Method Using the Vector Processing Programming Paradigm on GPU and Multi-Core Clusters |
| Abstract: | The parallelization of the FDTD on GPUs has become popular due to the low cost, low power and high compute performance achieved with these devices. In recent years, manufacturers of multi-core processors have enhanced the vector processing capability inherent in conventional processing cores, to the extent that these are now contributing considerably to the acceleration of the FDTD and competing with GPUs. This paper will compare the power consumption and purchase cost versus the performance benefits of several parallel FDTD implementations, in order to quantify the effect of parallelizing the FDTD using various processing paradigms. The purchase cost of hardware, computational performance and power consumption are used to compare the parallel FDTD deployments on the BlueGene/P, GPU clusters and the multi-core clusters using SSE. It is shown that the deployment of the parallel FDTD using a hybrid programming paradigm achieves the best computational performance for the lowest purchase cost and power consumption |
| Author(s): | R. G. Ilgner, D. B. Davidson |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 5 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 653 KB |
| Title: | Planar Circular Monopole Antenna with Perforated Dielectric Resonator for Notched Ultra-Wide Band Applications |
| Abstract: | In this paper, a planar circular patch antenna is presented for UWB operating characteristics. The bandwidth of the proposed antenna is increased by inserting a perforated dielectric resonator (DR) material with the planar monopole. The design combines the advantages of a small size dielectric resonator (DR) and thin planar monopole antennas. Two antenna designs A and B are proposed. In design A, two layers of the same dielectric material are presented with the same radius and different thicknesses. While in antenna design B, only one dielectric material layer perforated by 11 holes drilled with the same radius is considered. The effects with respect to the geometric parameters of the proposed antennas on impedance bandwidth and radiation pattern are discussed. In addition, the two proposed antennas are designed to have a rejection frequency band from 5 to 6 GHz by inserting two U-shaped slots in the ground plane, where the WLAN service is allocated. The proposed antennas are completely designed and analyzed using the finite element method (FEM), and then the finite integral transform (FIT) technique is used to check the validity of the numerical results. |
| Author(s): | S. H. Zainud-Deen, A. Shaker, K. R. Mahmoud |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 6 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 1008 KB |
| Title: | Physics-Based Modeling of Power Converter Drive System for Evaluation of Electromagnetic Compatibility |
| Abstract: | In this paper, detailed physics-based modeling of a power converter drive is proposed. The 3D finite element (FE) modeling of a power inverter was developed and analyzed. An approach in physical modeling of the switching activity of the inverter in FE is proposed. In addition, the solver was modified and implemented for analyzing nonlinear materials in timeharmonic cases to achieve faster computation. The frequency response analysis was also implemented in simulation and measurements at various locations from the source. The numerical simulation provided the exact field solution at any given distance and defined the correlation between the electromagnetic fields generated by each of these components. The importance of this work is to facilitate the ability to evaluate the stray electromagnetic field levels used for evaluating EMC compliance at the design stage. In addition, the recognition of a failure condition inside each component of the system by observing the fields is another important contribution of this work. The optimum operation of the system components for lower EMI and optimum design of related shielding for EMC evaluation studies are added benefit of this work. |
| Author(s): | M. R. Barzegaran, A. Nejadpak, O. A. Mohammed |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 3675 KB |
| Title: | Photogrammetry-based Surface Reconstruction for Improving Microwave Breast Tumor Detection |
| File Type: | Conference Paper |
| Issue: | Volume: Microwave Imaging and Inverse Problems Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 329 KB |
| Title: | Performance of Multiple-Feed Metasurface Antennas with Different Numbers of Patch Cells and Different Substrate Thicknesses |
| Abstract: | The design and performance of low-profile, multiple-feed metasurface antennas with different numbers of patch cells and different substrate thicknesses at a terahertz frequency are presented in this paper. The utilized antenna designs consist of a periodic array (N × M) metallic square-patch metasurface and a planar feeding structure, which are both patterned on an electrically thin, high-permittivity GaAs substrate. The antenna gain increased in a linear fashion with an increasing number of patch cells, which were directly fed by the slit feedline. A 3-dB gain increment was observed irrespective of the substrate thickness when the number of patch cells was doubled. However, the 3-dB gain bandwidth as well as the radiation efficiency changed significantly with varying substrate thicknesses. The described antenna structure offers useful characteristics by means of a combination of different substrate thicknesses and patch numbers. In addition, the proposed antenna design features a number of benefits, including a low profile, mechanical robustness, easy integration into circuit boards, and excellent suitability for low-cost mass production. |
| Author(s): | N. Hussain, I. Park |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 1 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1747 KB |
| Title: | Performance of Multiple-Feed Metasurface Antennas with Different Numbers of Patch Cells and Different Substrate Thicknesses |
| Abstract: | The design and performance of low-profile, multiple-feed metasurface antennas with different numbers of patch cells and different substrate thicknesses at a terahertz frequency are presented in this paper. The utilized antenna designs consist of a periodic array (N × M) metallic square-patch metasurface and a planar feeding structure, which are both patterned on an electrically thin, high-permittivity GaAs substrate. The antenna gain increased in a linear fashion with an increasing number of patch cells, which were directly fed by the slit feedline. A 3-dB gain increment was observed irrespective of the substrate thickness when the number of patch cells was doubled. However, the 3-dB gain bandwidth as well as the radiation efficiency changed significantly with varying substrate thicknesses. The described antenna structure offers useful characteristics by means of a combination of different substrate thicknesses and patch numbers. In addition, the proposed antenna design features a number of benefits, including a low profile, mechanical robustness, easy integration into circuit boards, and excellent suitability for low-cost mass production. |
| Author(s): | N. Hussain, I. Park |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 3 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1810 KB |
| Title: | Performance of Digital Transceiver for Space-Time Coded Cooperative Multihop Wireless Communication Systems |
| File Type: | Conference Paper |
| Issue: | Volume: System Architectures and Analysis Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 187 KB |
| Title: | Pattern Reconstruction for Antennas with Characteristic Mode Analysis and Surrogate Model |
| Abstract: | A novel approach is applied to obtain a desired pattern for a perfect electric plate with two ports. The location of ports is decided with the help of characteristic mode analysis. Two capacitive coupling elements are chosen to be used as excitation. The magnitude and phase of each excitation are obtained by the Bayesian inference method. In order to avoid complexity of computational design, a surrogate model, which is based on polynomial chaos expansion, is built. The surrogate model is ensured to mimic the computational model over 90%. Then, the desired pattern is compared with the synthesized one, and it is seen that the two patterns fit very well to each other and the correlation between the two patterns is above 0.9. |
| Author(s): | A. Yilmaz, H. Acikgoz, A. E. El-Rouby |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 3 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 1116 KB |
| Title: | Passive time-domain macromodeling of large complex interconnects |
| File Type: | Conference Paper |
| Issue: | Volume: Black Box Modeling Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 650 KB |
| Title: | Parameter Identification of the Planar Integrated EMI Filter Based on the Improved Immune Algorithm |
| Abstract: | The planar integrated EMI filter has been widely used because of its small size and good highfrequency characteristics. During the production process, if the electrical parameters of the integrated LC structure can be accurately identified, it will help improve the high-frequency characteristics of the filter. However, this identification problem is a multi-peak problem, which can easily fall into a local optimal solution. Based on the Feature Selective Validation method, this paper proposes an improved Immune Algorithm. The proposed method keeps changing the fitness function in the iterative process to avoid the algorithm falling into the local optimal solution. Finally, comparing with the measured impedance characteristic curve, it is verified that the proposed method is more accurate than the common Immune Algorithm. |
| Author(s): | J. Bai, H. Zhao, Y. Liu, K. Guo |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 1 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1284 KB |
| Title: | Parallel PSO/FDTD Algorithm for the Optimization of Patch Antennas and EBG Structures |
| File Type: | Conference Paper |
| Issue: | Volume: Special Session: Communication Antenna Analysis and Design Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 291 KB |
| Title: | Optimizing Processing Time of Radio-Astronomy Antenna Simulations Using FEKO |
| Abstract: | The far-field pattern of a geometrically large and complex antenna used in low-frequency radio astronomy is computationally expensive to simulate on electromagnetic simulators, such as FEKO. For example, one station of the Square Kilometer Array, which consists of 256 log-periodic antenna elements, will take years to simulate using the full CAD model for the full operational frequency band. This paper focuses on reducing the simulation time for a single antenna element by simplifying the simulation model, thus decreasing the number of unknowns that have to be solved in a simulation. An iterative process for optimizing the simplification of such an element is described, while keeping the reflection coefficient within 1 dB absolute mean deviation of the measured data. After four iterations, the amount of unknowns to be solved, which includes the number of triangles and segments, was reduced from 29,307 to 11,991. This decreased the computation time by 86.5%, making array simulations feasible. Using the techniques described in the paper, other antenna constructions can benefit from it and be simulated more efficiently. |
| Author(s): | R. Steiner, D. C. X. Ung, A. Hubrechsen, R. D. Jones, R. B. Wayth, M. J. Bentum, A. B. Smolders |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 10 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 2485 KB |
| Title: | Optimizing Optical Negative Index Materials: Feedback from Fabrication |
| File Type: | Conference Paper |
| Issue: | Volume: Nature-Based Stochastic Optimization Methods Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 1090 KB |
| Title: | Optimization of Frequency Selective Surface with Simple Configuration Based on Comprehensive Formation Method |
| Abstract: | A new approach to design a frequency selective surface (FSS) is presented based on optimizing the shape of its unit cell geometry. A method based on spline concept has been adopted to specify geometrical features of the elements. In the design process, a hybrid optimization process including genetic algorithm and pattern search method has been used for this purpose. The shape of the structure is improved in each iteration based on specific fitness function. The commercial software CST is used for accurate analysis of structures along the optimization process. A VBA code is developed in order to link Matlab code, which includes optimization tools, and analyzer software CST. This method is used to develop band-pass and band-stop FSSs. Our simulated results show that the transmission and reflection characteristics of the designed FSS are very good in specified frequency band. |
| Author(s): | N. F. Amini, M. Karimipour, K. Paran, S. Chamani |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 4 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 406 KB |
| Title: | Optimization of a Microstrip Matching Circuit at Two Frequencies Using Taguchi\'s Method |
| File Type: | Conference Paper |
| Issue: | Volume: EM Applications in Sonnet Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 167 KB |
| Title: | Optimization of a Dual-Band, Printed Octafilar Antenna |
| Abstract: | This paper presents several innovative techniques for the design and optimization of a dual band, octafilar helix antenna. The technical challenge of this design is how close the two bands of operation are, as well as the requirement to fit inside a radome with .07λ diameter and .33λ length. This was achieved through a novel technique of applying differing pitches and terminations to the upper and lower frequency antenna filars and then feeding them from a similar location at the base. This allowed for optimal current distribution on each of the two antenna filars. The final design produced gain greater than 0dBic at zenith across both bands of operation. The techniques discussed in this paper were seen to grow low frequency performance by as much as 2.5dBic over a typical octafilar design of the same size. |
| Author(s): | J. D. Majkowski |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 12 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2573 KB |
| Title: | Optimal Design of Microwave Devices by Fitness-estimation-based Particle Swarm Optimization Algorithm |
| Abstract: | As important parts of modern communication systems, microwave devices play a decisive role in communication quality. When optimizing the complex microwave devices, the global optimization algorithm is generally used exploiting full-wave electromagnetic simulation software. The full-wave electromagnetic simulation software evaluates the performance of the microwave device. Based on this evaluation result, the global optimization algorithm is used to design the microwave device. This ordinary method can achieve high accuracy, but the main disadvantage is time-consuming. It takes a long time and sometimes takes days or even weeks. In order to improve the efficiency of the optimization of microwave devices, this research presents a method called fitness-estimation-based particle swarm optimization (fePSO). According to the explicit evolution formula of particle swarm optimization (PSO), the particles fitness predictive model is constructed. From the third generation, the fitness value is estimated by the predictive model, so as to replace the time-consuming full-wave electromagnetic simulation when optimizing complex microwave devices. Thereby it can greatly reduce the evaluation time of the fitness, shorten the entire optimization process, and improve the design efficiency. This method is validated by optimizing Yagi microstrip antenna (MSA) and hairpin SIR band-pass filter. The results show that the efficiency can be increased by about 90% with the assurance of design accuracy, so the purpose of rapid optimization has been achieved. |
| Author(s): | X.-H. Fan, Y.-B. Tian, Y. Zhao |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 11 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1946 KB |
| Title: | On the Diversity Gain Using a Butler Matrix in Fading MIMO Environments |
| File Type: | Conference Paper |
| Issue: | Volume: MIMO and Diversity System Characterization Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 310 KB |
| Title: | On the Design and Simulation of Antennas on Ultra-thin Flexible Substrates |
| Abstract: | Flexible wireless systems are rapidly evolving in a wide spectrum of applications such as medical, entertainment and sport facilities. The aim of this paper is to investigate whether the ultra-thin substrates along with their permittivity are essential for the initial design stage of a flexible antenna, which is a key element of any wireless system, or it is merely a supporting structure. Three state-of-the-art simulation tools are used to evaluate the scattering parameter, S11 which are then compared against precise measurements conducted inside an anechoic chamber. These methods are the Finite Integration Technique (FIT) based Time Domain Solver (TDS) and the Finite-Element Method (FEM) based Frequency Domain Solver (FDS) of CST Microwave Technology and the (FEM) based HFSS of ANSYS. This paper attempts to provide an answer as to whether the substrate and other geometrically small features such as the feeding structure should be sufficiently discretized or else conventional default adaptive meshing should be enough. Three different flexible antennas with two fabrication techniques and feed lines have been used in the simulations and measurements. |
| Author(s): | A. Kashkool, S. Yahya, H. Al-Rizzo, A. Al-Wahhamy, A. A. Issac |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 7 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1629 KB |
| Title: | On the Design and Simulation of Antennas on Ultra-thin Flexible Substrates |
| Abstract: | Flexible wireless systems are rapidly evolving in a wide spectrum of applications such as medical, entertainment and sport facilities. The aim of this paper is to investigate whether the ultra-thin substrates along with their permittivity are essential for the initial design stage of a flexible antenna, which is a key element of any wireless system, or it is merely a supporting structure. Three state-of-the-art simulation tools are used to evaluate the scattering parameter, S11 which are then compared against precise measurements conducted inside an anechoic chamber. These methods are the Finite Integration Technique (FIT) based Time Domain Solver (TDS) and the Finite-Element Method (FEM) based Frequency Domain Solver (FDS) of CST Microwave Technology and the (FEM) based HFSS of ANSYS. This paper attempts to provide an answer as to whether the substrate and other geometrically small features such as the feeding structure should be sufficiently discretized or else conventional default adaptive meshing should be enough. Three different flexible antennas with two fabrication techniques and feed lines have been used in the simulations and measurements. |
| Author(s): | A. Kashkool, S. Yahya, H. Al-Rizzo, A. Al-Wahhamy, A. A. Issac |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 7 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1629 KB |
| Title: | Octafilar Helical Antenna for Handheld UHF RFID Reader |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Antenna Design and Applications Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 245 KB |
| Title: | Novel Hardware Platforms for Shipboard Modeling of Electromagnetic Phenomena |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling EM in Maritime Enviroment Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 91 KB |
| Title: | Non-conformal IE-PE-DDM using Reverse Operation Self-consistent Evaluation |
| File Type: | Conference Paper |
| Issue: | Volume: 2-1-A Brainstorm for Computational Electromagnetics: What We Have Achieved and What We Will Do I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 272 KB |
| Title: | NF–FF Transformation with Bi-Polar Scanning From Nonuniformly Spaced Data |
| Abstract: | An efficient probe compensated near-field–far-fieldtransformation technique from irregularly spaced bi-polar samples is developed in this paper. The singularvalue decomposition method is applied to recover theuniformly distributed data, whose position is fixed by anonredundant sampling representation of theelectromagnetic field. Then an optimal samplinginterpolation algorithm is used for reconstructing theplane-rectangular samples required to carry out thestandard near-field–far-field transformation. This laststep is required to benefit by the use of FFT algorithm.Numerical examples are reported to assess theeffectiveness of the proposed technique. |
| Author(s): | F. Ferrara, C. Gennarelli, M. Iacone, G. Riccio, F. Ferrara, C. Gennarelli, M. Iacone, G. Riccio |
| File Type: | Journal Paper |
| Issue: | Volume: 20 Number: 1 Year: 2005 |
| Download Link: | Click here to download PDF File Size: 226 KB |
| Title: | New Technique to Design Fresnel Zone Plate Antennas |
| Abstract: | A new method to design Fresnel Zone Plate Antennas (FZPA) is presented in this paper. The proposed method is based on deforming a flat metallic surface in order to achieve the desired phase distribution required to point the main beam to a certain direction. The resulting shaped reflector is modeled by using parametric surfaces, since they allow fitting the real shape of the antenna accurately providing smooth variations. Therefore, the diffraction effect that appears in the transition region between Fresnel zones can be reduced. Unlike bulky parabolic reflectors, FZPAs are much smaller and easy to transport and support, being a promising candidate for satellite communication applications due to its high gain, high polarization purity and minimum volume. |
| Author(s): | J. Gomez, A. Tayebi, F. Catedra |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 3 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 463 KB |
| Title: | Mutual Coupling Reduction in CBS Antenna Arrays by Utilizing Tuned EM-EBG and Non-planar Ground Plane |
| Abstract: | Radiation surface wave (surface current) on ground plane has a destructive effect on the characteristics of antennas which benefits from a common ground plane, especially Cavity Backed Slot (CBS) antennas. Surface current increases mutual coupling in an antenna array. This in turn causes unwanted characteristics in array applications. The main goal of this work is to design a new modified antenna array achieving less mutual coupling by reshaping ground plane and using tuned Elongated Mushroom Electromagnetic Band Gap (EM-EBG). Moreover, in this study, we focus on the influence of changing depth of EM-EBG holes. In this regard, four different designs for CBS antenna arrays are investigated. The results reveals that by using two new methods, namely stepped ground plane and tuned EMEBG, mutual coupling will be decreased by more than 9 dB. Decrement of mutual coupling improve radiation characteristic of array such as Front to Back Ratio (FBR) by 8 dB. The effectiveness of our design is confirmed by experimental results. |
| Author(s): | S. Manshari, F. H. Kashani, G. Moradi |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 7 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1270 KB |
| Title: | Multidomain Basis functions devoted to Antenna Siting Electromagnetic Modelling |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Computational Techniques in Electromagnetics - 2 Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 1890 KB |
| Title: | Modeling the Performance Impact of Anisotropic Unit Cells Used in Additively Manufactured Luneburg Lenses |
| Abstract: | Additively manufactured graded index lenses, such as the Luneburg lens, often result in some degree of uniaxial anisotropy in the effective permittivity distribution. A uniaxially anisotropic Luneburg lens modifies the polarization state of an incident electromagnetic field, thus giving rise to a polarization mismatch at the receiving antenna. Using 3D finite element simulation, the lens focal point polarization is analyzed and a model that fits the simulation data is created. The model allows prediction of polarization mismatch loss given any incident field and any receiving antenna polarization without resorting to further time-consuming simulations. |
| Author(s): | B. F. LaRocca, M. S. Mirotznik |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 1 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 582 KB |
| Title: | Modeling and Optimization of MEMS Devices Using the Lumped Element Equivalent Circuit Approach |
| File Type: | Conference Paper |
| Issue: | Volume: Novel Modeling Techniques and RF MEMS Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 150 KB |
| Title: | Modeling and Design of Frequency Independent Antennas for Millimeter Wave Electronic Warfare and UHF Platform Integration |
| File Type: | Conference Paper |
| Issue: | Volume: EM Simulations Using FEKO Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 527 KB |
| Title: | MODEL-BASED PARAMETER ESTIMATION IN ELECTROMAGNETICS: III--Applications to EM Integral Equations |
| Abstract: | Problem solving in electromagnetics, whether by analysis, measurement or computation, involves not only activities specific to these particular categories, but also some concepts that are common to all. Fields and sources are sampled as a function of time, frequency, space, angle, etc. and boundary conditions are satisfied through mathematical imposition or experimental conditions. The source samples, usually the unknowns in a problem, are found numerically or analytically by requiring them to satisfy both the appropriate form of Maxwell's Equations as relationships between them, together with the applicable boundary conditions. Alternatively, source samples may be measured under prescribed experimental conditions. These sampled relationships can be interpreted from the viewpoint of signal and information processing, and are mathematically similar to various kinds of filtering operations. It is this similarity that is discussed here in the context of modelbased parameter estimation, where the dependence of electromagnetic fields and sources that produce them are both regarded as generalized signals. MBPE substitutes the requirement of obtaining all samples of desired quantities (physical observables such as impedance, gain, RCS, etc. or numerical observables such as impedance-matrix coefficients, geometrical-diffraction coefficients, etc.) from first-principles models (FPMs) or from measured data (MD) by instead using a reduced-order, physically-based approximation, a fitting model (FM), to interpolate between, or extrapolate from, FPM or MD samples. When used for electromagnetic observables, MBPE can reduce the number of samples that are required to represent responses of interest, thus increasing the efficiency of obtaining them. When used in connection with the FPM itself, MBPE can decrease the computational cost of its implementation. Some specific possibilities for improving FPM efficiency are surveyed, specifically in terms of using FMs to simplify frequency and spatial variations associated with FPMs. Examples of MBPE applications are included here as well as speculative possibilities for their further development in improving FPM performance. [Vol. 10, No. 3 (1995), Special Issue on Advances in the Application of Method of Moments to Electromagnetic Radiation and Scattering Problems, pp 9-29] |
| Author(s): | E. K. Miller, E. K. Miller |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 3 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 2214 KB |
| Title: | Model-assisted Evaluation of the Reliability of an Eddy Current Nondestructive Evaluation Technique |
| File Type: | Conference Paper |
| Issue: | Volume: Nondestructive Evaluation and Materials Characterization I Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 192 KB |
| Title: | Mode Tracking for Parametrized Eigenvalue Problems in Computational Electromagnetics |
| Abstract: | An algorithm to perform a mode tracking for parameter dependent eigenvalue problems in computational electromagnetics is presented. It is based on a Taylor expansion using the derivatives of the eigenvalue and the eigenvector and allows distinguishing between intersection and touching points in the eigenvalue curves. The method is applied to discretizations with both the finite integration technique (FIT) and the finite element method (FEM), leading to simple and generalized eigenvalue problems, respectively. The applications include the calculation of the Brillouin diagram for a periodic structure and the variation of a material parameter in a filter structure. |
| Author(s): | P. Jorkowski, R. Schuhmann |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 2 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1263 KB |
| Title: | Miniaturization and Optimization of Meander-line Dipole Antenna Arrays via Orthogonal Array Initialized Hybrid Particle Swarm Optimizer |
| File Type: | Conference Paper |
| Issue: | Volume: Optimization Methods for Electromagnetics Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 437 KB |
| Title: | Miniature Dual Band Button Antenna Using Cylindrical Dielectric Resonator Antenna for On/Off Body Communication Devices |
| Abstract: | This paper presents miniature dual-band cylindrical dielectric resonator antenna (CDRA) based on button antenna for wireless body area network (WBAN) applications. A button antenna is designed by stacking two CDRAs (low and high permittivity) fed by coaxial probe through the ground plane and penetrates the bottom CDRA. The prime contributions of using DRAs are to enhance the performance and to provide a compact size of antenna. However, the coaxial probe realizes two radiation patterns, monopole and broadside patterns. A comprehensive validation using CST microwave studio is carried out to determine the characteristics of the proposed button antenna. In addition, to ensure that the results are acceptable to the practitioner in this field, a prototype was fabricated and tested. The superiority of the proposed antenna is confirmed by possessing 39% more compact size compared to previously reported studies, efficiency of more than 63% and bandwidth of 4.9% and 6.6% for lower and upper band, respectively. This proposed design is a promising candidate to benefit on/off body communication devices operating at 2.4 and 5.6 GHz. |
| Author(s): | M. K. Banafaa, M. H. Jamaluddin, S. H. Dahlan, A. A. Althuwayb |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 4 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1466 KB |
| Title: | Millimeter-wave Channel Measurement and Spatial Characteristics for Indoor Environments |
| File Type: | Conference Paper |
| Issue: | Volume: 2-4-E Antennas and Assessment for 5G Applications Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 2243 KB |
| Title: | Measurement of Temperature Dependence Complex Permittivity Based on Fitting Algorithm of Terminal Short Circuit |
| File Type: | Conference Paper |
| Issue: | Volume: 11-WA-3 Wave Interaction with Complex Media Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 310 KB |
| Title: | Macro-Modeling of the Defected Ground Structure by the Rational Function Fitting |
| File Type: | Conference Paper |
| Issue: | Volume: Macromodeling for EMC and SI Complex Systems Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 310 KB |
| Title: | Introduction of statistical priors into the D-bar method for electrical impedance tomography |
| File Type: | Conference Paper |
| Issue: | Volume: S18 Advances in Electrical Impedance Tomography Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 3350 KB |
| Title: | Internal Network Boundary Condition Incorporated in FDTD to Efficiently Modeling Low-profile Periodic Structure |
| File Type: | Conference Paper |
| Issue: | Volume: 4-3-A Advances in FDTD Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 517 KB |
| Title: | Influence on Aircraft Dynamic RCS Statistical Characteristics from Flight Speed |
| File Type: | Conference Paper |
| Issue: | Volume: 4-P4-A Electromagnetic Thoery and Computational Methods Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 395 KB |
| Title: | Improved High-Order Rational Approximation by Combining Rational Interpolation with the Vector Fitting Method |
| File Type: | Conference Paper |
| Issue: | Volume: Black Box Modeling Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 143 KB |
| Title: | Impact of the Mobile Phone Dimensions on the Hearing Aids Compatibility |
| Abstract: | In this work, we have investigated the influence of the mobile phone physical dimensions on the hearing aids compatibility (HAC). In our study, we have considered an inverted F antenna (IFA) and a planar inverted F antenna (PIFA) both fitting into a typical candy bar mobile phone. We have used a generic cubical head model to investigate the user impact on the near fields (NF). The field values are obtained by using the finite difference time domain (FDTD) method. We have observed significant difference in the peak field values between free space and with the head included although only free space values are specified in the relevant standard. Important outcome for the physical dimensions of the mobile phone is that the increase of the length of the handset significantly decreases the peak H value. |
| Author(s): | I. B. Bonev, O. Franek, M. Christensen, G. F. Pedersen |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 11 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 239 KB |
| Title: | Impact of an Antenna Scan Pattern on Surface Estimation for Radar-Based Breast Cancer Detection |
| File Type: | Conference Paper |
| Issue: | Volume: Microwave Imaging and Inverse Problems Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 720 KB |
| Title: | Impact Evaluation of an External Point Source to a Generalized Model of the Human Neck |
| File Type: | Conference Paper |
| Issue: | Volume: S04 Biomedical Applications - I Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 1980 KB |
| Title: | HPC for Legacy EM Code, a Mixed Language Approach using CUDA |
| File Type: | Conference Paper |
| Issue: | Volume: GPU for CEM Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 144 KB |
| Title: | HIPERCONE FDTD: Vectorized Highly Scalable Full-Wave Electromagnetic Solver |
| File Type: | Conference Paper |
| Issue: | Volume: S56 Parallel and GPU EM Computations Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 593 KB |
| Title: | Higher Order Spatial Operators for the Finite Integration Theory |
| Abstract: | The Finite Integration Technique (FIT) according to T. Weiland is an efficient and universal method for solving a large scale of problems in computational electrodynamics. Up to now the conventional formulation itself has had an accuracy order of two with respect to the spatial discretization. In this paper an innovative extension to fourth or even higher order is presented. The convergence of the presented scheme is demonstrated by a general dispersion equation and stability issues are discussed. An approach for a stable spatial interface connecting regions of higher order with the standard FIT scheme is proposed. |
| Author(s): | Holger Spachmann, Rolf Schuhmann, Thomas Weiland, Holger Spachmann, Rolf Schuhmann, Thomas Weiland |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 1 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 2009 KB |
| Title: | Higher Order Modes Analysis of a HEMP Simulator Using Time-Domain Simulation and Singular Value Decomposition |
| File Type: | Conference Paper |
| Issue: | Volume: 9-P-2 Poster Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 377 KB |
| Title: | High-Directive Dielectric Resonator Antenna over Curved Ground Plane Using Metamaterials |
| File Type: | Conference Paper |
| Issue: | Volume: Numerical Techniques for Electromagnetic Applications Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 181 KB |
| Title: | High Speed Data Communications based on W-band Automotive Radar MMIC |
| File Type: | Conference Paper |
| Issue: | Volume: Special Session: Technology for Emerging Commercial Millimeter-Wave Application Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 1085 KB |
| Title: | GPU-Accelerated Thin Wire Computations Coupled to DGFEM Electromagnetic Field Formulations |
| File Type: | Conference Paper |
| Issue: | Volume: Parallel and Hardware Acceleration for Computational Electromagnetics Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 736 KB |
| Title: | Generalized Finite Difference Method for Solving Waveguide Eigenvalue Problems |
| Abstract: | The generalized finite difference method (GFDM) is a meshless method that has become popular in recent years. The basic theory underlying GFDM is to expand the point cluster function value at the center node by Taylor’s formula and then obtain the best linear combinations of these function values to represent the derivative at the central node by the least square fitting technique. Subsequently, the minimized weighted error between the approximated value and the accurate value is obtained. This paper establishes the general steps for solving waveguide eigenvalue problems with GFDM. Excellent performance is shown by comparing the proposed method and other common solutions. The robustness of the proposed method is verified by calculating the cutoff wavenumbers of typical waveguides and the eccentric circular waveguide in different modes. |
| Author(s): | H. Xu, Y. Bao |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 3 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 501 KB |
| Title: | FVTD Simulations of Nano-structured Plasmonic Metamaterials |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling Techniques for Periodic Structures and Metamaterial Applications - I Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 349 KB |
| Title: | Focused Antenna Arrays for Wireless Power Transfer Application |
| File Type: | Conference Paper |
| Issue: | Volume: S46 Wireless Energy Harvesting and Power Transfer Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 516 KB |
| Title: | FIT Modeling of Injection Probes for Bulk Current Injection |
| File Type: | Conference Paper |
| Issue: | Volume: CST Modeling and Analysis Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 291 KB |
| Title: | Feasibility Analysis of the Installation of a Guided-Wave HEMP Simulator in an Electromagnetic Shielding Room |
| Abstract: | Field strength, waveform and uniformity are crucial to the validity of high-altitude electromagnetic pulse (HEMP) radiation sensitivity test (RS05/RS105) for large transient field facilities which are placed in expensive semi-anechoic chambers (SAC) usually. In this paper, we present a type of space requirements of those large transient field facilities installations in cheaper electromagnetic shielding room (ESR) by quantitative simulation analysis of the crucial factors. The field uniformity and the accuracy of guided-wave EMP simulator (GWES) in a SAC are verified by numerical cases and experiments. Time domain finite integral method (FIT) is employed to compute field data and singular value decomposition (SVD) technique has been used to extract the higher order modes (HOM). Based on the validated model, feasibility of GWES installation in an ESR was analyzed. The minimum space requirement of GWES installation has been obtained through optimization. |
| Author(s): | Y. Li, D. Su, S. Cui, W. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 6 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1497 KB |
| Title: | FDTD Simulations of Modulated Metasurfaces with Arbitrarily Shaped Meta-atoms by Surface Impedance Boundary Condition |
| Abstract: | In this paper, we propose a reducedcomplexity finite difference time domain (FDTD) simulations of modulated metasurfaces with arbitrary unit cells. The three dimensional (3D) physical structure of the metasurface is substituted by a spatially varying surface impedance boundary condition (IBC) in the simulation; as the mesh size is not dictated by sub-wavelength details, considerable advantage in space- and time-step is achieved. The local parameters of the IBC are obtained by numerical simulation of the individual unit cells of the physical structure, in a periodic environment approximation, in the frequency domain. As the FDTD requires an appropriate time domain impulse-response, the latter is obtained by broad-band frequency simulations, and vector fitting to an analytic realizable time response. The approach is tested on metasurface structures with complex unit cells and extending over 10 × 10 wavelengths, using a standard PC with 64GB RAM. |
| Author(s): | Y. Hu, Q. Zhou, X. Fang, M. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1008 KB |
| Title: | FDTD Evaluation of LEMP Considering the Lossy Dispersive Ground |
| Abstract: | An accurate evaluation of lightning electromagnetic pulse (LEMP) using the finite-difference time-domain (FDTD) method in 2-D cylindrical coordinates is studied, which takes the soil dispersion into account. The parameters of engineering soil models are reformed by the vector-fitting (VF) scheme, for an efficient handling in FDTD. The FDTD updating equations for the dispersive soil are developed with the semi-analytical recursive convolution (SARC) algorithm. The cylindrical CPML is also developed for truncating the dispersive soil. The efficiency of the proposed method is validated by comparing the numerical results with the Cooray-Rubinstein (CR) approximation. The proposed method provides an accurate FDTD evaluation of LEMP considering the soil dispersion and can be further incorporated into the simulations of more complicated LEMP problems. |
| Author(s): | Z. Sun, L. Shi, Y. Zhou, B. Yang, W. Jiang |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 1 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1840 KB |
| Title: | Fast Time Domain Integral Equation Solver for Dispersive Media with Auxiliary Green Functions |
| File Type: | Conference Paper |
| Issue: | Volume: Fast and Efficient CEM Methods Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 204 KB |
| Title: | Fast Design of Jerusalem-Cross Parameters by Equivalent Circuit Model and Least-Square Curve Fitting Technique |
| Abstract: | Based on an equivalent circuit model, the least-square curve fitting technique is proposed to quickly design optimum values of geometrical parameters of a dual-band Jerusalem-cross element for arbitrarily specifying any dual resonant frequencies. The validity of the least-square curve fitting technique is checked by comparing geometrical parameters and dual resonant frequencies of six Jerusalem-cross grids obtained by the proposed technique with those obtained by the improved empirical model and measurement method. Design of dual-band Jerusalem-cross slots is also conducted by the proposed technique. Simulation results of reflection and dual resonant frequencies of Jerusalem-cross slots designed by the proposed technique are also validated by measurement data. |
| Author(s): | H.-Y. Chen, T.-H. Lin, P.-K. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1859 KB |
| Title: | Evolutionary Design of a Wide Band Wire Antenna for WLAN and Wi-Fi Applications |
| File Type: | Conference Paper |
| Issue: | Volume: EM – Simulation – Driven Design: Modeling and Optimization Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 0 KB |
| Title: | Evolutionary Design of a Wide Band Wire Antenna for WLAN and Wi-Fi Applications |
| File Type: | Conference Paper |
| Issue: | Volume: EM – Simulation – Driven Design: Modeling and Optimization Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 439 KB |
| Title: | Evolutionary Design of a Wide Band Flat Wire Antenna for WLAN and Wi-Fi Applications |
| Abstract: | This paper presents a wire antenna for multi-band WLAN application, having a very simple geometry, designed using the StructureBased Evolutionary Programming; an innovative antenna design technique, based on evolutionary programming. The chosen fitness function includes far-field requirements, as well as wideband input matching specifications. The latter requirements, which must be present in every useful antenna design, allow to stabilize the algorithm and to design both optimal and robust antennas. The antenna has been analysed with NEC-2 during the evolutionary process and the outcome of the procedure shows a very good performance; with a -10dB bandwidth that covers the required frequencies for multi-band WLAN applications (2.4/5.2/5.8 GHz) and beyond, and an end-fire gain greater than 10 dB. The NEC-2 results have been also compared to the ones obtained by a well-assessed, general purpose, 3D electromagnetic software, HFSS by Ansys, showing a very good agreement. |
| Author(s): | G. A. Casula, G. Montisci, A. Fanti, P. Maxia, G. Mazzarella |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 7 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 791 KB |
| Title: | Errors in FDTD, FIT and FVTD |
| File Type: | Conference Paper |
| Issue: | Volume: Time Domain Numerical Modeling Beyond FDTD Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 208 KB |
| Title: | Equivalent Circuit Approximation to the Connector-Line Transition at High Frequencies using Two Microstrip Lines and Data Fitting |
| Abstract: | This article presents a method of obtaining an equivalent lumped element circuit to model the electrical connector-line transitions in the ultra-high frequency (UHF) band. First, the scattering matrices of two microstrip transmission lines that are otherwise identical but have the physical lengths of d and 2d are measured. Next, the theoretical model of the lines cascaded with the connector-line transitions modeled as lumped element circuits is established. The selection of the line lengths to be d and 2d results in an over determined system of equations that links the circuit component values to the two-port network parameters of the cascaded system. Finally, the least-squares data fitting procedure yields the best-fit component values. The results show that in our tested scenario, 3-component reactive circuit models well the transitions. Compared with the previous methods, the proposed approach does not require knowledge of the dielectric properties of the substrate of the measured transmission lines. This property integrates the method with our previous work on estimating a microstrip line substrate’s relative permittivity and loss tangent. The obtained transition circuit model is also validated through the testing of two quarter-wave transformers. The lines and transformers are implemented on a textile substrate to highlight the method’s applicability to wearable textile-based electronics. |
| Author(s): | D. Le, N. Pournoori, L. Sydanheimo , L. Ukkonen, T. Bjorninen |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 822 KB |
| Title: | Enhanced Artificial Immune System Algorithm and Its Comparison to Bio-Inspired Optimization Techniques for Electromagnetics Applications |
| Abstract: | This paper introduces an enhanced artificial immune system algorithm (EAIS) that benefits from a hybrid approach by integrating concepts from the genetic algorithm (GA) and particle swarm optimization (PSO). The potential of the EAIS algorithm is demonstrated by comparing its performance with other bio-inspired optimization algorithms; namely the particle swarm optimization (PSO) and the conventional artificial immune system (AIS) when applied to two electromagnetics applications, such as the design of antireflective surfaces, and microstrip electromagnetic band gap (EBG) structures. |
| Author(s): | O. Kilic, Q. M. Nguyen |
| File Type: | Express Journal Paper |
| Issue: | Volume: 1 Number: 3 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 3129 KB |
| Title: | Enhanced Artificial Immune System Algorithm and Its Comparison to Bio-Inspired Optimization Techniques for Electromagnetics Applications |
| Abstract: | This paper introduces an enhanced artificial immune system algorithm (EAIS) that benefits from a hybrid approach by integrating concepts from the genetic algorithm (GA) and particle swarm optimization (PSO). The potential of the EAIS algorithm is demonstrated by comparing its performance with other bio-inspired optimization algorithms; namely the particle swarm optimization (PSO) and the conventional artificial immune system (AIS) when applied to two electromagnetics applications, such as the design of antireflective surfaces, and microstrip electromagnetic band gap (EBG) structures. |
| Author(s): | O. Kilic, Q. M. Nguyen |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1661 KB |
| Title: | Enhanced Artificial Immune System Algorithm and Its Comparison to Bio-Inspired Optimization Techniques for Electromagnetics Applications |
| Abstract: | This paper introduces an enhanced artificial immune system algorithm (EAIS) that benefits from a hybrid approach by integrating concepts from the genetic algorithm (GA) and particle swarm optimization (PSO). The potential of the EAIS algorithm is demonstrated by comparing its performance with other bio-inspired optimization algorithms; namely the particle swarm optimization (PSO) and the conventional artificial immune system (AIS) when applied to two electromagnetics applications, such as the design of antireflective surfaces, and microstrip electromagnetic band gap (EBG) structures. |
| Author(s): | O. Kilic, Q. M. Nguyen |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1661 KB |
| Title: | Empirical / Ray-tracing Hybrid Approach for COST 231 Unknown Building Layouts |
| File Type: | Conference Paper |
| Issue: | Volume: EM Simulation Using Wireless InSite Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 289 KB |
| Title: | Electromagnetic analysis use cases with CST MicroWave Studio |
| File Type: | Conference Paper |
| Issue: | Volume: CST Modeling and Analysis Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 191 KB |
| Title: | EFFICIENT SOLUTION OF LINEAR SYSTEMS IN MICROWAVE NUMERICAL METHODS |
| Abstract: | A common bottle-neck, limiting the performance of many electromagnetic numerical methods, is the solution of sparse linear systems. Until now, this task has been typically solved by using iterative sparse solvers, whose require heavy computational efforts, especially when the problem is not well conditioned. An alternative strategy is based on the use of banded solvers, which numerical complexity is quadratical with respect to the matrix bandwidth. Of course, these methods are efficient provided that the matrix bandwidth is sufficiently small. In this paper, a method (called WBRA) for the bandwith reduction of a sparse matrix is presented: it is here specifically customized to typical electromagnetic matrices. The approach is superior to all the previous algorithims, also with respect to commercial well-known packages, and is suitable also for non-symmetric problems. As demonstrated by results, the use of WBRA, in conjuction with common banded solvers, substantially improves (up to one order of magnitude) the solution times in several electromagnetic approaches, such as Mode-matching, FEM, and MoM analysis of microwave circuits. In conclusion, it is proved that the high efficiency and effectiveness of WBRA turns the stragety of bandwith reduction combined with a banded solver into the most profitable way of solving linear systems in electromagnetic numerical methods. |
| Author(s): | L. Tarricone, F. Malucelli, A. Esposito, L. Tarricone, F. Malucelli, A. Esposito |
| File Type: | Journal Paper |
| Issue: | Volume: 14 Number: 3 Year: 1999 |
| Download Link: | Click here to download PDF File Size: 625 KB |
| Title: | Efficient numerical analysis of arrays of identical elements with complex shapes |
| Abstract: | A fast method-of-moments approach is proposed for the solution of finite arrays of complex identical elements, involving both metal and finite dielectric parts. The method is based on the use of Macro Basis Functions (MBF), also named “Characteristic” Basis Functions, among which interactions are computed very fast with the help of a Multipole approach. Fast evaluation of array patterns or embedded element patterns is obtained through decomposition into a finite series of pattern multiplication problems. Examples are provided for finite arrays of bowtie antennas embedded in dielectric boxes. For periodic arrays, results are compared with infinite-array solutions. The method is also extended to non-periodic structures, for which the Multipole approach appears very useful for interactions outside the near-field region. We show that interactions in the near-field region can benefit from an interpolation procedure. |
| Author(s): | C. Craeye, D. González-Ovejero, X. Dardenne |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 2 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 468 KB |
| Title: | Efficient Modeling of Towel Bar Antennas Using Model of Distributed Loading along Wires |
| Abstract: | This paper presents an efficient technique to determine equivalents of towel bar antenna dielectric standoffs in the form of wires with distributed loadings using WIPL-D Pro (3-D EM solver) software. Starting from the product, we will determine its basic characteristics and propose simplifications in modeling for further analysis. Benefits of this technique are simplicity of modeling and fast, but still accurate, simulations. |
| Author(s): | M. M. Jovicic, S. N. Tabet, B. M. Kolundzija |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 2 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1531 KB |
| Title: | Efficient Modeling of Towel Bar Antennas Using Model of Distributed Loading Along Wires |
| File Type: | Conference Paper |
| Issue: | Volume: S37 Advances in Electromagnetic Modeling by WIPL-D I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 613 KB |
| Title: | Effective Modeling of Tunable Graphene with Dispersive FDTD - GSTC Method |
| Abstract: | We propose an effective method of dispersive finite difference time domain-generalized sheet transition conditions (FDTD-GSTCs) for the modeling of electromagnetic fields from tunable graphene with nearly zero thickness. To model the tunable graphene effectively, the susceptibilities are introduced instead of its physical structure, which can be extracted from reflection or transmission coefficients. In order to model the graphene in broadband, a dispersive FDTD-GSTC method is introduced by fitting the susceptibilities with respect to frequencies with the complex-conjugate poleresidue (CCPR) pairs. Numerical results demonstrate the validity of the proposed method. |
| Author(s): | X. Du, H. Yu, M. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 6 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2104 KB |
| Title: | Dual-Band Microstrip Antenna for the Fifth Generation Indoor / Outdoor Wireless Applications |
| File Type: | Conference Paper |
| Issue: | Volume: S05 Microwave/Millimeter Wave and Terahertz Devices and Applications I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 300 KB |
| Title: | Dual-Band 4-Way Wilkinson Power Divider Based on Improved Simplified Composite Right and Left Handed Transmission Lines |
| Abstract: | In this paper, by using improved simplified composite right and left handed transmission lines (I-S-CRLH-TL), a novel 4-way parallel Wilkinson power divider (WPD) is presented. The proposed WPD exhibits the benefits of excellent isolation and equal power split between output ports in the dual frequency band. Also, the dual-band nature of this divider, low cost and easy integration with printed circuits and printed antennas in a compact size makes this device a very good candidate for feeding dual-band antennas and microwave devices. The proposed divider is designed and fabricated on a low cost substrate with permittivity of 4.4 and thickness of 0.79 mm to work at two arbitrary frequency bands of 0.95 GHz and 2.43 GHz. There is a good agreement between simulated and measured results in all cases. The design concept of this paper can be easily extended to another type of dual-band microwave components. |
| Author(s): | H. Younesiraad, M. Bemani |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 1 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 614 KB |
| Title: | Driving and Extending Legacy Codes using Python |
| File Type: | Conference Paper |
| Issue: | Volume: Object Oriented Computational Electromagnetics Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 81 KB |
| Title: | Discretized Aperture Integration, Surface Integration Analysis of Airborne Radomes |
| Abstract: | Full-wave electromagnetic methods are becoming increasingly more viable for the design and analysis of airborne radomes; however, there still exist many applications that require the speed associated with high frequency approximation methods. Presented here are accuracy improvements to the aperture integration surface integration (AiSi) method by incorporating both aperture and radome discretization into smaller groups in advance of the propagation routines, herein referred to as discretized radome discretized aperture integration surface integration (DrDaiSi). Dyadic Green’s functions are utilized to determine exact field vectors from source current vectors. The capabilities of DrDaiSi are welltested for typical airborne radomes, and a case study is presented which includes a 2:1 fineness ratio tangent ogive radome with dielectric constant of 7 and a metallic tip. The benefits of the DrDaiSi algorithm over a nondiscretized AiSi method for predicting radome loss, boresight error, and radiation pattern degradation are demonstrated. Results are compared to a full-wave solution of the antenna and radome problem that was solved in CST to represent “truth.” Transmission loss agreement is achieved to within 0.4 dB or better, and boresight error agreement is achieved to within 0.2 deg. or better in both elevation and azimuth scan planes for a severely detuned radome. |
| Author(s): | J. W. Jordan, B. L. Cannon |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 3 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 461 KB |
| Title: | Development of a Parallel Scene Generation Electromagnetic Modeling Tool |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling Using WIPL-D Code(II) Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 0 KB |
| Title: | Development of a Parallel Scene Generation Electromagnetic Modeling Tool |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling Using WIPL-D Code(II) Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 131 KB |
| Title: | Design of Shaped Multibeam Reflector Antenna Based on Cognitive Behavior Optimization Algorithm |
| File Type: | Conference Paper |
| Issue: | Volume: 11-WA-3 Wave Interaction with Complex Media Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 560 KB |
| Title: | Design of Low-Cost, Circularly Polarized, and Wideband U-Slot Microstrip Patch Antenna with Parasitic Elements for WiGig and WPAN Applications |
| Abstract: | In this article, a well matched U-Slot Microstrip Patch Antenna (MPA) with two paratactic elements is designed and simulated. The antenna is designed to resonate at 60 GHz (V-band) and exhibits a wideband extend from 53.3 GHz to 60.8 GHz with more than 87% total efficiency. The presence of U-slot makes a current perturbation in the antenna which contributes to generate a Circular Polarization (CP). The 3-dB Axial Ratio (AR) is extended from 56 – 57.2 GHz (~ 1.2 GHz bandwidth). The analysis and optimization processes throughout this paper are carried out using Finite Element Method (FEM) and verified with Finite Integration Technique (FIT). Good agreement between the results by the two simulators is obtained. Hence, the performance of the proposed antenna makes it a good candidate for fifth generation applications at V-band like Wireless Gigabit Alliance (WiGig) and Wireless Personal Area Network (WPAN). |
| Author(s): | M. S. Ibrahim |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 9 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1412 KB |
| Title: | Design of Low-Cost, Circularly Polarized, and Wideband U-Slot Microstrip Patch Antenna with Parasitic Elements for WiGig and WPAN Applications |
| Abstract: | In this article, a well matched U-Slot Microstrip Patch Antenna (MPA) with two paratactic elements is designed and simulated. The antenna is designed to resonate at 60 GHz (V-band) and exhibits a wideband extend from 53.3 GHz to 60.8 GHz with more than 87% total efficiency. The presence of U-slot makes a current perturbation in the antenna which contributes to generate a Circular Polarization (CP). The 3-dB Axial Ratio (AR) is extended from 56 – 57.2 GHz (~ 1.2 GHz bandwidth). The analysis and optimization processes throughout this paper are carried out using Finite Element Method (FEM) and verified with Finite Integration Technique (FIT). Good agreement between the results by the two simulators is obtained. Hence, the performance of the proposed antenna makes it a good candidate for fifth generation applications at V-band like Wireless Gigabit Alliance (WiGig) and Wireless Personal Area Network (WPAN). |
| Author(s): | M. S. Ibrahim |
| File Type: | Express Journal Paper |
| Issue: | Volume: 34 Number: 9 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1412 KB |
| Title: | Design of Chiral 4-Tiered Wireless Power Transfer (WPT) Systems for Vertiports |
| File Type: | Conference Paper |
| Issue: | Volume: S30 Energy Harvesting Applications Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 281 KB |
| Title: | Design of a Wearable Microwave Antenna System for Breast Tumor Imaging |
| File Type: | Conference Paper |
| Issue: | Volume: S38 EM Modeling and Applications - I Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 630 KB |
| Title: | Design of a Novel Dual-Band, Electrically Small, Printed Octafilar Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: S33 Antenna Systems and Applications Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 280 KB |
| Title: | Design and Implementation of Multiband Metamaterial Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: S16 Metamaterial, Devices, and Antenna Applications Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 301 KB |
| Title: | Design and Analysis of an Interior Continuous Magnetic Gear Box Using Finite Element Method |
| Abstract: | Magnetic gears offer important potential benefits compared with mechanical gears such as reduced maintenance, improved reliability, inherent overload protection, and physical isolation between the input and output shafts. This paper presents the design and analysis of a novel structure of magnet gear, which named Interior Magnetic Gear (IMG) using neodymium-iron-boron magnets for the applications in which continuous ratio of gear box is useful such as wind generators, electric vehicles and etc. The analysis is performed by Finite Element Method (FEM) to predict output torque, speed and magnetic field distribution inside the gear box. The IMG made up of an inner rotor and an outer rotor. The inner rotor is similar to the rotor of a 3 phase wound rotor induction motor and the outer rotor consists of 6 PM poles. Both the inner rotor and the outer rotor can be employed as a low/high speed rotating part. The interior arrangement of PMs result many advantage such as low torque ripple. The simulation and analytical results are in good accord. |
| Author(s): | B. Majidi, J. Milimonfared |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 1 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 570 KB |
| Title: | Debye Parameters of Humidity-Varying Soils for Induction Logging Techniques |
| Abstract: | This paper focuses on the tabulation of calculated Debye coefficients for a wide range of soils for source waves ranging from 300 MHz to 2 GHz. Debye coefficients of different soils will produce accurate FDTD dispersive simulations for wireline logging purposes. The FDTD dispersion analysis is based on an Auxiliary Differential Equation (ADE) method which depends on the Debye coefficients. A complex set of soil data is acquired and used in a twostep numerical solver to calculate the Debye coefficients. For a wide range of soils, Debye coefficients were developed for one, two, and three pole expansions. Most fits for one pole fits were highly inaccurate, so the coefficients generated were disregarded. Coefficients for two and three term expansions were accurate and were generated and tabulated here. |
| Author(s): | A. Velasco, A. Z. Elsherbeni, J. E. Diener, M. F. Hadi |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 9 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1335 KB |
| Title: | Debye Constants for Biological Tissues From 30 Hz to 20 GHz |
| Abstract: | Debye modeling for the dielectric properties of dispersive materials facilities its incorporation into the FDTD formulation. This paper generates a comprehensive list of multi-term Debye coefficients for 16 biological tissues. A numerical technique is developed to accurately fit one, two, and three-term Debye equations with the published experimental data of biological tissues. Using the generated coefficients, the reconstructed complex permittivity is shown to be in excellent agreement with the corresponding measured data over the frequency rang 30 Hz to 20 GHz. |
| Author(s): | Mohamed A. Eleiwa, Atef Z. Elsherbeni, Mohamed A. Eleiwa, Atef Z. Elsherbeni |
| File Type: | Journal Paper |
| Issue: | Volume: 16 Number: 3 Year: 2001 |
| Download Link: | Click here to download PDF File Size: 758 KB |
| Title: | Curved Dual- Band Dielectric Resonator Tag Antenna for RFID Applications |
| File Type: | Conference Paper |
| Issue: | Volume: Dielectric Resonator Antennas Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 340 KB |
| Title: | Cross Polarized 2x2 LTE MIMO System for Automotive Shark Fin Application |
| Abstract: | In this research we propose two orthogonally placed FR4 printed planar monopole antenna elements for use in the automobile roof top shark fin antenna for LTE MIMO applications. The discussed MIMO antenna system is designed to cover the worldwide LTE frequency band from 698MHz to 2700MHz. The goal of this research is to achieve satisfactory MIMO performance across the whole band while staying within physical constraints of the shark fin style antenna. The target reflection coefficient (S11) of each element is -6dB. Because of physical constraints of the automotive shark fin design antenna MIMO decorrelation is achieved by cross polarization and small distance separation. Correlation better than -12dB is targeted and achieved in higher bands, while in lower frequency bands antennas would not benefit from MIMO performance. Numerical simulation of the MIMO antenna system is performed using FEKO in order to verify the design parameters. Simulation findings are confirmed by manufacturing antennas and testing in the lab. |
| Author(s): | D. Preradovic, D. N. Aloi |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 10 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1455 KB |
| Title: | Crack Detection Using a Level-set Technique and Thin Shapes |
| File Type: | Conference Paper |
| Issue: | Volume: Detection and Imaging: Theoretical, Algorithmic, Technology and System Advances Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 60 KB |
| Title: | Coupled-mode Analysis for Modal Birefringence of High-order Modes in Geometry-perturbed Fibers |
| File Type: | Conference Paper |
| Issue: | Volume: 2-2-A Multiphysics Modeling and Simulation Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 383 KB |
| Title: | COMPUTATIONAL SIMULATION OF ELECTRIC FIELDS SURROUNDING POWER TRANSMISSION AND DISTRIBUTION LINES |
| Abstract: | A numerical technique is presented for computing the potential distributions surrounding power transmission and distribuhon lines of complex geometry. The technique employs a finite difference solution using boundary-fitted coordinates. A newly developed finite difference solver code is coupled with the existing EAGLE grid generation code to yield a system capable of solving for the electric potential andfield distributions surrounding complex configurations. A code validation example is presented which consists of a sphere-to-ground electrostatic solution. Sample results are also presented for a distribution line model. [Vol. 8, No. 2 (1993), pp 4-16] |
| Author(s): | J. Patrick Donohoe*, Min-Yee Jiang**, Joe F. Thompson**, David B. Miller*, J. Patrick Donohoe*, Min-Yee Jiang**, Joe F. Thompson**, David B. Miller* |
| File Type: | Journal Paper |
| Issue: | Volume: 8 Number: 2 Year: 1993 |
| Download Link: | Click here to download PDF File Size: 763 KB |
| Title: | Comparison Between Genetic and Particle Swarm Optimization Algorithms in Optimizing Ships’ Degaussing Coil Currents |
| Abstract: | This paper presents a comparison between two well-known evolutionary algorithms in optimization of the degaussing coils currents of a ship which are used to reduce the magnetic anomalies of the ferromagnetic hull of the ships induced by the Earth’s magnetic field. To achieve this, first the magnetic anomalies of a simple model of a ship and the effect of each degaussing coil are simulated by using 3D finite element analysis (FEA) software. Then, both genetic algorithm and particle swarm optimization are used to find the best fitting coil currents which can reduce the anomalies of the ship. Using these algorithms is much simpler than optimizing this problem in FEA software in which a huge amount of numerical analyses are needed. This comparison will show which of these algorithms works better in this specific problem. |
| Author(s): | S. M. Makouie, A. Ghorbani |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 5 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1269 KB |
| Title: | Compact Bandpass Filter with Sharp Out-of-band Rejection and its Application |
| Abstract: | A novel compact bandpass filter considered as the harmonic suppression circuit is designed in this paper. Because of the application of a T-shaped structure, the filter is improved in performance and reduced in size. Two transmission zeros at passband edge can be conveniently adjusted by changing the length of the open stubs located at the center of the T-shaped structure. Two filters with different open-stub structures are designed. Good agreement between the simulation and the measurement is acquired, which verifies the theoretical predictions. Benefiting from this feature, an active frequency multiplier with the proposed filter as the output matching network is designed. When input signal is set to be 6 dBm, output power of the second harmonic varies from 6 to 8 dBm with 20 dBc suppression for the first, third and fourth harmonics. |
| Author(s): | L. Zhou, Y.Z. Yin, W. Hu, X. Yang |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 3 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1807 KB |
| Title: | Compact Antenna Designs for Wearable and Portable Medical System |
| Abstract: | A button wearable antenna and an Lshape planar inverted F antenna (PIFA) antenna were designed for medical eHealth system. A spiral top button wearable antenna was implemented into the antenna structure to obtain additional inductance. Both simulated and measured reflection coefficients show it can cover both the 2.4-2.5GHz and 5.15- 5.825 GHz ISM bands. Good omnidirectionality was achieved at x-y plane for all three bands. A compact L-shape PIFA antenna was designed and fabricated for laptop wireless local area network (WLAN) application to communicate with wearable antenna. The antenna was formed to L-shape to minimize the ground plane size, so that it can be fitted into the top corners of a laptop display. The effect of the presence of display panel was discussed. |
| Author(s): | W. Huang, A. A. Kishk |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 4 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 1166 KB |
| Title: | Combining data-fitting and signal processing for efficient time-domain characterization of aperture antennas |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Advances in Time Domain Modeling Techniques Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 228 KB |
| Title: | Circuit Modelling Methodology for Dual-band Planar Antennas |
| Abstract: | This paper presents a simple and systematic approach to determine the equivalent frequencyindependent circuit model for a dual-band planar antenna. The Foster Canonical network synthesis technique with two RLC tanks has been employed to generate the two resonant bands of the antenna. The transfer function model is subsequently refined using a data fitting algorithm (viz the Nelder-Mead simplex algorithm). Parametric adjustments are performed at the final stage in order to further improve the accuracy of the final parameters. |
| Author(s): | K. H. Yeap, T. Meister, Z. X. Oh, H. Nisar |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2097 KB |
| Title: | CIRCLE-FIT SUMMATION ACCELERATION OF PERIODIC GREEN’S FUNCTIONS |
| Abstract: | The circle-fit algorithm is shown to be an attractive alternative to the spectral domain form of the two-dimensional periodic Green’s function when the radiated fields are evaluated in the plane of the array. As the name implies, the circle-fit algorithm predicts the summation limit by fitting circles to the converging spiral of spatial domain partial sums in the complex plane. Several numerical examples comparing the raw spatial, spectral, and circle-fit accelerated spatial sums demonstrate the algorithm's computational savings. While other series extrapolation methods are shown to be more efficient, the circle-fit algorithm has the advantage of providing insight into how the Green’s function converges. |
| Author(s): | Peter J. Collins, Peter J. Collins |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 1 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 185 KB |
| Title: | Chipless Graphene Tag and Dual-CP Reader for Internet of Things |
| File Type: | Conference Paper |
| Issue: | Volume: 3-3-C Microwave Components Based on Emerging Processes and Materials Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 824 KB |
| Title: | Characterization of Atmospheric Absorption in the 60 GHz Frequency Band Using a Multi-Pole Material Model |
| Abstract: | Atmospheric attenuation of electromagnetic signals at the 60 GHz frequency band is dominated by oxygen absorption which represents a major obstacle to 5G communications using this band. So far, only empirical equations that fit the experimental absorption data have been reported. These empirical models are not suitable to employ in standard full-wave electromagnetic simulators based on the numerical solution of Maxwell’s equations. In this paper, a frequency-dependent material model for atmospheric absorption at the 60 GHz band is presented. Further, a numerical simulator that incorporates this multi-pole material dispersion model and uses the rotating boundary conditions to allow for long propagation distances is developed. The simulation algorithm is based on the auxiliary differential equation finite-difference time-domain (ADE-FDTD) technique which implements the general electric polarization formulation. The results are useful in the prediction of propagation power loss between line-of-sight communication links and in the planning and positioning of ground and air-borne facilities. |
| Author(s): | M. Arvas, E. Arvas, M. A. Alsunaidi |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 12 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2046 KB |
| Title: | Broadband Permittivity and Permeability Extraction of Ferrite Cores up to the GHz Range via Measurements and Simulations |
| Abstract: | In this contribution a method is presented which allows for the characterization of the magnetic (mu’-j mu’’) as well as the dielectric (epsilon’-j epsilon’’) properties of ferrites in a broad frequency band (kHz to GHz). In order to determine the material properties at certain frequencies, the simulation model parameters of a particular test setup are tuned via optimization such that the simulated response of a sample to an electromagnetic excitation matches to the measured one. A loop and parallel plate setup support a low frequency parameter extraction of the sample while a coplanar line is used for high frequencies. The extracted material properties are fitted by a broadband causal fit in order to obtain a material model for the whole frequency range. The presented method is verified for a setup with a coil and a ferrite core. The results show that dielectric properties of the ferrite core cannot be neglected for microwave frequencies. |
| Author(s): | C. Reinhold, P. Scholz, U. Jumar |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 7 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2466 KB |
| Title: | Broadband Permittivity and Permeability Extraction of Ferrite Cores up to the GHz Range via Measurements and Simulations |
| Abstract: | In this contribution a method is presented which allows for the characterization of the magnetic (mu’-j mu’’) as well as the dielectric (epsilon’-j epsilon’’) properties of ferrites in a broad frequency band (kHz to GHz). In order to determine the material properties at certain frequencies, the simulation model parameters of a particular test setup are tuned via optimization such that the simulated response of a sample to an electromagnetic excitation matches to the measured one. A loop and parallel plate setup support a low frequency parameter extraction of the sample while a coplanar line is used for high frequencies. The extracted material properties are fitted by a broadband causal fit in order to obtain a material model for the whole frequency range. The presented method is verified for a setup with a coil and a ferrite core. The results show that dielectric properties of the ferrite core cannot be neglected for microwave frequencies. |
| Author(s): | C. Reinhold, P. Scholz, U. Jumar |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 7 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2466 KB |
| Title: | Benefits and Challenges of GPU Accelerated Electromagnetic Solvers from a Commercial Point of View |
| Abstract: | This paper discusses the benefits but also challenges of GPU accelerated electromagnetic solvers from a commercial point of view, namely using FEKO as example. Specifically, the effects of some of the complex interdependencies between different components are presented. It is shown that despite the advances made in the field of GPGPU computing, and impressive speedups for parts of a program or simplified problems, there are a number of factors to consider before these techniques can be applied to a commercial product that is expected to be robust and, most importantly, to always give trustworthy results for a wide variety of problems. |
| Author(s): | U. Jakobus |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1591 KB |
| Title: | Benefits and Challenges of GPU Accelerated Electromagnetic Solvers from a Commercial Point of View |
| Abstract: | This paper discusses the benefits but also challenges of GPU accelerated electromagnetic solvers from a commercial point of view, namely using FEKO as example. Specifically, the effects of some of the complex interdependencies between different components are presented. It is shown that despite the advances made in the field of GPGPU computing, and impressive speedups for parts of a program or simplified problems, there are a number of factors to consider before these techniques can be applied to a commercial product that is expected to be robust and, most importantly, to always give trustworthy results for a wide variety of problems. |
| Author(s): | U. Jakobus |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 2 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1591 KB |
| Title: | Benefits and Challenges of GPU Accelerated Electromagnetic Solvers from a Commercial Point of View |
| Abstract: | This paper discusses the benefits but also challenges of GPU accelerated electromagnetic solvers from a commercial point of view, namely using FEKO as example. Specifically, the effects of some of the complex interdependencies between different components are presented. It is shown that despite the advances made in the field of GPGPU computing, and impressive speedups for parts of a program or simplified problems, there are a number of factors to consider before these techniques can be applied to a commercial product that is expected to be robust and, most importantly, to always give trustworthy results for a wide variety of problems. |
| Author(s): | U. Jakobus |
| File Type: | Express Journal Paper |
| Issue: | Volume: 1 Number: 4 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1572 KB |
| Title: | Benchmarking GPU Accelerated WIPL-D Out-of-Core Solver |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Simulation using Wipl-D Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 2301 KB |
| Title: | Assessment of ALEGRA Computation for Magnetostatic Configurations |
| Abstract: | A closed-form solution is described here for the equilibrium configurations of the magnetic field in a simple heterogeneous domain. This problem and its solution are used for rigorous assessment of the accuracy of the ALEGRA code in the quasistatic limit. By the equilibrium configuration we understand the static condition, or the stationary states without macroscopic current. The analysis includes quite a general class of 2D solutions for which a linear isotropic metallic matrix is placed inside a stationary magnetic field approaching a constant value ???????? ° at infinity. The process of evolution of the magnetic fields inside and outside the inclusion and the parameters for which the quasi-static approach provides for self-consistent results is also explored. It is demonstrated that under spatial mesh refinement, ALEGRA converges to the analytic solution for the interior of the inclusion at the expected rate, for both body-fitted and regular rectangular meshes. |
| Author(s): | M. Grinfeld, J. Niederhaus, A. Porwitzky |
| File Type: | Express Journal Paper |
| Issue: | Volume: 1 Number: 2 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 918 KB |
| Title: | Assessment of ALEGRA Computation for Magnetostatic Configurations |
| Abstract: | A closed-form solution is described here for the equilibrium configurations of the magnetic field in a simple heterogeneous domain. This problem and its solution are used for rigorous assessment of the accuracy of the ALEGRA code in the quasistatic limit. By the equilibrium configuration we understand the static condition, or the stationary states without macroscopic current. The analysis includes quite a general class of 2D solutions for which a linear isotropic metallic matrix is placed inside a stationary magnetic field approaching a constant value Hi° at infinity. The process of evolution of the magnetic fields inside and outside the inclusion and the parameters for which the quasi-static approach provides for self-consistent results is also explored. It is demonstrated that under spatial mesh refinement, ALEGRA converges to the analytic solution for the interior of the inclusion at the expected rate, for both body-fitted and regular rectangular meshes. |
| Author(s): | M. Grinfeld, J. Niederhaus, A. Porwitzky |
| File Type: | Express Journal Paper |
| Issue: | Volume: 33 Number: 1 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1614 KB |
| Title: | Assessment of ALEGRA Computation for Magnetostatic Configurations |
| Abstract: | A closed-form solution is described here for the equilibrium configurations of the magnetic field in a simple heterogeneous domain. This problem and its solution are used for rigorous assessment of the accuracy of the ALEGRA code in the quasistatic limit. By the equilibrium configuration we understand the static condition, or the stationary states without macroscopic current. The analysis includes quite a general class of 2D solutions for which a linear isotropic metallic matrix is placed inside a stationary magnetic field approaching a constant value Hi° at infinity. The process of evolution of the magnetic fields inside and outside the inclusion and the parameters for which the quasi-static approach provides for self-consistent results is also explored. It is demonstrated that under spatial mesh refinement, ALEGRA converges to the analytic solution for the interior of the inclusion at the expected rate, for both body-fitted and regular rectangular meshes. |
| Author(s): | M. Grinfeld, J. Niederhaus, A. Porwitzky |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 1 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1614 KB |
| Title: | Application of the Savant/WIPL-D Hybrid Solver to Analyze the Installed Performance of a Monopulse Antenna Array Mounted on a Widebody Aircraft |
| File Type: | Conference Paper |
| Issue: | Volume: EM Applications using WIPL-D Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 1058 KB |
| Title: | Antennas and RF Components Designed with Graded Index Composite Materials |
| File Type: | Conference Paper |
| Issue: | Volume: S22 Advances in Hybrid Material Additive Manufacturing of Antennas Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 261 KB |
| Title: | Analysis of Typical Ground Clutter Statistical Characteristics |
| File Type: | Conference Paper |
| Issue: | Volume: 3-P3-D Microwave Characterization and Measurement Techniques Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 432 KB |
| Title: | Analysis of the Scattering from Rough Surfaces with the C Method and the Short-Coupling Range Approximation |
| File Type: | Conference Paper |
| Issue: | Volume: Computational Electromagnetics for Photonics Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 303 KB |
| Title: | Analysis of Freshwater Curved and Flat Spiral Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: S24 Applied EM for Biomedical and IoT Radar Technologies Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 1163 KB |
| Title: | Analysis of a Physically and Electrically Large UHF Antenna Array Using WIPL-D |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Electromagnetic Modeling by WIPL-D Software Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 682 KB |
| Title: | Analysis of a Novel Ka Horn Antenna with Low Cross-Polarization |
| Abstract: | A Ka combined horn antenna with low cross-polarization is presented in this paper. The antenna consists of an edge-slotted waveguide linear array, a metallic-grid plane in the horn throat and a horn. The effects of metallic-grid and single-ridged waveguide to the cross-polarization are analyzed. Three kinds of 62-element Taylor linear array at Ka band are fabricated and measured and the measured cross-polarization level is less than -35dB in operating bandwidth. The proposed antennas are benefit for fabrication and fixation with low cross-polarization and can be extensively used in radar and communication systems. |
| Author(s): | Y. Z. Liu, S. Xiao, B. Z. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 11 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 1180 KB |
| Title: | An Unequal Wilkinson Power Divider using Half Mode Substrate Integrated Waveguide |
| Abstract: | A new unequal Wilkinson power divider is presented in this paper. The structure benefits from half mode substrate integrated waveguide (HMSIW). In order to increase the characteristic impedance of the HMSIW line, an inductive post is used in the line. Different dividing ratios are obtained by changing the diameter of the inductive post. The experimental results show that the power dividing ratio is 5.1:1 over the frequency range of 9.1 GHz to 12.8 GHz. The input and output ports are well-matched and the output ports are isolated from each other over this frequency range. The experimental results and simulation results of CST Microwave Studio are in good agreement. |
| Author(s): | Z. Mazani, G. Moradi |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 11 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 0 KB |
| Title: | An Ontology-based Decision Maker for Electromagnetic Problem Solving |
| File Type: | Conference Paper |
| Issue: | Volume: SEMCAD X: Recent Modeling Advances for Virtual Prototyping Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 394 KB |
| Title: | An Investigation of the Relationship between Effective Relative Permittivity and Infill Density in a 3D Printed Slab |
| Abstract: | This paper presents a simulation-based study on the relative permittivity of 3D printed dielectric slabs printed with varying infill densities. In this study, a percentage volumetric model has been employed to model the infill density in a 3D printed dielectric slab. The relative permittivity of the filament material used to design the slab is assumed to be 2.45. The modeled slab is fitted into various rectangular waveguides with varying dimensions corresponding to different frequency ranges. As the infill density decreases, the relative permittivity of the dielectric slabs decreases. This lower value of relative permittivity is referred to as effective relative permittivity (εr.eff) throughout the paper. The study concludes that the effective relative permittivity of the slab decreases linearly as the infill density is decreased for the model. This study offers valuable insights into the effective relative permittivity of dielectric slabs under varying infill densities, providing implications for applications in areas such as antenna design. |
| Author(s): | B. Kattel, W. E. Hutchcraft, R. K. Gordon |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 12 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 5671 KB |
| Title: | An Empirical Formula for Resonant Frequency Shift due to Jerusalem-Cross FSS with Substrate on One Side |
| Abstract: | An empirical formula for calculating the shifted resonant frequencies of Jerusalem-cross frequency selective surfaces (FSSs) with different substrates is derived based on extensive calculations made on widely varying in shifted dual resonant frequencies for substrates with different relative dielectric constants and thickness. The coefficients in the empirical formula were determined by using least-square curve fitting technique to fit 672 sets of shifted resonant frequencies obtained by the HFSS simulator. Numerical results of shifted resonant frequencies obtained from the empirical formula are generally in good agreement with those calculated by the HFSS simulator and measurement. The average error in the shifted resonant frequencies is less than 5 percent. The empirical formula thus provides a simple, inexpensive, and quick method for obtaining optimum geometrical parameters of a dual-band Jerusalem-cross FSS with a substrate consisting of different dielectric constants and thickness for arbitrarily specifying two resonant frequencies. |
| Author(s): | H.-Y. Chen, S.-H. Wen |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 7 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2970 KB |
| Title: | An Efficient Rotationally Symmetric Approach for the Design of Sparse Conformal Arrays in Wide Angle Scanning |
| Abstract: | This paper addresses a novel rotationally symmetric technique with multiple constraints for sparse conformal array synthesis. The purpose is to synthesis a sparse optimal common element positions on the conformal surface varying multiple patterns of wide angle scanning with the behavior of low sidelobe levels (SLL). The conformal surface aperture is partitioned into several rotationally symmetric sections. The element positions and element numbers of only one section need to be optimized, which contribute to the reduction of optimizing variables and computation resources. We formulate the synthesis problem as a constrained optimization problem, which takes the peak sidelobe level (PSLL) as the fitness function, and sets the total number of array elements, the minimum spacing between two adjacent elements to form multiple constraints. The Brain Storm Optimization (BSO) is further exploited into the synthesis problem with multiple constraints. A set of representative numerical examples are presented to assess the advantages and effectiveness of the proposed method. |
| Author(s): | P. Gu, Z. Fan, D. Ding, R. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 3 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2514 KB |
| Title: | An Aperture Coupled MIMO Antenna Decoupling Between Patches Using EBG Structure |
| File Type: | Conference Paper |
| Issue: | Volume: 2-SE-6 Electromagnetic Periodic Structures and EMC/EMI Research Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 917 KB |
| Title: | AN ALTERNATIVE DESCRIPTION OF THE MAGNETIC CURRENT ANNULAR RING (FRILL) SOURCE |
| Abstract: | An alternative method is presented of considering, and of deriving expressions for the fields generated by, an annular ring of magnetic current (magnetic frill source). The magnetic frill appears to offer a means of numerical model excitation that is more realistic than the pulse source and, moreover, provides analytical expressions for fields in some cases. The fields for the magnetic frill source were first derived by Tsai from the electric vector potential produced by the magnetic current. The method described shows the source to resemble a toroidal transformer and the field expressions are derived from the magnetic vector potential produced by electric currents. The expressions derived are, in essence, the same as those of Tsai, but it is considered that the method yields greater physical insight into the source and so facilitates modification to suit particular applications. Tsai's expression which is of most interest for numerical calculations is derived by inspection using the method described. For calculations using point matching however, the benefits of using the frill source seem more apparent than real. [Vol. 5, No. l, pp. 47-62 (1990)] |
| Author(s): | J. W. R. Cox, J. W. R. Cox |
| File Type: | Journal Paper |
| Issue: | Volume: 5 Number: 1 Year: 1990 |
| Download Link: | Click here to download PDF File Size: 714 KB |
| Title: | Air Plasma Key Parameters for Electromagnetic Wave Propagation at and Out of Thermal Equilibrium: Applications to Electromagnetic Compatibility |
| Abstract: | This article addresses the importance of accurate characterization of plasma parameters for electromagnetic compatibility (EMC) purposes. Most of EMC issues involving plasma materials are obviously multi-physics problems (linking chemical, mechanical, thermal and electromagnetic wondering) with deep interactions. One of the main objectives of this paper is to establish the theoretical effect of thermal nonequilibrium of the plasma on electromagnetic wave propagation. This will be characterized throughout plasma key parameters (including complex permittivity). Numerical simulations based upon Finite Integral Technique (FIT) will demonstrate the EMC interest of this methodology for shielding purposes and general air plasma. |
| Author(s): | P. Andre, G. Faure, A. Mahfouf, S. Lallechere |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 12 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2080 KB |
| Title: | Advanced Microfabrication Techniques for the Development of Millimeter-Wave Wafer-Level Waveguide Devices |
| File Type: | Conference Paper |
| Issue: | Volume: 2-3-C Advanced Manufacturing Technologies for Microwave Devices Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 955 KB |
| Title: | Accelerating Out-Of-Core Solvers for Electromagnetic Scattering Simulations with Multiple GPUs |
| File Type: | Conference Paper |
| Issue: | Volume: Direct Matrix Solvers in CEM: PDEs and IEs Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 567 KB |
| Title: | Accelerating Multi GPU Based Discontinuous Galerkin FEM Computations for Electromagnetic Radio Frequency Problems |
| Abstract: | A Graphics Processing Unit (GPU) accelerated simulation of Maxwell’s equations in the time domain is presented. The Discontinuous Galerkin Finite Element Method (DG-FEM) is used for discretization since the elementwise structure fits the parallelization design aspects of the GPU architecture and the NVIDIA Compute Unified Device Architecture (CUDA), a GPU programming model. The parallelization strategy for a multi-GPU setup using CUDA is focused. Several performance improvements are analyzed and investigated with the help of a realistic 3D electromagnetic scattering example. |
| Author(s): | N. Gödel, N. Nunn, T. Warburton, M. Clemens |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 4 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 1302 KB |
| Title: | A-posteriori Estimation of Random Uncertainty for the Reflection Type Q-factor Measurements |
| Abstract: | A frequently used Q factor measurement procedure consists of determining the values of the input reflection coefficient vs. frequency with the use of a network analyzer, and processing the measured values with a data-fitting procedure to evaluate the location and the size of the corresponding Q-circle. That information is then used to compute the value of the loaded and unloaded Q factors and the coupling coefficient of the resonator being tested. This paper describes a novel method of post-processing the measured data, which also provides information on the uncertainty of the obtained results. Numerical examples show that this a-posteriori procedure can not only provide the uncertainty estimates but also improve the accuracy of results, even in the presence of a significant level of random measurement noise. |
| Author(s): | D. Kajfez |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 10 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 2209 KB |
| Title: | A View of Avionics Design of Spacecraft\" Past, Present, and Future |
| File Type: | Conference Paper |
| Issue: | Volume: Posters Session 2 Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 169 KB |
| Title: | A Small-Perturbation Automatic-Di erentiation (SPAD) Method for Evaluating Uncertainty in Computational Electromagnetics |
| File Type: | Conference Paper |
| Issue: | Volume: Mathematical Aspects of CEM Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 361 KB |
| Title: | A Qualitative Deep Learning Method for Inverse Scattering Problems |
| Abstract: | In this paper, we propose a novel deep convolutional neural network (CNN) based qualitative learning method for solving the inverse scattering problem, which is notoriously difficult due to its highly nonlinearity and ill-posedness. The trained deep CNN accurately approximates the nonlinear mapping from the noisy far-field pattern (from measurements) to a disk that fits the location and size of the unknown scatterer. The used training data is derived from the simulated noisy-free far-field patterns of a large number of disks with different randomly generated centers and radii within the domain of interest. The reconstructed fitting disk is also very useful as a good initial guess for other established nonlinear optimization algorithms. Numerical results are presented to illustrate the promising reconstruction accuracy and efficiency of our proposed qualitative deep learning method. |
| Author(s): | H. Yang, J. Liu |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 2 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 2387 KB |
| Title: | A Particle Swarm Optimization to Fit the Debye Model to the Dielectric Properties of Human Tissues |
| File Type: | Conference Paper |
| Issue: | Volume: S52 Biomedical Applications Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 460 KB |
| Title: | A Novel Numerical Approach for the Analysis of 2D MEMS-Based Variable Capacitors with Motion to Arbitrary Directions |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Computational Techniques for System Design Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 99 KB |
| Title: | Performing 3-D FDTD Simulations in less than 3 Seconds on a Personal Computer and its Application to Genetic Algorithm Antenna Optimization |
| Abstract: | FDTD simulations generally require significant computational resources and time. This paper systematically reduces the number of time steps and the grid size to determine the shortest simulation time that returns results with tolerable error for microstrip antenna simulations and their optimization of insertion loss with the genetic algorithm. Although the error would generally be unacceptable for traditional antenna simulations, it is sufficiently small to optimize their design. Simulations in less than 3 seconds on a P4 2.8 GHz processor were shown to be usable, with error approximately equal to manufacturing tolerances. A dual band ‘waffle’ antenna is designed that has better performance than the traditional dual band “F” antenna. |
| Author(s): | L.A. Griffiths, C.M. Furse, L.A. Griffiths, C.M. Furse |
| File Type: | Journal Paper |
| Issue: | Volume: 20 Number: 2 Year: 2005 |
| Download Link: | Click here to download PDF File Size: 313 KB |
| Title: | To-Average or Not-to-Average in FDTD Modeling of Dielectric Interfaces |
| Abstract: | Accurate Finite Difference Time Domain (FDTD) modeling of localized electromagnetic sources such as cellular telephones near the human body requires very precise modeling of the location of these devices. This paper discusses the effective location of near field sources when dielectric interface cells are made up of either averaged or unaveraged dielectric properties. It is shown that either method can accurately define the proximity between source and dielectric, but that the effective location differs by half an FDTD cell in the two methods. |
| Author(s): | Cynthia Furse, Craig Waterman, Lance Griffiths, Cynthia Furse, Craig Waterman, Lance Griffiths |
| File Type: | Journal Paper |
| Issue: | Volume: 21 Number: 2 Year: 2006 |
| Download Link: | Click here to download PDF File Size: 306 KB |
| Title: | A Solution of One-Dimensional Stationary Schrodinger Equation by the Fourier Transform |
| Abstract: | In this paper, a new numerical method for solving of one-dimensional stationary Schrödinger equation has been presented. The method is based on the Fourier transform of a wave equation. It is shown that, as a result we obtain an integral equation where integral is replaced by sum. A main problem is transformed in the eigenvalue/eigenvector problem which corresponds to discrete energy levels as well as the Fourier transform of wave functions. Wave function is obtained by usage of the inverse Fourier transform. Discrete energy levels are split and form the forbidden and permitted zones for the one-dimensional finite crystal. The method is tested in many examples, and it is characterized by high accuracy and stability of search of the discrete energy levels. |
| Author(s): | V. M. Fitio, I. Y. Yaremchuk, V. V. Romakh, Y. V. Bobitski |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 5 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 625 KB |
| Title: | Metamaterials for High Power Reflectarray Design |
| File Type: | Conference Paper |
| Issue: | Volume: S10 Metamaterials and FSS I Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 1111 KB |
| Title: | CURRENT-BASED HYBRID MOMENT METHOD ANALYSIS OF ELECTROMAGNETIC RADIATION AND SCATTERING PROBLEMS |
| Abstract: | A current-based hybrid method combining the method of moments (MM) with asymptotic current expansions for the higher frequency range is presented for the analysis of arbitrarily shaped, three-dimensional, perfectly conducting electromagnetic radiation and scattering problems. Some examples demonstrate the drastic saving in memory requirement and CPU-time when applying the hybrid method as compared to the conventional MM. Even though the proposed method is a frequency domain formulation, some time domain results based on a Fourier transform are presented as they show an accurate description of diffracted and creeping waves. [Vol. 10, No. 3 (1995), Special Issue on Advances in the Application of Method of Moments to Electromagnetic Radiation and Scattering Problems, pp 38-46 |
| Author(s): | Ulrich Jakobus, Friedrich M. Landstorfer, Ulrich Jakobus, Friedrich M. Landstorfer |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 3 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 739 KB |
| Title: | PARAMETRIC MAPPING OF VECTOR BASIS FUNCTIONS FOR SURFACE INTEGRAL EQUATION FORMULATIONS |
| Abstract: | A parametric mapping of vector basis functions is presented for curved-patch discretizations of surface integral equations. The mapping of the vector basis function maintains the normal continuity of the surface current density at cell boundaries, and is therefore suitable for use with the electric-field integral equation. Expressions for the matrix elements associated with the electric and magnetic field integral equations are developed. [Vol. 10, No. 3 (1995), Special Issue on Advances in the Application of Method of Moments to Electromagnetic Radiation and Scattering Problems, pp 107-115] |
| Author(s): | Andrew F. Peterson, Keith R. Aberegg, Andrew F. Peterson, Keith R. Aberegg |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 3 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 632 KB |
| Title: | APPLICATION OF THE UMOM FOR THE COMPUTATION OF THE SCATTERING BY DIELECTRICS COATED WITH WEAKLY NONLINEAR LAYERS |
| Abstract: | The paper describes an iterative approach to the computation of the electromagnetic scattering by isotropic, dielectric objects partially made of weakly nonlinear materials The approach is started by using a perturbative moment-method solution based on the Sherman-MorrisonWoodbury formula. The nonlinearity is assumed to be of the Kerr type, i e, the dielectric permittivity depends on the square amplitude of the electric field The bistatic scattering width and the field distribution are computed for some test cases, in particular, for infinite cylinders coated and filled with nonlinear materials The convergence of the medium is numerically evaluated and the results are compared with those obtained by the iterative distorted-wave Born approximation. [Vol. 10, No. 3 (1995), Special Issue on Advances in the Application of Method of Moments to Electromagnetic Radiation and Scattering Problems, pp 139-145] |
| Author(s): | Salvatore Caorsi, Andrea Massa, Matteo Pastorino, Salvatore Caorsi, Andrea Massa, Matteo Pastorino |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 3 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 561 KB |
| Title: | ON THE COMBINATION OF MMP WITH MOM |
| Abstract: | The Multiple Multipole Program (MMP) [1] is based on the Generalized Multipole Technique (GMT) [2]. This method lies between a purely analytic solution and the well-known Method of Moments (MoM) [3]. The goal of this paper is to demonstrate how a combination of MMP with MoM can be achieved for obtaining more powerful codes. The combination presented here is based on an implementation of rooftop functions as a new type of basis function in 3D MMP. Since users of this code are often interested in the close near-field, a special implementation of rooftop functions is presented and tested. (Vol. 9, No. 3 (1994), Special Issue on Generalized Multipole Technique (GMT), pp 18-27] |
| Author(s): | Ch. Hafner, J. Waldvogel, J. Mosig, J. Zheng, Y. Brand, Ch. Hafner, J. Waldvogel, J. Mosig, J. Zheng, Y. Brand |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 3 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 6282 KB |
| Title: | ANALYSIS AND COMPUTATION OF LEAKY-WAVE HYPERTHERMIA APPLICATOR |
| Abstract: | The use of electromagnetic waves to induce hyperthermia in cancer therapy has been the subject of intensive research but obtaining good resolution at depth in the abdomen and pelvic regions remains a fundamental problem. This paper investigates the prospects for generating leaky-waves in tissue to improve field penetration and focussing at depth. An approximate analysis based on a planar structure illustrates the feasibility of obtaining good resolution at depth but leaky-wave action in a strict sense is not possible. Measurements on an applicator conformal with the phantom tissue simulated by a saline solution, demonstrate good resolution and penetration but hotspot regions are detected around the launcher region. A three dimensional finite difference time domain (FDTD) computation is performed in Cartesian, circular cylindrical and elliptic cylindrical coordinates to model all the effects for various geometries of the phantom region and different launching symmetries. The results illustrate the need for symmetric launching of the strip, computational convergence and mode diagnostic data, the shape of the focal region and the useful property of being able to shift the focal region by changing frequency. It is concluded that this new quasi-leaky-wave applicator concept is potentially capable of giving improved focal resolution at depth with some positional control and only one generator is required. Optimising the launching of the quasi- leaky waves on the applicator and preventing hotspot regions from creating unwanted tissue heating are remaining practical problems to address. [Vol. 7, No. 2, pp. 72-84 (1992), Special Issue on Bioelectromagnetic Computations] |
| Author(s): | J. R. James, G. Andrasic., J. R. James, G. Andrasic. |
| File Type: | Journal Paper |
| Issue: | Volume: 7 Number: 2 Year: 1992 |
| Download Link: | Click here to download PDF File Size: 2500 KB |
| Title: | TWO-DIMENSIONAL TEMPERATURE RETRIEVAL IN BIOLOGICAL STRUCTURES BY MULTIFREQUENCY MICROWAVE RADIOMETRY: A SOBOLEV-SPACE SOLUTION |
| Abstract: | The problem of retrieving a two-dimensional temperature distribution from radiometric data measured at various frequencies and for different positions of the sensing antenna around the body has been considered. The retrieval has been modelled as an inverse problem whose solution is investigated in a suitably defined functional space which takes regularity properties of temperature functions into account. The retrieval of hot spots in a cylinder at uniform temperature has been numerically analyzed, the examples being relevant in the hyperthermia treatment of malignancies. [Vol. 7, No. 2, pp. 110-120 (1992), Special Issue on Bioelectromagnetic Computations] |
| Author(s): | Fernando Bardati, Valerie J. Brown, Piero Tognolatti, Fernando Bardati, Valerie J. Brown, Piero Tognolatti |
| File Type: | Journal Paper |
| Issue: | Volume: 7 Number: 2 Year: 1992 |
| Download Link: | Click here to download PDF File Size: 740 KB |
| Title: | A HYBRID FINITE ELEMENT FOR CONDUCTORS WITH THIN DENSE COATINGS |
| Abstract: | A hybrid method of using finite elements and boundary integral methods to compute scattering from two dimensional coated conductors is presented. Finite elements are used in and around an electrically dense coating where high sampling rates are required. Since the matrix equations they generate are sparse, they can be quickly solved. The finite element sampling rate is reduced with distance from the scatterer to a very low rate where the boundary integral method provides the exact near field radiation condition. The boundary integral generates a dense matrix which is small due to the reduced sampling. This technique is compared for accuracy and efficiency with series solutions and with method of moments. [Vol. 4, No. 2, pp. 59-72 (1989)] |
| Author(s): | Willlam E. Boyse, Andrew A. Seidl, Willlam E. Boyse, Andrew A. Seidl |
| File Type: | Journal Paper |
| Issue: | Volume: 4 Number: 2 Year: 1989 |
| Download Link: | Click here to download PDF File Size: 982 KB |
| Title: | HYBRID MOM/SBR METHOD TO COMPUTE SCATTERING FROM A SLOT ARRAY ANTENNA IN A COMPLEX GEOMETRY |
| Abstract: | A method of moments (MoM) code has been developed to compute the scattering from a pla-nar or cylindrically conformal slot array antenna. By hybridizing the MoM with the shooting and bouncing ray (SBR) method, the scattering from a large, complex target with a slot array antenna can be computed. The scattering problem can be decomposed using the field equivalence prin-ciple such that the MoM is employed to model the slot array while the SBR method is used to compute the scattering from the large, complex target. Sample results show the utility of the method and the need to include slot array scat-tering when computing the RCS of a complex target. |
| Author(s): | Andrew D. Greenwood, Jian-Ming Jin, Andrew D. Greenwood, Jian-Ming Jin |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 1 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 514 KB |
| Title: | ON THE BOUNDED PART OF THE KERNEL IN THE CYLINDRICAL ANTENNA INTEGRAL EQUATION |
| Abstract: | The kernel in the cylindrical antenna integral equation was partitioned by Schelkunoff into a com-plete elliptic integral and a bounded integral. This paper gives an exact expression for the bounded part. |
| Author(s): | M. P. Ramachandran, M. P. Ramachandran |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 1 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 343 KB |
| Title: | HIGHLY PARALLEL IMPLEMENTATION OF THE 3D INTEGRAL EQUATION ASYMPTOTIC PHASE METHOD FOR ELECTROMAGNETIC SCATTERING |
| Abstract: | In this paper, we discuss the implementation of the 3D Integral Equation-Asymptotic Phase (IE-AP) method using the parallel architecture IBM RS/6000 SP. The IE-AP method is a hybrid numerical/asymptotic approach for electromagnetic scattering that attempts to reduce the number of unknowns required to accurately model electrically large structures. The IE-AP method will be described, and results will be reported for the parallel matrix fill implementation, and the relative performance of the PESSL and PETSc toolkits for parallel matrix solution. |
| Author(s): | Xianneng Shen, Aaron W. Davis, Keith R. Aberegg, Andrew F. Peterson, Xianneng Shen, Aaron W. Davis, Keith R. Aberegg, Andrew F. Peterson |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 2 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 651 KB |
| Title: | FAST FREQUENCY RESPONSE CALCULATIONS OF CAVITY-BACKED APERTURE ANTENNAS USING HYBRID FEM/MOM TECHNIQUE IN CONJUNCTION WITH MODEL BASED PARAMETER ESTIMATION |
| Abstract: | Model Based Parameter Estimation (MBPE) is presented in conjunction with the hybrid Finite Element Method (FEM)/Method of Moments (MoM) technique for fast computation of the input characteristics of cavity-backed aperture antennas over a frequency range. The hybrid FEM/MoM technique is used to form an integro-partial-differential equation to compute the electric field distribution of a cavity-backed aperture antenna. In MBPE, the electric field is expanded as a rational function of two polynomials. The coefficients of the rational function are obtained using the frequency derivatives of the integro-partial-differential equation formed by the hybrid FEM/MoM technique. Using the rational function approximation, the electric field is calculated and the input characteristics of the antenna are obtained over the frequency range. Numerical results for an open coaxial line and a cavity-backed microstrip patch antenna are presented. Good agreement between MBPE and the solutions over individual frequencies is observed. CPU timings for all numerical calculations are presented. |
| Author(s): | C. J. Reddy, , M. D. Deshpande, B. R. Cockrell, F. B. Beck, C. J. Reddy, , M. D. Deshpande, B. R. Cockrell, F. B. Beck |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 3 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 575 KB |
| Title: | A Hybrid Mom/FEM Technique for Scatter from a Complexe BOR with Appendages |
| Abstract: | A hybrid technique is developed to allow the scattering from small appendages to be approximately combined with the scatter from a large body of revolution (BOR). The hybrid technique thus enables the rotational symmetry of the large BOR to be exploited to solve the scattering problem with much less computational complexitity than a fully three-dimensional (3-D) solution. The technique combines the finite element method (FEM) for BOR scattering with the method of moments (MoM) for small appendages. The hybrid forumlation is discussed in detail, including an approximate Green's function with permits the decoupling of the solutions from the FEM and the MoM. Numerical examples are given to show the applicability and accuracy of the hybrid technique. |
| Author(s): | Andrew D. Greenwood, Jian-Ming Jin, Andrew D. Greenwood, Jian-Ming Jin |
| File Type: | Journal Paper |
| Issue: | Volume: 15 Number: 1 Year: 2000 |
| Download Link: | Click here to download PDF File Size: 2981 KB |
| Title: | Optimum Population Size and Mutation Rate for a Simple Real Genetic Algorithm that Optimizes Array Factors |
| Abstract: | The population size and mutation rate of a genetic algorithm have great influence upon the speed of convergence. Most genetic algorithm enthusiants use a large population size and low mutation rate due to the recommendations of several early studies. These studies were somewhat limited. This paper presents results that show a small population size and high mutation rate are actually better for many problems. |
| Author(s): | Randy L. Haupt, Sue Ellen Haupt, Randy L. Haupt, Sue Ellen Haupt |
| File Type: | Journal Paper |
| Issue: | Volume: 15 Number: 2 Year: 2000 |
| Download Link: | Click here to download PDF File Size: 9141 KB |
| Title: | On the Implementaion of the Equivalence Theorem in the Hybrid FDTD-MoMTD Technique |
| Abstract: | The hybrid FDTD-MoMTD technique is a powerful tool for analysing the transient excitation of inhomogeneous permeable bodies by arbitrary thin-wire antennas. The technique is based upon the calculation of the equivalent electric and magnetic currents on a Huygen's surface that encloses the antenna. The paper studies, by means of several numerical experiments, the effects on the accuracy of the results of the size of the Huygen's box, the size of the spatial increment in the FDTD algorithm and the distance from the Huygen's surface to the observation point. |
| Author(s): | M. A. Hernandez-Lopez, A. Ruibo Bretones, M. Quintillan, R. Gomez Martin, M. A. Hernandez-Lopez, A. Ruibo Bretones, M. Quintillan, R. Gomez Martin |
| File Type: | Journal Paper |
| Issue: | Volume: 16 Number: 1 Year: 2001 |
| Download Link: | Click here to download PDF File Size: 409 KB |
| Title: | A MICROWAVE IMAGING APPROACH BASED ON AMPLITUDE-ONLY DATA FOR THE RECONSTRUCTIN OF THE ELECTROMAGNETIC FIELD INDUCED IN BIOLOGICAL PHANTOMS |
| Abstract: | In this paper, a microwave imaging technique for the reconstructin of the electromagnetic field distribution inside exposed biological bodies from amplitude-only data is presented. The scattering problem, formulated in terms of integral equations, is recast into an optimization problem after defining a suitable cost function which is proportional to the difference between reconstructed and measured amplitudes of the scattered and of the incident electric fields in the near-field region. The field solution is obtained by minimizing the cost function by means of an hybrid simulated annealing-conjugate gradient based procedure, which, in principle, ensures the convergence to the global minimum, preventing the solution from being trapped in local minima. Moreover, the proposed approach prevents the problems due to inaccuracies in near-field phase measurements. The effectiveness of the microwave imaging approach is assessed by means of some numerical expamples (with synthetic input data) concerning a realistic cross-section of a biological phantom exposed to a TM electromagnetic illumination. The presence of noise on synthetic data is also considered and the dependence of the reconstruction accuracy on the signal-to-noise ratio investigated. Finally, in order to give some indications to further improve the prediction capability of the proposed approach, some preliminary guidelines are pointed out. |
| Author(s): | Salvatore Caorsi, Emanuela Bermani, Andrea Massa, Salvatore Caorsi, Emanuela Bermani, Andrea Massa |
| File Type: | Journal Paper |
| Issue: | Volume: 16 Number: 2 Year: 2001 |
| Download Link: | Click here to download PDF File Size: 1321 KB |
| Title: | Methods for the Evaluation of Regular, Weakly Singular and Strongly SingularSurface Reaction Integrals Arising in Method of Moments |
| Abstract: | The accurate and fast evaluation of surface reaction integrals for Method of Moments computations is presented. Starting at the classification of the integrals into regular and weakly, strongly and nearly singular integrals, appropriate methods are presented that handle each. A Gauss-Legendre quadrature rule evaluates regular integrals. For singular integrals, the singularity is lifted or weakened by an extraction of the singularity, a transform to polar coordinates or a domain transform. The resulting regular integral is in turn solved by a quadrature rule. The different methods are finally applied to an example, and the resulting accuracy tested against the analytical result. The presented methods are general enough to be used as integration methods for integrands with various degrees of singularity and is not limited to Method of Moments. |
| Author(s): | Alexander Herschlein, Juergen v. Hagen, Werner Wiesbeck, Alexander Herschlein, Juergen v. Hagen, Werner Wiesbeck |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 1 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 340 KB |
| Title: | Accuracy of currents produced by the locally-corrected Nystrom method and the method of moments when used with higher-order representations |
| Abstract: | The locally-corrected Nyström method is described, and the accuracy of the currents produced by it and the method of moments are compared. Results suggest that when the underlying representation has the same order, the methods are comparable in accuracy. Additional results are presented to illustrate the Nyström approach, and advantages and disadvantages of the method are reported. |
| Author(s): | Andrew F. peterson, Andrew F. peterson |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 1 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 184 KB |
| Title: | High-Order Nystrom Method for Computing Waveguide Modes |
| Abstract: | We report a novel method for accurately computing the modes of an arbitrarily-shaped hollow waveguide. Our method uses a point-based (Nystrom) discretization of an integral operator over the waveguide aperture to compute the modes. |
| Author(s): | J. J. Ottusch, S. M. Wandzura, J. J. Ottusch, S. M. Wandzura |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 1 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 2246 KB |
| Title: | Electric Dyadic Green's Functions for Modeling Resonance and Coupling Effects in Waveguide-Based Aperture-Coupled Patch Arrays |
| Abstract: | An efficient technique for the rapid development of electric Green's dyadics of a transversely layered, terminated rectangular waveguide is presented with application to waveguide-based aperture-coupled patch arrays. This technique uses a partial eigenfunction expansion resulting in a Sturm-Liouville problem for one-dimensional characteristic Green's functions in the waveguiding direction. In this representation, the one-dimensional characteristic Green's functions provide physical insight into resonance and surface wave effects occurring in overmoded layered waveguide transitions. Particularly, this is related to the correlation between transverse resonances in the waveguide cross-section and surface waves associated with a grounded dielectric slab waveguide. This is demonstrated for the examples of aperture-coupled patch arrays in the N-port waveguide transition, although the analysis is applicable to other waveguide-based antenna structures, which allow for the propagation of surface waves. |
| Author(s): | Alexander B. Yakovlev, Sean Ortiz, Mete Ozkar, Amir Mortazawi, Michael B. Steer, Alexander B. Yakovlev, Sean Ortiz, Mete Ozkar, Amir Mortazawi, Michael B. Steer |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 2 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 234 KB |
| Title: | A Comparative Study of NN and SVM-Based Electromagnetic Inverse Scattering Approaches to On-Line Detection of Buried Objects |
| Abstract: | Microwave-based sensing techniques constitute an important tool for the detection of buried targets. In this framework, a key issue is represented by real-time scatterer localization. As far as such a topic is concerned, this paper presents a comparative evaluation of the performances provided by a conventional NN-based inverse scattering technique and by a new SVM-based electromagnetic approach. In order to estimate the effectiveness values of the two methods, realistic configurations and noisy enviornments are considered and current capabilities, as well as potential limitations, are pointed out. Finally, possible future research work is outlined. |
| Author(s): | Salvatore Caorsi, Davide Anguita, Emanuela Bermani, Andrea Boni, Massimo Donelli, Salvatore Caorsi, Davide Anguita, Emanuela Bermani, Andrea Boni, Massimo Donelli |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 2 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 319 KB |
| Title: | Accelerating Computations with a MoM-Based Computer Program |
| Abstract: | Electromagnetic research often requires studies within wider frequency ranges. For achieving a fine resolution in the frequency domain, the required computation time is usually high. Here the MoM-based field computation program FEKO working in frequency domain is used for this purpose. In order to reduce the computational costs by minimizing the number of sampling points used, the interpolation algorithm MPBE (Model Based Parameter Estimation) is applied to achieve a mathematically based approximation of the problem. This paper presents the acceleration of computations with FEKO using the interpolation algorithm MBPE. A short introduction to FEKO is given at the beginning. Subsequently the implementation of MBPE as well as three possible adaptive strategies for further shortening the computation time is presented. Finally examples are given that show the advantages of this implemented method. |
| Author(s): | M. Schick, F. M. Landstorfer, M. Schick, F. M. Landstorfer |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 3 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 878 KB |
| Title: | Computation of SAR in Cell Culture Flasks Exposed to 900 MHz GSM Type Signals in a Modified TEM Cell |
| Abstract: | In order to provide rigorous dosimetry for in vitro studies, Telstra Research Laboratories has developed a modified transverse electromagnetic cell exposure system. The system acts as a chamber for experiments in which a human cell culture exists as a very thin monolayer adhered to the bottom of a plastic culture flask under a layer of several millimetres of RPMI nutrient medium while incubated in a controlled atmosphere. A key to the rigour of any experiment seeking to investigate possible effects of electromagnetic energy on living systems is to ensure that the exposures used are accurately known, and to achieve this, numerical methods for the challenging task of characterising the SAR profile in the medium have been developed. This paper describes salient aspects of the development and analysis of the system. |
| Author(s): | R. L. McIntosh, R. J. McKenzie, S. Iskra, A. Carratelli, P. Standaert, R. L. McIntosh, R. J. McKenzie, S. Iskra, A. Carratelli, P. Standaert |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 3 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 238 KB |
| Title: | High Accuracy Calculation of the Magnetic Vector Potential on Surfaces |
| Abstract: | |
| Author(s): | Malcolm M. Bibby, Andrew F. Peterson, Malcolm M. Bibby, Andrew F. Peterson |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 1 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 395 KB |
| Title: | Numerical Study of Coupling between Coagulators and Electrodes of Cardiac Pacemakers under Consideration of the Human Body |
| Abstract: | The paper presents a numerical, worst-case study of the coupling between coagulators and cardiac pacemakers under consideration of the human body. For this purpose two special body models have been implemented. With these models whose electrical properties correspond to a weighted average of those of different tissues of the human body the influence of the latter can be taken into account in the computations. Different parameters such as position of the pacemaker and its electrode, coagulation frequency, and coagulation point on the surface of the human body are considered. Based on results of previous investigations simplified approaches to account for the dielectric coating of the coagulator electrode and housing of the pacemaker can be used. The investigation shows, that for the scenario described above, strong peaks occur in the resulting graphs arising form resonance effects on the coagulator cable. |
| Author(s): | Markus Schick, Friedrich M. Landstorfer, Markus Schick, Friedrich M. Landstorfer |
| File Type: | Journal Paper |
| Issue: | Volume: 19 Number: 1 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 6529 KB |
| Title: | FDTD Analysis of a Probe-Fed Dielectric Resonator Antenna in Rectangular Waveguide |
| Abstract: | Dielectric resonator antennas (DRA) are characterized for operation in a guided-wave environment with the ultimate goal of their use in modeling of waveguide-based DRA amplifier arrays for spatial power combining. Performance of a single probe-fed DRA element in rectangular waveguide is analyzed by varying design parameters of the DRA and the feeding probe to optimize the structure for the scattering characteristics (port matching and coupling). The effect of hard walls on the DRA behavior is also studied. The numerical analysis of waveguide-based DRA elements is based on the Finite-Difference Time-Domain (FDTD) method and a coaxial probe is modeled by a thin wire approximation implemented in the FDTD algorithm. The numerical results are compared with those generated by using commercial software and exhibit a very good agreement. |
| Author(s): | Yizhe Zhang, Ahmed A. Kishk, Alexander B. Yakovlev, Allen W. Glisson, Yizhe Zhang, Ahmed A. Kishk, Alexander B. Yakovlev, Allen W. Glisson |
| File Type: | Journal Paper |
| Issue: | Volume: 21 Number: 1 Year: 2006 |
| Download Link: | Click here to download PDF File Size: 347 KB |
| Title: | Comparison of WIPL-D to Other EM Computation Methods |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling Using WIPL-D Code(II) Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 214 KB |
| Title: | Computer-Aided Design of Compact Dual Frequency Arrow Shaped Microstrip Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Computational Techniques for Antenna Design Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 187 KB |
| Title: | Improving the Numerical Efficiency of Generalized Multipole Technique by Non-redundant Multipole Choices |
| File Type: | Conference Paper |
| Issue: | Volume: Computational Techniques Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 435 KB |
| Title: | Analyzing the Stability of the New FDTD Technique for Non-Dispersive Bi-Isotropic Media Using the von Neumann Method. |
| File Type: | Conference Paper |
| Issue: | Volume: Bianisotropic and Metamaterial Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 205 KB |
| Title: | New Ray-Tracing Techniques and Propagation Modeling for Challenging Communication Environments |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 549 KB |
| Title: | Application of an iterative method for the solution of electromagnetic scattering from wire antennas |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 167 KB |
| Title: | Design and Optimisation of an Antenna Array for WIMAX Base Stations |
| File Type: | Conference Paper |
| Issue: | Volume: Beamforming and Smart Antennas Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 816 KB |
| Title: | Hard and Soft Surfaces Realized by Frequency Selective Surfaces on a Grounded Dielectric Slab |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Analysis of Wave Phenomena Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 207 KB |
| Title: | European effort towards a unified framework for the analysis of antenna structures |
| File Type: | Conference Paper |
| Issue: | Volume: Special Session: Recent Electromagnetics & Antennas Activities in the European Network "ACE" Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 153 KB |
| Title: | Propagation Prediction Software for Wireless Communication System Optimization |
| File Type: | Conference Paper |
| Issue: | Volume: Propagation Channel Characterization Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 379 KB |
| Title: | Efficient Calculation of Field Distribution with High-Resolution Using Ray-Tracing Method |
| File Type: | Conference Paper |
| Issue: | Volume: Fast and Efficient CEM Methods Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 268 KB |
| Title: | Study of Electromagnetic Scattering From Material Object Doped Randomely WithThin Metallic Wires Using Finite Element Method |
| File Type: | Conference Paper |
| Issue: | Volume: Hybrid CEM Techniques Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 121 KB |
| Title: | Analysis of a Linear Slot Array Comprised of Tilted Edge Slots Cut in the Narrow Wall of a Rectangular Waveguide |
| File Type: | Conference Paper |
| Issue: | Volume: Special Session: Communication Antenna Analysis and Design Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 160 KB |
| Title: | Narrow Beam Adaptive Array for Advanced Wireless Applications |
| File Type: | Conference Paper |
| Issue: | Volume: Special Session: Communication Antenna Analysis and Design Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 349 KB |
| Title: | The Influence of Data Density on the Consistency of Performance of the Feature Selective Validation (FSV) Technique |
| Abstract: | The human visual system has an immense capacity for compensating for poor or incomplete data. Psycho-visual coding schemes make use of the brain’s ability to extrapolate and interpolate independently of conscious awareness to reduce data (bit) rates but maintain the same level of ‘information’ within a video signal. However, when attempting to produce a simple method for comparing data-sets, primarily for validation of computational electromagnetics, could give rise to a problem. Namely that someone undertaking the visual inspection of (e.g.) modeled data against experimental data will see the same picture whether sampled at N, 100N or 0.01N data points whereas the software undertaking the comparison would process three very different data sets. The Feature Selective Validation (FSV) method was developed to attempt to mimic the group response of a number of experts undertaking the visual comparison. Hence, the quality of performance of the FSV method should not be severely affected by the number of data points if this assertion is to hold, despite the obvious potential for variation. This paper investigates the FSV performance as a function of data density and shows that the accuracy of its performance remains largely unimpeded by variations in the precision of the data supplied. |
| Author(s): | Alistair Duffy, Antonio Orlandi, Alistair Duffy, Antonio Orlandi |
| File Type: | Journal Paper |
| Issue: | Volume: 21 Number: 2 Year: 2006 |
| Download Link: | Click here to download PDF File Size: 294 KB |
| Title: | Genetic Algorithm Optimization of a Traveling Wave Array of Longitudinal Slots in a Rectangular Waveguide |
| Abstract: | Abstract — Genetic Algorithm is used to optimize the performance characteristics of a traveling wave array consisting of longitudinal slots cut in the broad wall of a rectangular waveguide. An analysis method employing a loaded transmission line to model the slot arrays is employed. External mutual coupling is considered. The self admittance of the radiating slots is computed using the method-of-moments technique applied to the pertinent integral equations. Numerical results indicate typical performance improvements possible using the genetic algorithm optimization. |
| Author(s): | Anders Jensen, Sembiam R. Rengarajan, Anders Jensen, Sembiam R. Rengarajan |
| File Type: | Journal Paper |
| Issue: | Volume: 21 Number: 3 Year: 2006 |
| Download Link: | Click here to download PDF File Size: 496 KB |
| Title: | Cascading Optical Negative Index Metamaterials |
| Abstract: | We use a spatial harmonic analysis (SHA) method to homogenize optical metamaterials with a negative refractive index; the method provides a more general approach than other methods for estimating the effective index of materials arranged of cascaded elementary layers. The approach is validated for a single layer and a triple layer two dimensional metal grating. |
| Author(s): | Alexander V. Kildishev, Uday K. Chettiar, Alexander V. Kildishev, Uday K. Chettiar |
| File Type: | Journal Paper |
| Issue: | Volume: 22 Number: 1 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 395 KB |
| Title: | Characterizing Infrared Frequency Selective Surfaces on Dispersive Media |
| Abstract: | With the emergence of frequency selective surfaces (FSS) and other passive planar antenna devices at infrared frequencies, the increasing need for accurate characterization using numerical modeling prior to device fabrication has exposed limitations in the traditional modeling procedures used for lower frequency FSS designs. To improve full-wave FSS models at IR, a procedure to measure and integrate dispersive material properties in modeling is described. Measured and modeled results are provided as verification demonstrating the need to account for material dispersion in infrared FSS design. |
| Author(s): | James Ginn, Brian Lail, David Shelton, Jeffrey Tharp, William Folks and Glenn Boreman, James Ginn, Brian Lail, David Shelton, Jeffrey Tharp, William Folks and Glenn Boreman |
| File Type: | Journal Paper |
| Issue: | Volume: 22 Number: 1 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 509 KB |
| Title: | Investigation of Wire Grid Modeling in NEC Applied to Determine Resonant Cavity Quality Factors |
| Abstract: | Numerical computer simulations using the NEC Method of Moments (MoM) code were performed on wire grid models of resonant cavities in order to study how well conductive structures and their surface impedances can be modeled by wire meshes. The resonant cavity quality factor, or Q, was examined due to its high sensitivity to surface impedance. Several half-wave coaxial cavities were simulated using various mesh element sizes. The cavities’ outer conductor radius was varied to obtain different geometries. The quality factor Q was determined from the simulated input impedance spectra. The wire grid model results were compared to well known theoretical and experiment results. Qualitative agreement between simulation, theoretical, and experimental results was achieved for fixed mesh parameters, giving confidence in comparative simulation using the same wire grid meshing parameters. Quantitative agreement of simulation results was achieved through repeated simulation with varying mesh element lengths and extrapolating the simulation results to a conceptual mesh element length of zero. This shows that simulations to determine quantities sensitive to surface impedances can be successfully performed with codes such as NEC. |
| Author(s): | Franz A. Pertl, Andrew D. Lowery, James E. Smith, Franz A. Pertl, Andrew D. Lowery, James E. Smith |
| File Type: | Journal Paper |
| Issue: | Volume: 22 Number: 3 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 297 KB |
| Title: | Characterization of Meta-Materials Using Computational Electromagnetic Methods |
| File Type: | Conference Paper |
| Issue: | Volume: Metamaterials Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 241 KB |
| Title: | Numerical Modeling Interaction of RF Field in MRI with a Pregnant Female Model |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Imaging Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 138 KB |
| Title: | Lightning Electromagnetic Fields Computation using Time Domain Finite Element Method |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Time Domain Techniques Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 68 KB |
| Title: | A Multiresolution Model of Transient Microwave Signals in Dispersive Chiral Media |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Time Domain Techniques Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 214 KB |
| Title: | Low-cost Nonplanar Microstrip-line Ferrite Phase Shifter Utilizing Circular Polarization |
| File Type: | Conference Paper |
| Issue: | Volume: Phased Array and Active Antennas Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 217 KB |
| Title: | Slot Antenna for Ultra Wideband System |
| File Type: | Conference Paper |
| Issue: | Volume: Wideband Antennas Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 257 KB |
| Title: | Comparative Study of Wideband Properties of Planar Solid and Strip Fractal Bow-Tie Dipoles |
| File Type: | Conference Paper |
| Issue: | Volume: Wideband Antennas Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 775 KB |
| Title: | High Performance Low Cost Ferroelectric Phase Shifters Designed for Simple Biasing |
| File Type: | Conference Paper |
| Issue: | Volume: Special Session: Electromagnetic Modeling by WIPL-D Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 211 KB |
| Title: | Numerical Simulation of the Generation of Synchrotron Radiation in a Vacuum Chamber with FEKO |
| File Type: | Conference Paper |
| Issue: | Volume: FEKO Modeling and Analysis - 2 Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 257 KB |
| Title: | Self-Adjoint Sensitivity Analysis of High-Frequency Structures with FEKO |
| File Type: | Conference Paper |
| Issue: | Volume: FEKO Modeling and Analysis - 2 Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 195 KB |
| Title: | Fast Hybrid CAD Technique for the Optimization of Advanced Waveguide Components and Aperture Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: Hybrid Techniques Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 1500 KB |
| Title: | Self-Adjoint Sensitivity Analysis of High-Frequency Structures with FEKO |
| File Type: | Conference Paper |
| Issue: | Volume: Poster Session- Students Paper Competition Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 195 KB |
| Title: | Modeling Localized Surface Plasmons in Light Tunneling and New Optical Sensing Approach |
| File Type: | Conference Paper |
| Issue: | Volume: Computational Electromagnetics for Photonics Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 208 KB |
| Title: | Low-frequency analysis of electromagnetic interference from SMPS |
| File Type: | Conference Paper |
| Issue: | Volume: Innovation in the Macromodeling of High Speed Interconnects Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 206 KB |
| Title: | Optimization of a High-Speed Interconnect Link Under Signal Integrity Constraints |
| File Type: | Conference Paper |
| Issue: | Volume: Innovation in the Macromodeling of High Speed Interconnects Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 500 KB |
| Title: | Parallelized Integral Equation Methods for Signal Integrity |
| File Type: | Conference Paper |
| Issue: | Volume: Macromodeling for EMC and SI Complex Systems Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 101 KB |
| Title: | Analysis of Photonic Band Gap using Multilayer Contribution of Wave Concept Iterative Process MLC-WCIP |
| Abstract: | Microstrip elements are modeled in multilayered contribution. An iterative method based on the concept of waves is developed in a form useful for efficient computation for interacting microstrip elements, which may be located at any substrate layer and separated by a large distance. The multilayer contribution of iterative method is developed in the spatial domain. Examples for regularly shaped geometries in multilayered media are presented. These involve the optimization of a microstrip ring with a narrow gap which induces multiple reflections with a fixed phase correlation necessary to make the photonic band gap. The analysis takes into account eventual coupling parasites. Experimental measurements are performed to validate the computation. The approach involves the mixed magnetic and electric field equation technique and the wave concept iterative process which involves S-parameters extraction technique. In this sense, a program in FORTRAN has been elaborated to determine different parameters Sij characterizing the studied structure. A good agreement between numerical and reported results is important to validate the theory of the multilayer contribution of iterative method MLC-WCIP. |
| Author(s): | E. A. Hajlaoui, H. Trabelsi, A. Gharsallah, H. Baudrand |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 3 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 281 KB |
| Title: | A Mode Selecting Eigensolver for 2D FIT Models of Waveguides |
| Abstract: | For the computation of eigenmodes in multimodal waveguide structures, the Jacobi- Davidson eigenvalue solver is extended by a vector-based weighting function. It allows to generate only modes with a desired field distribution. The performance of this solver is studied by means of an eigenmode computation in a photonic crystal fiber which is discretized by the finite integration technique. The new algorithm is able to separate the modes in the fiber core from a number of non-physical modes which originate from a transversal PML-type boundary condition. |
| Author(s): | B. Bandlow, R. Schuhmann |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 6 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 461 KB |
| Title: | Application of the Normalized Surface Magnetic Source Model to a Blind Unexploded Ordnance Discrimination Test |
| Abstract: | The Normalized Surface Magnetic Source (NSMS) model is applied to unexploded ordnance (UXO) discrimination data collected at Camp Sibert, AL, with the EM63 electromagnetic induction sensor. The NSMS is a fast and accurate numerical forward model that represents an object’s response using a set of equivalent magnetic dipoles distributed on a surrounding closed surface. As part of the discrimination process one must also determine the location and orientation of each buried target. This is achieved using a physics-based technique that assumes a target to be a dipole and extracts the location from the measured magnetic field vector and the scalar magnetic potential; the latter is reconstructed from field measurements by means of an auxiliary layer of magnetic charges. Once the object’s location is estimated, the measured magnetic field is matched to NSMS predictions to determine the timedependent amplitudes of the surface magnetic sources, which in turn can be used to generate classifying features. This paper shows the superior discrimination performance of the NSMS model. |
| Author(s): | F. Shubitidze, J. P. Fernandez, I. Shamatava, L. R. Pasion, B. E. Barrowes, K. O'Neill |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 1 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 907 KB |
| Title: | RFID-Based System for Pilgrims Identification and Tracking |
| Abstract: | This paper describes a prototype of a system developed using a passive RFID wristband tag for identification of pilgrims in the holy areas during Hajj. Upon presentation of the tag to a handheld reader all information related to the pilgrim holding the tag will be displayed on the screen of the reader. This way if a pilgrim gets sick, lost, or dies he can be easily identified through the tag on the spot. Officers around the holy area will have a light-weight handheld reader that can get all information from the tag without the need to burden the already overloaded communication network during the Hajj season. The developed prototype was tested on 1000 pilgrims from the country of Ivory Coast in collaboration with officials from Hajj Ministry and Development Commission of the Holy cities of Makkah and Madinah. The results of the experiment have convinced Hajj authorities to utilize this technology for all pilgrims in the future. Additionally, we have explored the possibility of tracking pilgrims using active RFID system. Due to the small number of working tags, experiment was performed only on 6 persons. Results of the latter experiment have shown that the system requires further development and needs to be validated with a larger number of tags. |
| Author(s): | M. Mohandes |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 3 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 900 KB |
| Title: | A New Software and Hardware Parallelized Floating Random-Walk Algorithm for the Modified Helmholtz Equation Subject to Neumann and Mixed Boundary Conditions |
| Abstract: | A new floating random-walk algorithm for the one-dimensional modified Helmholtz equation subject to Neumann and mixed boundary conditions problems is developed in this paper. Traditional floating random-walk algorithms for Neumann and mixed boundary condition problems have involved “reflecting boundaries” resulting in relatively large computational times. In a recent paper, we proposed the elimination of the use of reflecting boundaries through the use of novel Green’s functions that mimic the boundary conditions of the problem of interest. The methodology was validated by a solution of the one-dimensional Laplace’s equation. In this paper, we extend the methodology to the floating random-walk solution of the onedimensional modified Helmholtz equation, and excellent agreement has been obtained between an analytical solution and floating random-walk results. The algorithm has been parallelized and a near linear rate of parallelization has been obtained with as many as thirty-two processors. These results have previously been published in [1]. In addition, a GPU implementation employing 4096 simultaneous threads displayed a similar near-linear parallelization gain and a one to two orders of magnitude improvement over the CPU implementation. An immediate application of this research is in the numerical solution of the electromagnetic diffusion equation in magnetically permeable and electrically conducting objects with applications in dielectrometry and magnetometry sensors that have the ability to detect sub-surface objects such as landmines. The ultimate goal of this research is the application of this methodology to the solution of aerodynamical flow problems. |
| Author(s): | K. Chatterjee, M. Sandora, C. Mitchell, D. Stefan, D. Nummey, J. Poggie |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 4 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 229 KB |
| Title: | Iterative Solution of Electromagnetic Scattering by Arbitrary Shaped Cylinders |
| Abstract: | The electromagnetic scattering analysis of geometrically complex structure has played an important role in electromagnetic field theory and practicable applications. The fast and rigorous methods to solve such problem are in great demand. In this work, the Wave Concept Iterative Process (WCIP) combined with a coordinate transformation has been extended to the scattering problems of electromagnetic conducting square cylinder, conducting super-ellipsoid and conducting super-ellipsoid coated with thin dielectric materials. Numerical results illustrate the efficiency of our approach. The radar cross section (RCS) is then reached and compared with the literature. |
| Author(s): | J. Selmi, R. Bedira, A. Gharsallah, A. Gharbi, H. Baudrand |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 7 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 470 KB |
| Title: | Analysis of Circular Slots Leaky-Wave Antenna in Cylindrical Waveguide by Wave Concept Iterative Procedure |
| Abstract: | This paper presents the analysis of circular slots leaky-wave antenna by using an iterative method based on the wave concept. The classic method has been reformulated in cylindrical coordinates in order to be adequate for the analysis of the leaky-wave antenna with fast convergence. The proposed leaky-wave antenna can be used to replace a micro-strip patch array. Numerical results are presented to illustrate the advantages of the proposed structure. A good agreement between the new wave concept iterative procedure (WCIP) method results and published data is obtained. |
| Author(s): | Z. Houaneb, H. Zairi, A. Gharsallah, H. Baudrand |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 10 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 569 KB |
| Title: | Improving the Convergence of the Wave Iterative Method by Filtering Techniques |
| Abstract: | Among the numerical methods used in the electromagnetic modeling of high frequency electronic circuits, we include the wave concept iterative method. In this paper, we propose to improve the convergence speed of this method when modeling a complex structure. This method requires a maximum number of iterations, noted “Nmax”, to achieve the convergence to the optimal value. Our goal is to reduce the number of iterations calculated by this method to the value “Nmin” in order to reduce the computing time and to improve the convergence speed. This is done by adding a new algorithm based on filtering techniques. |
| Author(s): | H. Hrizi, L. Latrach, N. Sboui, A. Gharsallah, A. Gharbi, H. Baudrand |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 10 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 226 KB |
| Title: | Surface Integral Equation Solvers for Large-Scale Conductors, Metamaterials and Plasmonic Nanostructures |
| Abstract: | Surface integral equation (SIE) approaches for the accurate solution of different problems in computational electromagnetics are addressed. First, an efficient message passing interface (MPI)/OpenMP parallel implementation of the multilevel fast multipole algorithm-fast Fourier transform (MLFMA-FFT) is presented for the solution of large-scale conducting bodies. By combining the high scalability of the fast multipole method-FFT (FMM-FFT) with the high efficiency of MLFMA, challenging problems up to one billion unknowns are solved using a parallel supercomputer. Second, looking for the extension of these rigorous approaches to new demanded areas, the SIE method is successfully applied to the solution of left-handed metamaterials and plasmonic nanostructures. Numerical examples are presented to confirm the validity and versatility of this approach for the accurate resolution of problems in the context of leading-edge nanoscience and nanotechnology applications. |
| Author(s): | J. M. Taboada, M. G. Araújo, J. Rivero, L. Landesa, F. Obelleiro |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 2 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 961 KB |
| Title: | Efficient Analysis of Switchable FSS Structure using the WCIP Method |
| Abstract: | A precise technique based on the wave concept iterative procedure (WCIP) and a fast mode transformation (FMT) is used to adjust the frequency selective surface (FSS) response. This adjustment is achieved by integrating RF-MEMS switches. These systems use the manufacturing processes of integrated circuits. In order to initialize the iterative procedure, an incident wave is defined in spectral domain. The numerical results are compared to those obtained with the finite element method (FEM). The good agreement between simulated and published data justifies the design procedure. |
| Author(s): | N. Sboui, A. Salouha, L. Latrach, A. Gharsallah, A. Gharbi, H. Baudrand |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 3 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 751 KB |
| Title: | An Adaptive Time-Stepping Algorithm in Weakly Coupled Electro-Thermal 2D-FE Modeling |
| File Type: | Conference Paper |
| Issue: | Volume: Student Paper Competition Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 345 KB |
| Title: | Supercomputing solution of large electromagnetic problems with parallel MLFMA-FFT |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Numerical Techniques for Multiscale EM Wave Problems Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 391 KB |
| Title: | Fast Surface Integral-Equation Solutions of Metamaterial and Plasmonic Problems |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Integral Equation Methods Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 632 KB |
| Title: | Analysis and Discretization of the Yukawa-Calderon Preconditioned CFIE |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Integral Equation Methods Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 347 KB |
| Title: | An Adaptive Time-Stepping Algorithm in Weakly Coupled Electro-Thermal 2D-FE Modeling |
| File Type: | Conference Paper |
| Issue: | Volume: Multi-Physics Modeling and Simulations Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 345 KB |
| Title: | Physical Modeling of a Parasitic Net Area Check (NAC) Tie-Down Diode for De-embedding |
| File Type: | Conference Paper |
| Issue: | Volume: EM Applications in Sonnet Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 673 KB |
| Title: | E-Shaped High Gain Microstrip Patch Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Student Projects in Sonnet Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 169 KB |
| Title: | Mortar Element Method for the Integral Equation Based Modeling of Scattering by Perfect Electrical Conductors |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Integral Equation Methods Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 537 KB |
| Title: | A 60GHz Aperture-Coupled Micromachined Microstrip Antenna for Heterogeneous 3D Integration (System-In-Package) |
| File Type: | Conference Paper |
| Issue: | Volume: System-on-Package (SoP) Wireless Components Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 298 KB |
| Title: | The Method of Auxiliary Sources for Solving Low-Frequency Electromagnetic Induction Problems in Underwater Environments |
| File Type: | Conference Paper |
| Issue: | Volume: New Electromagnetic Techniques and Measurements Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 1302 KB |
| Title: | Low-Frequency Response of a Sphere Embedded in Water |
| File Type: | Conference Paper |
| Issue: | Volume: Numerical Techniques for Electromagnetic Applications Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 263 KB |
| Title: | Extraction of the Complex Permittivity of Dispersive Materials with a Stochastic Optimization Technique |
| File Type: | Conference Paper |
| Issue: | Volume: Nondestructive Evaluation and Materials Characterization Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 81 KB |
| Title: | A Parallelized Quasi-Monte Carlo Algorithm for The Extraction of Partial Inductances in IC Interconnect Structures |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Advances in Integral Equations and Fast Methods Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 196 KB |
| Title: | Physical bounds on the partial realized gain |
| File Type: | Conference Paper |
| Issue: | Volume: Small Antennas - I Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 182 KB |
| Title: | Accurate Modeling of Microwave Devices Using Space Mapping and Kriging |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Simulation-Based Modeling and Design Optimization Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 286 KB |
| Title: | Secure RFID Communications |
| File Type: | Conference Paper |
| Issue: | Volume: RFIday 2010 Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 207 KB |
| Title: | A Framework for Optimization and Statistical Analysis of On-chip Passive Devices |
| File Type: | Conference Paper |
| Issue: | Volume: Computational Electromagnetic Methods of Significantly Reduced Complexity for High-Speed IC Design Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 380 KB |
| Title: | Microwave Design Optimization Using Implicit Space Mapping with Adaptive Selection of Preassigned Parameters |
| File Type: | Conference Paper |
| Issue: | Volume: Optimization Methods for Electromagnetics Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 118 KB |
| Title: | Automated Tuning Space Mapping Implementation for Rapid Design Optimization of Microwave Structures |
| File Type: | Conference Paper |
| Issue: | Volume: Microwave Modeling and CAD Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 131 KB |
| Title: | Appropriate Choice of Trial Functions for Efficient Modeling of Asymmetric Coplanar Structures |
| File Type: | Conference Paper |
| Issue: | Volume: Microwave Modeling and CAD Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 465 KB |
| Title: | A New Parallelized Floating Random-Walk Algorithm for the Modified Helmholtz Equation Subject to Neumann and Mixed Boundary Conditions: Validation with a 1D Benchmark Problem |
| File Type: | Conference Paper |
| Issue: | Volume: Parallelized Computing for Accelerated EM Applications Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 198 KB |
| Title: | A mode selecting eigensolver for 2D FIT models of waveguides |
| File Type: | Conference Paper |
| Issue: | Volume: Fast and Efficient Methods for Transmission Lines and Waveguides Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 181 KB |
| Title: | Left-Handed Media as a Tool to Determine Scatterer Location |
| File Type: | Conference Paper |
| Issue: | Volume: Wave Propagation in Metamaterials and Nanostructures Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 93 KB |
| Title: | Normalized Surface Magnetic Source Model Applied to Camp Sibert Data Sets: Discrimination Studies |
| File Type: | Conference Paper |
| Issue: | Volume: Low-Frequency Computational Electromagnetics Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 239 KB |
| Title: | Using the Feature Selective Validation Technique to Compare Data Sets |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Numerical EM and Propagation Tools Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 655 KB |
| Title: | Breast Skin Effect on Scattered Electromagnetic Fields |
| File Type: | Conference Paper |
| Issue: | Volume: Student Paper Competition Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 495 KB |
| Title: | An hp-Adaptive Discontinuous Galerkin Method in Time Domain Applied to the Simulation of Highly Localized Current Sources |
| File Type: | Conference Paper |
| Issue: | Volume: Student Paper Competition Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 127 KB |
| Title: | Breast Skin Effect on Scattered Electromagnetic Fields |
| File Type: | Conference Paper |
| Issue: | Volume: Microwave Imaging and Inverse Problems Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 495 KB |
| Title: | Data-Derived Generalized SEA Applied to MPV TD Data |
| File Type: | Conference Paper |
| Issue: | Volume: Microwave Imaging and Inverse Problems Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 148 KB |
| Title: | Investigation of Signal Integrity in On-Chip Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: Antenna Modeling and Small Antennas Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 1244 KB |
| Title: | An hp-Adaptive Discontinuous Galerkin Method in Time Domain Applied to the Simulation of Highly Localized Current Sources |
| File Type: | Conference Paper |
| Issue: | Volume: Finite-Volume and Discontinuous Galerkin Time-Domain Techniques Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 127 KB |
| Title: | Space Mapping Optimization of Microwave Structures with FEKO |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling using FEKO – I Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 100 KB |
| Title: | Adaptive Mixed-Order FDTD Techniques on a Non-uniform Mesh |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Developments and Applications with Time-domain Modeling Techniques Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 257 KB |
| Title: | Coarse Models for Microwave Design Optimization with Space Mapping |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Optimization Methodologies for Engineering Design Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 147 KB |
| Title: | A Space Mapping Methodology for Defect Characterization |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Optimization Methodologies for Engineering Design Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 92 KB |
| Title: | Simulation of Frequency Agile RF MEMS Antennas Using WIPL-D |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling by WIPL-D Software Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 483 KB |
| Title: | Capacity of an Antenna System in the Transmission Mode with Near-field Effects |
| File Type: | Conference Paper |
| Issue: | Volume: Antenna Systems for Future Wireless Communications Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 754 KB |
| Title: | A Statistical Toolkit For Validation |
| File Type: | Conference Paper |
| Issue: | Volume: New Techniques for Computational Electromagnetic Validation Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 106 KB |
| Title: | Undergraduate Student Antenna Design Projects Using Sonnet |
| File Type: | Conference Paper |
| Issue: | Volume: Student Projects in Sonnet Number: Year: 2014 |
| Download Link: | Login To Download (For Members) File Size: 443 KB |
| Title: | Ultra Low RCS Measurement Using Doppler Frequency Shift |
| Abstract: | A new clutter removal method is proposed for ultra-low RCS measurement in anechoic chamber. In the proposed method, the target is moved along the line of sight of the radar in a sinusoidal manner. This movement generates some Doppler frequency shift. At the receiver, a filter matched to this Doppler shifter signal is implemented digitally. While the matched filter removes clutter signal largely it preserves the echo from the moving target. As it is shown through analytic estimation as well as simulations, the method can attenuate the clutter and noise level far beyond previously suggested methods. It also removes some of the difficulties in higher frequencies that exist in previous methods. |
| Author(s): | E. S. Kashani, Y. Norouzi, A. Tavakoli, P. Dehkhoda |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 1 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1618 KB |
| Title: | Two-and-half Dimension Integral Equation Method for Geophysical Electromagnetic Problems |
| File Type: | Conference Paper |
| Issue: | Volume: Detection and Imaging: Theoretical, Algorithmic, Technology and System Advances Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 170 KB |
| Title: | Transient Responses of Broadband Low Profile Filter-Antenna Under Impact of an EMP |
| File Type: | Conference Paper |
| Issue: | Volume: 10-TE-1 Electromagnetic Environment Effects and Protection II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 1071 KB |
| Title: | Transient Modeling of Magnetoelastic Problems in Electric Machinery |
| File Type: | Conference Paper |
| Issue: | Volume: Ship Propulsion System Utilizing Superconducting Components Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 651 KB |
| Title: | Towards the Synthesis of Plasmonic Nanostructures by Means of Stochastic Optimization |
| File Type: | Conference Paper |
| Issue: | Volume: Microwave Imaging and Inverse Problems Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 112 KB |
| Title: | Towards Batteryless Wearables and Implants |
| File Type: | Conference Paper |
| Issue: | Volume: S34 Wireless Implants for Biomedical Telemetry I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 731 KB |
| Title: | Time Domain Models of Negative Refractive Index Metamaterials |
| File Type: | Conference Paper |
| Issue: | Volume: Metamaterials Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 225 KB |
| Title: | Time Domain Finite Element Methods for Maxwell’s Equations in Three Dimensions |
| File Type: | Conference Paper |
| Issue: | Volume: S25 Time Domain Methods II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 324 KB |
| Title: | Through Wall Gap Detection Using Monostatic Radar |
| Abstract: | In this paper, a new experimental system for through wall gap detection and concealed vacancies behind wall is introduced. The ultra wide band (UWB) system is based on the principles of time domain reflectometry (TDR) and ground-penetrating radar (GPR) for through wall imaging to detect hidden gaps and/or hiding persons behind walls. The system uses a very short pulse generated by the vector network analyzer (VNA) to illuminate the wall under investigation through an UWB antenna probe. The detection process is achieved using time domain measurements of the probe reflection coefficient S11. Some numerical analyses have been carried out for verifying the principle of operation. The experimental results show a great ability not only for the gap detection between walls but also for estimation of the gap width with a very good accuracy (6.25 % in the worst case) for different types of walls. |
| Author(s): | A. Elboushi, A. R. Sebak, T. Denidni |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 495 KB |
| Title: | THE METHODS FOR SOLVING THE PROBLEMS OF THE DIFFRACTION OF ELECTROMAGNETIC AND ACOUSTIC WAVES USING THE INFORMATION ON ANALYTICAL PROPERTIES OF THE SCATTERED FIELDS |
| Abstract: | In spite of impressive achievements in computing technology, the study of numerical-analytical methods for solving boundary value problems in physical diffraction theory continues to be of paramount importance. This is a consequence of the fact that using such methods, we obtain a significant portion of information on solution properties at the stage of analytical investigation of the problem. This information is introduced in the problem algorithm, thus ensuring its adequacy to the problem and, consequently, its effectiveness, stability, high-performance capability etc. Conversely, ignoring the analytical solution properties results, at best, in low speed of convergence and may involve the complete loss of stability, i.e. "computation catastrophe". In this study we examine some approaches to solving boundary problems in electrodynamics and acoustics using a-priory information on analytical solution properties. [Vol. 9, No. 3 (1994), Special Issue on Generalized Multipole Technique (GMT), pp 101-111] |
| Author(s): | A.G. Kyurkchan, A.I. Sukov, A.I. Kleev, A.G. Kyurkchan, A.I. Sukov, A.I. Kleev |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 3 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 961 KB |
| Title: | The Marvels of Electromagnetic Band Gap (EBG) Structures |
| Abstract: | Artists and scientists alike have been fascinated by the existence of periodic structures in nature. When these structures interact with electromagnetic waves many unique features result. Observables are characteristics such as frequency stop-bands, pass-bands, and band-gaps. Various terminology have been used to classify these structures depending on the domain of the applications in filter designs, gratings, frequency selective surfaces (FSS), photonic crystals and band-gaps (PBG), etc. We prefer to classify them under the broad terminology of “Electromagnetic Band-gaps (EBG)”. Recently, many researchers have adopted this terminology. Broadly speaking, EBG structures are 3-D periodic objects that prevent the propagation of the electromagnetic waves in a specified band of frequency for all angles of arrival and for all polarization states of electromagnetic waves. In practice, however, it is very difficult to obtain such complete band-gap structures and partial band-gaps are achieved. Filters typically cover the scalar situation and single angle of arrival. FSS typically cover limited angles of arrival and respond differently to polarization states. PBG typically cover in-plane angles of arrival and also sensitive to polarization states. Surveying the literature, one finds that FSS terminology has been widely used in the microwave community while PBG terminology has been widely applied in the optical community. This overview paper presents a powerful computational engine utilizing Finite Difference Time Domain (FDTD) technique integrated with novel extrapolating algorithms to illustrate the marvels of EBG structures. The paper addresses structures such as (a) FSS structures, (b) PBG crystals, (c) smart surfaces for communication antenna applications, (d) surfaces with perfectly magnetic conducting properties (PMC), (e) creation of materials with negative permittivity and negative permeability, (f) surfaces with reduced edge diffraction effects and (g) reduction of mutual coupling among array antenna elements. Some representative applications of these structures are highlighted. In the last several years, there have been numerous published conference papers and journal articles dealing with the characterizations and applications of EBG structures. This paper is based on some of the results published by the author and his co-workers in the cited references. The reader is encouraged to perform detailed literature search to learn more about this area. |
| Author(s): | Y. Rahmat-Samii, Y. Rahmat-Samii |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 3 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 471 KB |
| Title: | The Floating PML Applied to Practical FDTD Applications |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 2 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 265 KB |
| Title: | THE FINITE DIFFERENCE METHOD IN MAGNETIC FIELD PROBLEMS |
| Abstract: | Finite difference techniques are widely used in the solution of electromagnetic boundary value problems, but seldom employed with static or quasi-static field problems. Historically this departure was warranted by (1) the relative ease by which problem geometries can be modeled using the finit element counterpart, and (2) the lack of symmetrical properties and large banding in the governing matrices. Presented here are some methods for generalizing the finite difference approach so that problem definition is easily modeled and Hermitian matrices result. The technique uses a conventional finite difference grid placed in the work area irrespective of the problem geometry. Finite difference equations are written in their simplest form across the problem work space. Boundary conditions are then introduced after the bulk equations are in place. The problem is solved using a non square governing matrix in a least square sense. This is accomplished most easily by premultiplying the matrix equation by its transpose. An alternative to the preconditioned conjugate gradient technique for solving the resultant matrix equation is to seek the eigenvalues for the system and express the answer as a sum of the eigenvectors. Results are shown for a salient pole motor. The technique is very useful in handling rotating or translating problems where considerable attention must be given to the proper connection and re-connection of the grid points. [Vol. 9, No. 2 (1994), Special Issue on The Numerical Computation of Low Frequency Electromagnetic Fields, pp 93-97] |
| Author(s): | Kent R. Davey, Kent R. Davey |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 2 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 407 KB |
| Title: | The Error Cross-Section Method for Quantifying the Error in Electromagnetic Scattering Problems |
| Abstract: | The Error Cross-Section (ECS) is introduced to quantify the error associated with the numerical solution of electromagnetic scattering problems. The ECS accounts for different approximations and inaccuracies in the object discretization and numerical computations. The ECS definition is based on the power conservation principle and is visualized by comparing it to the radar cross-section of a thin wire for twodimensional (2-D) problems or a small sphere for three-dimensional (3-D) problems. The proposed ECS method is independent of the adopted numerical technique and therefore can be used to give confidence in the obtained solution using several methods, such as the Method of Moments (MoM) and the Finite-Difference FrequencyDomain (FDFD) method. Application of the ECS to the optimization of certain parameters for some numerical formulations, such as the CombinedField Integral Equation (CFIE) is also presented. |
| Author(s): | A. M. Kord, I. A. Eshrah |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 4 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 348 KB |
| Title: | The Effect of Wi-Fi Radiation on the Mineralization and Oxidative Stress of Osteoblasts |
| Abstract: | Some articles reported that Wi-Fi radiation induced oxidative stress (OS) in cells and vital organs. However, the possible effects of Wi-Fi electromagnetic fields (EMFs) on bone cells have not yet been investigated. MC3T3-E1 cells were cultured in cell incubators during induced differentiation and placed 3 cm from Wi-Fi antenna. A 2.45-GHz Wi-Fi signal, transmitted between a Wi-Fi router and a laptop Wi-Fi antenna, radiated on cells for 30 min/day over a 7-day period. The two modes of the Wi-Fi irradiation were 100 mW and 500 mW. The specific absorption rates (SARs) in the cell layer by 100 mW and 500 mW Wi-Fi were 0.1671 W/kg and 0.8356 W/kg, respectively, represented as SARa and SARb, and the cell layer temperature increased by 0.065°C and 0.32°C, respectively, after 30 min of irradiation by finite difference-time domain (FDTD) simulation. The cell oxidative stress indexes were measured by a microplate reader, and the calcified nodules were examined by alizarin red S staining. At a 3-cm close range, 2.45-GHz Wi-Fi radiation increased Reactive oxygen species (ROS) and glutathione (GSH) levels in osteoblasts with the increase of irradiation time, and the quantity of mineralization slightly depended on the radiation intensity. |
| Author(s): | M. Wang, G. Yang, Y. Li, Q. Wu, Y. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 5 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1344 KB |
| Title: | The effect of numerical integration on MoM VIE solution for some isolated dielectric resonators |
| File Type: | Conference Paper |
| Issue: | Volume: Integral Equation Methods and Applications Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 937 KB |
| Title: | The behavior of smart obstacles in electromagnetic scattering: mathematical models as optimal control problems |
| Abstract: | We consider a bounded obstacle characterized by a boundary electromagnetic impedance contained in the three dimensional real Euclidean space filled with a homogeneous isotropic medium. When an incoming electromagnetic field illuminates the obstacle a scattered field is generated. A smart obstacle is an obstacle that in the scattering process, circulating a surface electric current density on its boundary, tries to achieve a given goal. We consider four possible goals: making the obstacle undetectable (i.e.: furtivity problem), making the obstacle to appear with a shape and impedance different from its actual ones (i.e.: masking problem), making the obstacle to appear in a location different from its actual one eventually with a shape and impedance different from its actual ones (i.e.: ghost obstacle problem) and finally one of the previous goals limited to a given subset of the frequency space (i.e.: definite band problems). We consider the problem of determining the optimal electric current density to achieve the given goal. The relevance in many application fields (i.e. stealth technology, electromagnetic noise control, etc.) of these problems is well known. The previous problems are modelled as optimal control problems for the Maxwell equations. Some numerical results on test problems obtained solving the optimal control problems proposed are shown. |
| Author(s): | L. Fatone, M. C. Recchioni, A.Scoccia, F. Zirilli, L. Fatone, M. C. Recchioni, A.Scoccia, F. Zirilli |
| File Type: | Journal Paper |
| Issue: | Volume: 20 Number: 2 Year: 2005 |
| Download Link: | Click here to download PDF File Size: 1965 KB |
| Title: | THE APPLICATION OF THE CONJUGATE GRADIENT METHOD TO THE SOLUTION OF OPERATOR EQUATIONS -- AN UNCONVENTIONAL PERSPECTIVE |
| Abstract: | This narrative presents an alternate philosophy for the accurate solution of operator equations, you might say "both singular and nonsingular" in general. In this approach, we try to solve the exact operator equation in an approximate way, quite differently from the matrix methods which try to solve the approximate operator equation in an exact fashion. The advantage of this new philosophy is that convergence is assured and a priori error estimates are available. The conjugate gradient methods are numerical methods which provide a means to reach this new goal, as opposed to an efficient means of just solving matrix equations, which some researchers have assumed them to be. We thereby take the position that there is a heaven-and-hell difference between the application of the conjugate gradient method to solve an operator equation and its application to the solution of matrix equations. [Vol. 2, No. 2, pp. 131-135 (1987)] |
| Author(s): | Tapan K. Sarkar, Ercument Arvas, Tapan K. Sarkar, Ercument Arvas |
| File Type: | Journal Paper |
| Issue: | Volume: 2 Number: 2 Year: 1987 |
| Download Link: | Click here to download PDF File Size: 714 KB |
| Title: | The Application of Chirp Z-Transform in Fast Computation of Antenna Array Pattern |
| Abstract: | As an essential means of evaluating antenna array performance and the basis of antenna array design, numerical computation of antenna array pattern is very important. Computation of antenna array pattern by using straightforward summation is very time consuming especially for planar array with many elements. Moreover, in some applications such as antenna array synthesis, huge number of repeated pattern computations is needed that the consumed time is intolerably long. Although the computation can be accelerated by fast Fourier transform (FFT) when the elements are equally spaced by half of a wavelength because the array factor and the element excitation currents is a Fourier transform pair, in general, FFT is not applicable. In this paper, the chirp z-transform (CZT) is introduced to accurately and efficiently compute pattern of general linear or planar antenna arrays. Numerical examples confirm that CZT is flexible, efficient, and accurate. |
| Author(s): | C. Zhang, A. Qing, Y. Meng |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 11 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1910 KB |
| Title: | Synthesizing Linear-Array Patterns via Matrix Computation of Element Currents |
| File Type: | Conference Paper |
| Issue: | Volume: Antenna Design, in memory of Stan Kubina Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 0 KB |
| Title: | Synthesizing Linear-Array Patterns via Matrix Computation of Element Currents |
| File Type: | Conference Paper |
| Issue: | Volume: Antenna Design, in memory of Stan Kubina Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 611 KB |
| Title: | Synthesis of Near Field Focused Arrays Including Far Field Constrains |
| File Type: | Conference Paper |
| Issue: | Volume: S37 Electromagnetic Techniques for the Internet of Things II Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 720 KB |
| Title: | Sub-block Decomposition Matrix Solver |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling, Design and Optimization of Complex Electromagnetic Systems Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 44 KB |
| Title: | Studies of Bi-static Scattering of Arbitrary Targets using Multiresolution Time Domain |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Finite-Difference Time Domain Modeling Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 417 KB |
| Title: | Static and Dynamic Scattering Characteristics of Complex Cavity with Rotating Blades |
| File Type: | Conference Paper |
| Issue: | Volume: 8-TP-4 In Celebration of 70th Birthday of Prof. Jia-dong Xu II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 290 KB |
| Title: | Static and Dynamic Scattering Characteristics of Complex Cavity with Rotating Blades |
| File Type: | Conference Paper |
| Issue: | Volume: 10-TE-4 In Celebration of 70th Birthday of Prof. Jia-dong Xu III Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 290 KB |
| Title: | Standardization of the Computational Methodology for Assessing Human Exposure to RF Emitters Inside and Nearby Automotive Vehicles |
| File Type: | Conference Paper |
| Issue: | Volume: Computational RF and Thermal Dosimetry Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 892 KB |
| Title: | Squint Mode MC-HRWS SAR Imaging Algorithm Based on Two-step Stolt Mapping Focus Approach |
| File Type: | Conference Paper |
| Issue: | Volume: 11-WA-4 Scattering Center Models and Their Applications Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 315 KB |
| Title: | Sparse Direct Matrix Solvers of Finite Element Discretizations in Electromagnetics |
| File Type: | Conference Paper |
| Issue: | Volume: S28 Computational Methods for Complex EM Domains, Integral Equation Methods Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 2820 KB |
| Title: | Source Localization using Reflection Omission in the Near-Field |
| File Type: | Conference Paper |
| Issue: | Volume: Technologies for Ultra-Wideband Communication Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 131 KB |
| Title: | Some Sources of Error in CEM Modeling and Simulation |
| Abstract: | |
| Author(s): | |
| File Type: | Newsletter Paper |
| Issue: | Volume: 19 Number: 2 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 112 KB |
| Title: | Some Investigations on Reflector Antenna Performance by Employing a Triple Mode Feedhorn Using FEKO |
| File Type: | Conference Paper |
| Issue: | Volume: EM Applications using FEKO I Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 740 KB |
| Title: | SOME EXAMPLES OF THE PREDICTION AND VALIDATION OF NEAR-FIELD DEPENDENT AIRCRAFT HF ANTENNA PARAMETERS USING NEC |
| Abstract: | Examples are presented of the application of a moment- method modelling procedure (using NEC) to calculate the near-field dependent parameters of aircraft HF antennas. The overall aim of the work from which the examples are drawn is to provide a 'recipe'; the application of which will generate predictions of parameters of interest which are both credible and sufficiently accurate for engineering purposes. A feature of the procedure is that no empirically derived information is incorporated. The examples encompass a range of generic aircraft and antenna types: both fixed and rotary wing airframes, and electric (wire) and magnetic (loop and notch) primary radiators. Particular emphasis is placed upon validation of the predictions. This is performed by direct measurement where possible, but where this is not practicable simple, but independent, calculations are performed based upon equivalent circuits. As for the moment-method procedure, these corroborative calculations do not depend upon empirical information. [Vol. 9, No. 1 (1994), pp 67-77] |
| Author(s): | J.W.R. Cox, J.W.R. Cox |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 1 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 970 KB |
| Title: | SOME CONSIDERATIONS ON THE USE OF NEC FOR COMPUTING EMP RESPONSE |
| Abstract: | This paper concerns the use of a frequency domain code such as the Numerical Electromagnetics Code (NEC) for computing the time domain EMP response of structures such as antennas, aircraft or communication shelters. The effects of the choice of a proper model for the excitation and of the selection of an appropriate number of frequencies for taking an inverse FFT and obtaining a correct time domain EMP response are studied. Guidelines are given for obtaining a correct time domain response with efficient use of computer time. [Vol. 4, No. 2, pp. 73-89 (1989)] |
| Author(s): | M. Dion, S. Kashyap, M. Dion, S. Kashyap |
| File Type: | Journal Paper |
| Issue: | Volume: 4 Number: 2 Year: 1989 |
| Download Link: | Click here to download PDF File Size: 544 KB |
| Title: | Some Considerations on the Reliability of Finite Element Simulators for Problems Involving Metamaterials |
| File Type: | Conference Paper |
| Issue: | Volume: Numerical Challenges in Modeling Metamaterials Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 85 KB |
| Title: | Some Advances in Shooting-Bouncing-Rays Asymptotic Propagation Methodologies |
| File Type: | Conference Paper |
| Issue: | Volume: S32 Recent Advances in Asymptotic Methods Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 179 KB |
| Title: | Simultaneous Transmit and Receive with Shared-Aperture Arrays |
| File Type: | Conference Paper |
| Issue: | Volume: S03 EM Modeling using Feko/WinProp Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 367 KB |
| Title: | Simultaneous Transmit and Receive with Shared-Aperture Arrays |
| Abstract: | An approach based on shared aperture antenna array is researched for simultaneous transmit and receive (STAR) applications. The proposed configuration is a 10×10 antenna array of circularly-polarized (CP) elements with 50 elements, somewhat sparsely distributed, dedicated for Tx while the remaining elements dedicated for Rx. The high isolation is achieved between Tx and Rx elements at the expense of higher sidelobe levels, which is an inherent property of sparse antenna arrays. To demonstrate the performance of the proposed STAR configuration, numerical modelling is conducted using multilevel fast multipole method (MLFMM) solver in Altair FEKO. |
| Author(s): | A. Samaiyar, D.-C. Son, M. A. Elmansouri, D. S. Filipovic |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1845 KB |
| Title: | Simulations of Wing Mockup Sizes for EMI Measurements using FEKO |
| File Type: | Conference Paper |
| Issue: | Volume: FEKO Modeling and Analysis - 1 Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 58 KB |
| Title: | Simulation of Implantable Miniaturized Antenna for Brain Machine Interface Applications |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in CEM Applications II Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 177 KB |
| Title: | Simulation of a Sievenpiper Artificial Magnetic Conductor using WIPL-D |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Electromagnetic Modeling by WIPL-D software II Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 582 KB |
| Title: | Simulation for Several Kinds of TEM Horn Antenna Used by NEMP Simulator |
| File Type: | Conference Paper |
| Issue: | Volume: 1-P1-C Wideband and Multiband Antennas Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 355 KB |
| Title: | Simulation Driven Process for Co-existence and Interference Issues in Electronic Devices |
| File Type: | Conference Paper |
| Issue: | Volume: S09 Low-Frequency Computational Electromagnetics Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 366 KB |
| Title: | SIMPLE FINITE ELEMENT SOLUTIONS FOR EDDY CURRENT LOSSES IN PIPE-TYPE CABLES |
| Abstract: | This paper outlines a simple finite element approach for computing eddy current losses in pipe-type cables Essentially, what is solved for is the eddy current loss in a metallic shell that encompasses one or more power frequency currents, flowing parallel to the longitudinal axis of the shell. The traditional cross sectional model for this type of problem involves an open boundary, which can present difficulties for conventional finite element methods, although some success has recently been reported with asymptotic boundary conditions [1]. For many practical cases, the simplest way to bypass this obstacle is to impose an approximate boundary condition, H= 0, at the outer surface of the metal shell It is demonstrated in this paper that this approximate boundary condition is quite accurate if the shell is, as a rule of thumb, at least three skin depths thick. [Vol. 10, No. 2 (1995), pp 102- 109] |
| Author(s): | T. Loga, F.S. Chute, F.E. Vermeulen, T. Loga, F.S. Chute, F.E. Vermeulen |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 2 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 805 KB |
| Title: | Shape Optimization of the Momentum Ring Cross Section for Satellite Attitude Control Based on Magnetohydrodynamics |
| Abstract: | Compared with the traditional actuator, the fluid momentum controller actuator based on magnetohydrodynamics (MHD) has some unique advantages and characteristics. In this paper, a method is proposed for the shape optimization of fluid momentum ring cross section. Based on the engineering situation, this article proposes a mathematical model of angular momentum that can be used for analytical calculations. Second, the two shapes obtained are unified and mathematically expressed in terms of maximum power and minimum resistance, respectively. Finally, the particle swarm algorithm is used to optimize the parameters of the proposed shape in combination with finite element method (FEM). Compared with the common rectangular section scheme, the attitude adjustment performance of fluid momentum ring can be effectively improved. Specifically, for the same area of cross section, the fluid momentum rings with the proposed shape provide the angular momentum values that exceed those of the rectangular shape by 14%-17% for the cases considered. This method avoids the huge computation of computational fluid dynamics and multidisciplinary topology optimization. |
| Author(s): | Y. Gu, Q. Liang, S. Wang, A. Zhou, C. Liu |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 3 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 1525 KB |
| Title: | Selection of New Features in the Electromagnetic Solution Kernel of FEKO Suite 6.0 |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Simulation using FEKO Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 576 KB |
| Title: | SELECTING WIRE RADIUS FOR GRID/MESH MODELS |
| Abstract: | Conducting bodies such as antennas and scatterers can be modelled by thin wire segments. However, a generally accepted and consistent criteria for selecting optimum radius for the wire segments in the model has yet to be specified. This paper presents some results rom modelling microstrip patch antennas with thin wires and the effects of wire radius on the resonance characteristics of the antenna. [Vol. 5, No. 2, pp. 43- 57 (1990)] |
| Author(s): | L. A. Oyekanmi, J. Watkins, L. A. Oyekanmi, J. Watkins |
| File Type: | Journal Paper |
| Issue: | Volume: 5 Number: 2 Year: 1990 |
| Download Link: | Click here to download PDF File Size: 485 KB |
| Title: | Selecting Genetic Algorithm Operators for CEM Problems |
| File Type: | Conference Paper |
| Issue: | Volume: Computational Techniques Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 285 KB |
| Title: | Scattering matrix descriptors of Trefftz finite elements |
| File Type: | Conference Paper |
| Issue: | Volume: Higher Order Methods Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 138 KB |
| Title: | Scattering from Large-Scale Stratified Rough Surfaces using Improved BMIA/CAG |
| Abstract: | A numerical method is presented to analyze the scattering behavior of large-scale stratified rough surfaces. The method improves the banded matrix iterative approach / canonical grid (BMIA/CAG) by adopting some simple formulas to calculate the coupling interactions between different surfaces. Such treatment reduces the complexity of the method at expense of little accuracy when the roughness of surfaces can be ignored compared to the distance between surfaces, and also reduces the computation time by parallel implementation technique. Based on emissivity calculation, the one-dimensional method is proven to be effective for the analysis of some scattering properties. Then the proposed method is compared with the method of moments (MoM) by example of multilayered lunar regolith. Details of numerical results are given and discussed, which provide a guide in the application of the improved method. |
| Author(s): | L. He, L. Lang, Q. Li, W. Zheng |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 692 KB |
| Title: | Scattering from an Arbitrarily Shaped Three-Dimensional Inhomogeneous Magnetic and Dielectric Scatterer |
| File Type: | Conference Paper |
| Issue: | Volume: Integral Equation Methods and Applications Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 1091 KB |
| Title: | Scattering cross sections of smart obstacles |
| File Type: | Conference Paper |
| Issue: | Volume: Challenges in Scattering, Radiation and Multi-domain Modeling Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 137 KB |
| Title: | Scattering and Diffraction Evaluated by Physical Optics Surface Current on a Truncated Cylindrical Conductive Cap |
| Abstract: | In this study physical optics (PO) surface current is obtained by using the Malyughinetz solution to get the scattered field expression for a truncated cylindrical conductive cap satisfying the related boundary conditions given throughout this paper. This is done by using the inverse edge point method for the transformation from the Malyughinetz solution for the wave diffraction by a half plane to the wave diffraction by a truncated conductive cylinder. This transformation method can be used to examine the diffraction and scattering phenomena for curved surfaces having discontinuities as dealt with in this work. Total scattered field comprising the incident and scattered fields is plotted with respect to the observation angle for some parameters of the problem. The obtained results are examined numerically for the same parameters. |
| Author(s): | M. Kara, M. Mutlu |
| File Type: | Journal Paper |
| Issue: | Volume: 38 Number: 5 Year: 2023 |
| Download Link: | Click here to download PDF File Size: 293 KB |
| Title: | S-Slot Dual-Fed Tri-Band Square Patch Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Student Projects in Sonnet Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 0 KB |
| Title: | S-Slot Dual-Fed Tri-Band Square Patch Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: Student Projects in Sonnet Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 467 KB |
| Title: | Robust Adaptive Beamforming Based on Fuzzy Cerebellar Model Articulation Controller Neural Network |
| Abstract: | To solve the problem of degraded adaptive beamforming performance of smart antenna caused by array steering vector mismatch and array manifold errors, a robust beamforming algorithm based on Fuzzy Cerebellar Model Articulation Controller (FCMAC) neural network is proposed. The proposed algorithm is based on explicit modeling of uncertainties in the desired signal array response and a FCMAC neural network. The calculation of the optimal weight vector is viewed as a mapping problem, which can be solved using FCMAC neural network trained with input/output pairs. Our proposed approach provides excellent robustness against some types of mismatches and keeps the mean output array SINR consistently close to the optimal value. Moreover, the FCMAC neural network avoids complex matrix inversion operations and offers fast convergence rate. Simulation results show that the proposed algorithm can significantly enhance the robustness of the beamformer in the presence of array steering vector mismatch and array manifold errors, and the output performance is superior to the current methods. |
| Author(s): | J. Yu, P. Fan, C. Li, X. Lu |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 5 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2245 KB |
| Title: | Rigorous Investigation of Induced Fields on Different Parts of a Typical PCB Exposed to External Radiation |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced EMC Modeling Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 108 KB |
| Title: | RFIC Test Board Design and Modeling using Sonnet |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Simulations using Sonnet Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 1549 KB |
| Title: | Reusable wearable patch antenna for health monitoring body area sensor networks |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling of RFID Devices and Systems Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 344 KB |
| Title: | Resonant Nanoantennas for Enhancing the Interaction of Terahertz Radiation with Nanomaterials |
| File Type: | Conference Paper |
| Issue: | Volume: S12 Design, Analysis and Applications of EM Metasurfaces II Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 163 KB |
| Title: | Research on Workflow of Improving Electromagnetic Compatibility of Search and Rescue Helicopter |
| File Type: | Conference Paper |
| Issue: | Volume: S17 Uncertainty Quantification in CEM Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 677 KB |
| Title: | Research on the FDTD Method of Scattering Effects of Three Dimensional Dusty Plasma |
| File Type: | Conference Paper |
| Issue: | Volume: 4-3-A Advances in FDTD Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 324 KB |
| Title: | Research and Experiments on Anti-UAV Technology |
| Abstract: | Unregistered flight of Unmanned Aerial Vehicle (UAV) has been a severe challenge to the security of low-altitude airspace. Illegal elements may use UAV to carry dangerous goods or steal privacy. More and more conferences and large-scale activities pay attention to the security and privacy of the air defense. This paper focuses on two kinds of UAV interference solutions, traditional full-band suppression and targeted spectrum suppression. Experiments show that the target spectrum suppression scheme can reduce 4.61dB transmission power compared with traditional full-band suppression for a certain UAV at the same attack distance. The novelty of paper is that we use artificial intelligence method to analyze the spectrum of UAV signal and the new scheme can reduce power transmission by more than half at the same attack distance. This paper also carry out comparative experiments on different types of UAVs, demonstrating its excellent performance. In addition, for some WiFi UAVs, this paper can even steal their password to acquire the UAVs' control. |
| Author(s): | H. Wei, X. Wang, X. Shi, B. Liang |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 5 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 21801 KB |
| Title: | Reformulation of the Nonstandard Yee Algorithm to Reduce Error on Dielectric Boundaries |
| File Type: | Conference Paper |
| Issue: | Volume: Non-Standard FDTD Methods Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 95 KB |
| Title: | Reduction of Coupling between Flush-Mounted Antennas |
| Abstract: | This paper discusses some numerical aspects of the coupling study between two flush-mounted antennas. It is shown that a bed of nails embedded between flush-mounted quad-ridge horns separated by 20 cm (4 lambda 6 GHz) edge-to-edge greatly reduces coupling by about 17 dB at lower frequency end, where the electrical distance between antennas is the shortest. The considered antenna system operates from 6-19 GHz and has |S11| < -10 dB, and coupling < -60 dB. The numerical modelling is carried out using MoM and FEM solvers. The computed results are in good agreement with measurements. |
| Author(s): | P. V. Prasannakumar, M. A. Elmansouri, M. Ignatenko, D. Filipovic |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 10 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1853 KB |
| Title: | Reduction of Coupling between Flush-Mounted Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: S23 EM Modeling Using FEKO I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 415 KB |
| Title: | Reconstruction the Orbital Velocity Field of Ship Wake by the Least Square Method |
| File Type: | Conference Paper |
| Issue: | Volume: 7-TA-4 In Celebration of 70th Birthday of Prof. Jia-dong Xu I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 461 KB |
| Title: | Recent Extensions in FEKO: FEM Excitations, Cable Coupling, and Ideal Receiving Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: FEKO Modeling and Analysis Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 323 KB |
| Title: | Recent Advances in HFSS for Electromagnetic Radiation and Scattering Analysis |
| File Type: | Conference Paper |
| Issue: | Volume: In Tribute To Dr. Zoltan Cendes Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 1152 KB |
| Title: | Receiving Mode Simulations for Ultra-Wideband Characterization of Small Antenna Arrays and a Novel Look on Mutual Coupling |
| File Type: | Conference Paper |
| Issue: | Volume: Student Paper Competition Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 469 KB |
| Title: | Receiving Mode Simulations for Ultra-Wideband Characterization of Small Antenna Arrays and a Novel Look on Mutual Coupling |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Modeling and Simulation Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 469 KB |
| Title: | Quasi-peak---one of Sensitive Parameters of Electromagnetic Interference in Communication Equipment |
| File Type: | Conference Paper |
| Issue: | Volume: 3-4-E Electromagnetic Environment Effects II Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 208 KB |
| Title: | Quantifying EMC Measurement Accuracy Using Feature Selective Validation |
| Abstract: | It is commonplace in the field of Computational Electromagnetics (CEM) for engineers to validate models against experimental results. In some cases, this is performed with little understanding about the accuracy of the experimental data used to validate the underlying calculations from which Electromagnetic models are formed. This paper therefore explores the accuracy and more importantly the areas of inaccuracy and variability that may be associated with experimental data. The Feature Selective Validation (FSV) method is used to assess each area of variability, and thus quantify the quality of test configurations and test samples. In examining experimental repeatability rather than comparison to electromagnetic analysis results, this paper concludes that, while substantial variation between experimental results can exist, the use of FSV provides considerable assistance in quantifying repeatability and therefore assigning confidence to measurements against which CEM results can be compared. While this paper is based on experience in the automotive sector, it is anticipated that these findings are more widely applicable. |
| Author(s): | A. Denton, A. Martin, A. Duffy, A. Denton, A. Martin, A. Duffy |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 1 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 476 KB |
| Title: | Quantifying EMC Measurement Accuracy Using Feature Selective Validation |
| File Type: | Conference Paper |
| Issue: | Volume: New Techniques for Computational Electromagnetic Validation Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 818 KB |
| Title: | Quad-band Compact MIMO Antennas for 5G Mobile Communications |
| Abstract: | Three types of quad-band millimetric-wave two-port MIMO antenna systems are proposed for the forthcoming generations of mobile handsets. A novel printed antenna is introduced to be the single element of the proposed MIMO antennas. It is shown that the proposed MIMO antennas are capable of producing both spatial and polarization diversities that enhance the performance of mobile communications. Two configurations of co-polarized two-port MIMO antennas are proposed to provide spatial diversity, whereas a cross-polarized two-port MIMO antenna is proposed to produce polarization diversity. It is shown that all the proposed MIMO antennas can operate efficiently over the four frequency bands centered at 28, 43, 52, and 57 GHz. Prototypes are fabricated for the proposed MIMO antennas for the sake of experimental evaluation. The measurements agree with the simulation results showing high performance of the proposed types of MIMO antennas including the impedance matching, radiation patterns, envelop correlation coefficient, and diversity gain. Both the experimental and simulation results show that the achieved bandwidths, at the four operational frequency bands, are 0.6, 0.6, 1.8, and 1.5 GHz, respectively. Also, the radiation efficiencies calculated at the four operational frequencies are 86.5%, 87.5%, 89.2%, and 90.0%, respectively. The dimensions and the results concerning the performance of the proposed MIMO antennas are compared to other designs for MIMO antennas available in some recently published work. |
| Author(s): | A. E. Farahat, K. F. A. Hussein |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 8 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 11715 KB |
| Title: | Provably Stable Local Application of Crank-Nicolson Time Integration to the FDTD Method with Nonuniform Gridding and Subgridding |
| Abstract: | This contribution removes some doubts about the stability issues associated with the local and anisotropic use of Crank-Nicolson (CN) time integration in Finite-Difference Time- Domain (FDTD) simulations with spatial irregularities such as nonuniformity and subgridding. |
| Author(s): | A. Van Londersele, D. De Zutter, D. Vande Ginste |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 10 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1419 KB |
| Title: | Provably Stable Local Application of Crank-Nicolson Time Integration to the FDTD Method with Nonuniform Gridding and Subgridding |
| File Type: | Conference Paper |
| Issue: | Volume: S32 Advancted FDTD Methods Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 160 KB |
| Title: | Pros and Cons of Microwave Imaging Techniques for the Reconstruction of Velocity Profiles of Cylindrical Targets in Axial Motion |
| File Type: | Conference Paper |
| Issue: | Volume: S51 Inverse Scattering Techniques for GPR and Subsurface Imaging Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 70 KB |
| Title: | Propagating and Scattering of the Electromagnetic Vortex Generated by a Spiral Parabolic Antenna |
| Abstract: | A modified octree grouping scheme of the multilevel fast multipole algorithm (MLFMA) is proposed to analyze the electromagnetic (EM) scattering from the electrically large target, which is illuminated by a spiral parabolic antenna. The spiral parabolic antenna is used to generate the electromagnetic vortex of a specific mode number by adjusting the height of split. The proposed method builds two octree groups and decouples the interaction between the antenna and the target, so as to save the computational resource and improve the computational efficiency. Using this scheme, the numerical example with double metal spheres illuminated by the electromagnetic vortex reveals some special phenomena due to the spiral phase distribution, while the example with a scaled-down airplane at long operating range demonstrates that the electromagnetic vortex tends to be plane wave locally with the increase of propagation distance. |
| Author(s): | B. H. Yin, Z. He, R. S. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 11 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1572 KB |
| Title: | Project Based Microwave Filter Design Courses |
| File Type: | Conference Paper |
| Issue: | Volume: CEM for EM Education Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 234 KB |
| Title: | Progress in Developing Custom Cubature Rules for Computational Electromagnetics |
| File Type: | Conference Paper |
| Issue: | Volume: S59 Frequency and Time Domain Integral Equation Solvers II Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 155 KB |
| Title: | Predictions of Transient Eddy Current Fields Using Surface Impedances in Shell Structures |
| Abstract: | The surface impedance techniques have been discussed with moderate interest over the past fifteen years [1 - 6]. They are approached as a means to express sinusoidal fields by yielding a Neuman condition on the surface of conductors. They are generally applied when the skin depth is much less than the thickness characterizing conductor thicknesses within the problem. Some discussion has been given to their utilization near corners and slots [3]. They are not generally used as a means of approaching transient problems. The main focus of this work is in their utilization both in steady state and transient problems, primarily for shell type structures. |
| Author(s): | K. Davey, L. Turner, K. Davey, L. Turner |
| File Type: | Journal Paper |
| Issue: | Volume: 4 Number: 1 Year: 1989 |
| Download Link: | Click here to download PDF File Size: 601 KB |
| Title: | Position Deviation Evaluation for UAV Inspecting Overhead Transmission Line Based on Measured Electric Field |
| Abstract: | Unmanned aerial vehicle (UAV) used in overhead transmission lines (OTLs) inspection are required to fly along a preset path to conduct special tasks. However, UAVs sometimes deviate from the preset path due to positioning error or control error in practice, thereby reducing the quality of the inspection task or even leading to serious line collision accidents. In this study, a method is proposed to evaluate the UAV position deviation from the preset path in real time on the basis of a measurement and analysis on the electric field generated by transmission lines. A new idea is presented to solve the obstacle avoidance problem for UAV in transmission line inspection. To improve evaluation accuracy, the influences of transmission tower and UAV body are considered in the theoretical calculation model for electric field, and the electric field data are preprocessed to diminish the influence of environmental noise and measurement inherent error. To improve the real-time performance of the evaluation algorithm, the dynamic programming and hidden Markov model (HMM) are combined to form a dynamic-hidden Markov model algorithm, in which the parameters of the HMM are determined by the expected maximization parameter estimation and corrected in real time. The feasibility and accuracy of the proposed method are verified by several simulation examples and experiments. |
| Author(s): | D. Xiao, Q. Zheng, J. Lei, S. Liu |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 4 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1707 KB |
| Title: | Polyethylene Pipeline Detection and Visualization Using the Method of Auxiliary Sources |
| File Type: | Conference Paper |
| Issue: | Volume: S21 Low Frequency Applications Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 243 KB |
| Title: | PILGRIMS PROGRESS - LEARNING TO USE THE NUMERICAL ELECTROMAGNETICS CODE (NEC) TO CALCULATE MAGNETIC FIELD STRENGTH CLOSE TO A SOMMERFELD GROUND |
| Abstract: | This paper gives the history and a description of work performed by the authors to identify some errors and solve some problems involved in the use of the Numerical Electromagnetics Code (NEC2 and NEC3, with the companion code SOMNEC) to calculate H-fields in the vicinity of a Sommerfeld ground, and describes some of the code errors and omissions that have been identified to date. The most significant discovery has been that a section of code has been omitted from the subroutine NHFLD in NEC2, which results in incorrect calculations by NEC2 of near H-field strengths close to a real ground. It must be noted that Macfarlane, Fleming, and Iskra, have access to NEC2 only, whilst k has access to both NEC2 and NEC3. [Vol. 5, No. 2, pp. 58-75 (1990)] |
| Author(s): | Ian P. Macfarlane, A. H. J. Fleming, Steve Iskra, Greg Haack, Ian P. Macfarlane, A. H. J. Fleming, Steve Iskra, Greg Haack |
| File Type: | Journal Paper |
| Issue: | Volume: 5 Number: 2 Year: 1990 |
| Download Link: | Click here to download PDF File Size: 849 KB |
| Title: | Phase-Only Synthesis of Convex Metallic Reflectarray Antennas for Multi-beam Radiations via Steepest Descent Method |
| File Type: | Conference Paper |
| Issue: | Volume: S33 Electromagnetic Techniques for the Internet of Things I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 950 KB |
| Title: | PERFORMANCE OPTIMIZATION OF AN INTEGRAL EQUATION CODE FOR JET ENGINE SCATTERING ON CRAY-C90 |
| Abstract: | The numerical solution of Maxwell’s equations is a computationally intensive task and use of high-performance parallel computing facilities is necessary for the larger class of practical problems in scattering, propagation and antenna modeling. It is therefore necessary to carefully consider algorithm optimizations aimed at improving the code’s run time performance on the computing platform employed. Although some performance improvement can be derived from compiler-level optimizations, further speed-up may involve manual effort in algorithm restructuring, data layout, and parallelization. This paper focuses on the manual optimizations used to improve the performance of a moment method code for the analysis of a cylindrically periodic structure, as is the case with a jet engine. We describe the steps taken which resulted in nearly two orders of magnitude improvement over the original version of the code. A 16-processor shared-memory CRAY-C90 vector supercomputer was employed. Our optimization took advantage of SSD its solid-state storage, enabled better loop vectorizations, parallelized the matrix_fill routine, and called appropriate CRAY-C90 library routines |
| Author(s): | Mikhail Smelyanskiy, Edward S. Davidson, John L. Volakis, Mikhail Smelyanskiy, Edward S. Davidson, John L. Volakis |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 2 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 868 KB |
| Title: | Performance Comparison between Rigorous and Asymptotic Techniques Applied to the Analysis of Wind Turbines |
| Abstract: | The scattering field analysis of wind turbines using asymptotic and rigorous techniques is presented. Several simulations considering different configurations and frequencies are conducted to compare the performance of the electromagnetic techniques. These predictions are very useful for studying the influence of wind farms in terrestrial radio systems. On the other hand, not only a static analysis has been done but also a study of the scattered fields when the blades are in movement. The Doppler effect due to the blade movement has been taken into account to achieve some simulation results. Modules FASANT and MONURBS of NEWFASANT computer tool have been used. FASANT is based on the geometrical theory of diffraction (GTD) on its uniform theory of diffraction (UTD) formulation and MONURBS is based on the method of moments (MoM) and physical optics (PO). A comparison of the results obtained with both codes is shown, as well as the CPU-time and computer memory required. |
| Author(s): | A. Tayebi, J. Gómez, I. González, L. Lozano, M. Jesús Algar, E. García, Í. Etayo, F. Cátedra |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 2 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 696 KB |
| Title: | Performance Analysis of Outer Rotor Wound Field Flux Switching Machine for Direct Drive Application |
| Abstract: | One of the premium in-wheel applications is direct drive, evolving enormously for HEV’s. An alternative and lot of research especially on the outer rotor field excitation flux switching machine is required to overcome the problems like demagnetization and high cost of rare earth magnetic material used in interior permanent magnet synchronous machine (IPMSM). Salient rotor pole and non-overlapping winding embedded in electrical machine design possess some pertinent features such as; reduce copper losses, low-cost, and usage in high speed applications. Therefore, this paper emphasizes on the design of three-phase outer rotor wound field FSM employing optimization, performance analysis and MEC models of proposed 12-slot/13-pole FSM corresponding to different rotor positions are combined as GRN and are solved utilizing incidence matrix methodology using MATLAB. Moreover, FSM flux behavior, no-load, and load analysis were examined using JMAG software and based on FEA. Results obtained from GRN methodology and corresponding FEA results close resemblance with and errors less than ~1.2%, hence validating accuracy of GRN methodology. The proposed design for hybrid electric vehicle torque characteristic is compared with existing IPMSM and 6-slot/7-pole non-overlapping stator wound flux switching machine (NSWFS). |
| Author(s): | N. Ahmad, F. Khan, N. Ullah, M. Z. Ahmad |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 8 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2430 KB |
| Title: | Pattern Analysis of Conformal Antenna Arrays via the Characteristic Modes of Isolated Elements |
| Abstract: | A simple pattern analysis method is presented for conformal antenna arrays, considering mutual coupling effects based on the characteristic modes of isolated elements. There are many methods to analyze the performance of conformal antenna arrays, but they seldom provide a clear insight into the coupling mechanism. Thus, the overall characteristic modes of the conformal array are calculated from the characteristic modes of the isolated elements and coordinate transformation, which are different from the traditional modal analysis for the entire array. And the radiation field of the conformal array is given. The modal coupling matrix which depends on the structural parameters and relative pose of conformal elements is used to characterize the mutual coupling effect between elements and explain the coupling mechanism from the perspective of the characteristic currents. Finally, the effectiveness and efficiency of the proposed method is verified by some numerical examples. |
| Author(s): | Y. Zeng, S. Zhang, S. Lou |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 557 KB |
| Title: | Particle-In-Cell methods for modeling electromagnetic propagation in plasmas |
| File Type: | Conference Paper |
| Issue: | Volume: S39 Modeling Electromagnetic Waves in Plasma Environments Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 683 KB |
| Title: | PARTIAL SURVEY OF CODES FOR HIGH FREQUENCY SCATTERING FROM FACET MODELS OF RADAR TARGETS |
| Abstract: | In this work, four high-frequency electromagnetic scattering codes are surveyed with regard to their capabilities and limitations for the calculation of the radar cross section (RCS) of facet models of targets. The codes discussed are MISCAT, NRCPTD, McPTD, and Xpatch. All of these codes utilize the physical theory of diffraction (PTD) to approximate the field scattered from the target. A short discussion of the modeling features of each code is given and some sample numerical results are generated. It is concluded that, of the models considered here, Xpatch possesses the most comprehensive modeling features available, with no loss in accuracy over the other codes. [Vol. 9, No. 2 (1994), pp 142-153] |
| Author(s): | Michael A. Richards, Michael A. Richards |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 2 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 1233 KB |
| Title: | Parametric Investigation and Analysis of an Electric-LC Resonator by Using LC Circuit Model |
| Abstract: | Electric-LC resonators (ELCs) metamaterials, as a kind of common structures, have been extensively investigated from microwave to terahertz frequencies. In this paper, we present a LC circuit model to analyze electric-LC resonator. With the reliable and closed formulas of the effective inductance and capacitance, the expressions of electric and magnetic resonance frequencies were obtained, which is suitable to discuss the resonance characteristic under the normal incidence case. Meanwhile, the mutual relationships among the permittivity, permeability, refractive index, and structure parameters can be explored by using the obtained expressions. Numerical simulations and theoretical calculations reveal that the width and length of the gaps are some of the critical parameters determining the resonator frequency of the example metamaterial. This study provides valuable information for designing the desired left-hand metamaterial at some specific frequency points. |
| Author(s): | H. Xiong, X.-M. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 10 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1510 KB |
| Title: | Parametric Analysis of Vertical Incidence Reflectivity of Conformal PML |
| File Type: | Conference Paper |
| Issue: | Volume: 4-2-E EM Theory I Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 325 KB |
| Title: | Parallel Integral Equation Based Non-overlapping DDM for Fast Solving Electromagnetic Scattering Problems with Changeable Parts |
| Abstract: | In this paper, a parallel non-overlapping domain decomposition method (DDM) using electric field integral equation (EFIE) is proposed for fast and accurate analysis of electrically large PEC objects with changeable parts in the condition of limited resources. The approach has considered that there are null fields as well as electric current inside a metal object in the original problem, then a novel transmission condition similar to an absorbing boundary is adopted, hence the continuity of electric currents is enhanced and the convergence is further improved in the outer iterative procedure. Moreover, the coupling between different subdomains is calculated in the manner of near field to avoid the storage of the mutual impedance. Some numerical examples are given to demonstrate the efficiency and stability of the proposed method. |
| Author(s): | Z. Gu, X. Zhao, C. Zhai, Z. Lin, Y. Zhang, Q. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 6 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2056 KB |
| Title: | Overview of the Latest Electromagnetic Solver Featuers in FEKO Suite 7.0 |
| File Type: | Conference Paper |
| Issue: | Volume: S16 EM Modeling using FEKO Number: Year: 2015 |
| Download Link: | Login To Download (For Members) File Size: 330 KB |
| Title: | Overview of Recent Extensions in the Electromagnetics Computer Code FEKO and their Application |
| File Type: | Conference Paper |
| Issue: | Volume: Applications of FEKO Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 740 KB |
| Title: | Optimization of Loneys Solenoid Design Using a Dynamic Search Based Technique |
| Abstract: | Particle swarm optimizer is one of the searched based stochastic technique that has a weakness of being trapped into local optima. Thus, to tradeoff between the local and global searches and to avoid premature convergence in PSO, a new dynamic quantumbased particle swarm optimization (DQPSO) method is proposed in this work. In the proposed method a beta probability distribution technique is used to mutate the particle with the global best position of the swarm. The proposed method can ensure the particles to escape from local optima and will achieve the global optimum solution more easily. Also, to enhance the global searching capability of the proposed method, a dynamic updated formula is proposed that will keep a good balance between the local and global searches. To evaluate the merit and efficiency of the proposed DQPSO method, it has been tested on some well-known mathematical test functions and a standard benchmark problem known as Loney’s solenoid design. |
| Author(s): | S. Tu, O. U. Rehman, S. U. Rehman, S. U. Khan, M. Waqas, A. Farooq |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 1 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1586 KB |
| Title: | Optimization of Interior Permanent Magnet Motor on Electric Vehicles to Reduce Vibration Caused by the Radial Force |
| Abstract: | The vibration and noise level of a driven motor on electric vehicles has a great influence on the overall comfort of the whole vehicle. In this paper, the main vibrational harmonic waves with high amplitudes of Interior Permanent Magnet (IPM) motor were investigated via an experiment. In order to lower the amplitudes of these harmonic waves, the paper carries out the optimization of radial force of the IPM motor based on the parameter sensitivity analysis and also implemented the structural optimization, according to the dynamic response of the stator. The final dynamic simulation of the optimized model excited by the optimized radial force, show that the optimization results in a better performance of the vibration behaviors. This study could provide some guidelines for the optimal design of the interior permanent magnet motor to reduce vibration. |
| Author(s): | L. Y. Xiang, S. G. Zuo, L. C. He, M. H. Zhang, J. J. Hu, G. Long |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 4 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 550 KB |
| Title: | Optimization Design of Electromagnetic Devices Using an Enhanced Salp Swarm Algorithm |
| Abstract: | An Enhanced version of the Salp Swarm Algorithm (SSA) referred to as (ESSA) is proposed in this paper for the optimization design of electromagnetic devices. The ESSA has the same structure as of the SSA with some modifications in order to enhance its performance for the optimization design of EMDs. In the ESSA, the leader salp does not move around the best position with a fraction of the distance between the lower and upper bounds as in the SAA; rather, a modified mechanism is used. The performance of the proposed algorithm is tested on the widely used Loney’s solenoid and TEAM Workshop Problem 22 design problems. The obtained results show that the proposed algorithm is much better than the initial one. Furthermore, a comparison with other well-known algorithms revealed that the proposed algorithm is very competitive for the optimization design of electromagnetic devices. |
| Author(s): | H. R.E.H. Bouchekara, M. K. Smail, M. S. Javaid, S. I. Shamsah |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 12 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1488 KB |
| Title: | On the Origin of the Addition Theorem and its Role in Multipole Expansions |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Computational Techniques in Electromagnetics - 2 Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 212 KB |
| Title: | ON THE FUNCTIONING OF A HELICOPTER-BORNE HF LOOP ANTENNA |
| Abstract: | Numerical techniques allow engineers to evaluate the performance of antennas on complex structures. These techniques can provide valuable physical insights into the overall functional performance of such antennas. This short paper reports on the use of NEC2 to investigate the radiation characteristics of a loop antenna mounted below the tailboom of a helicopter in the frequency band 2AE15 MHz. It was concluded that such a loop antenna serves mainly to excite a dominant electrical dipole mode of operation for frequencies less than the lowest natural electrical resonance frequency of the helicopter itself, but greater than some frequency near the low end of the HF band. A limited set of measurements performed on a scale model of a helicopter generally supports the conclusions drawn from the numerical results predicted using NEC2. The reported result is of importance in so-called 'nap-of- the-earth' HF communications from helicopters. [Vol. 6, No. 2, pp. 53-73 (l99l)] |
| Author(s): | Duncan C. Baker, Duncan C. Baker |
| File Type: | Journal Paper |
| Issue: | Volume: 6 Number: 2 Year: 1991 |
| Download Link: | Click here to download PDF File Size: 1130 KB |
| Title: | ON THE COMPARISON OF NUMERICAL METHODS |
| Abstract: | Serious comparisons of numerical methods are important for scientists who develop new codes as well as for those who use programs. Historical considerations show some errors which were made in the past and should be avoided in the future. Every numerical code is based not only on numerical but also on analytical considerations. Both of them have to be taken into account. As a result, benchmarks for complicated topics (numerical calculations of electromagnetic fields) should give more information than just numbers like 'speed', 'memory requirement', etc. [Vol. 3, No. 2, pp. 79-82 (1988)] |
| Author(s): | Ch. Hafner, Ch. Hafner |
| File Type: | Journal Paper |
| Issue: | Volume: 3 Number: 2 Year: 1988 |
| Download Link: | Click here to download PDF File Size: 508 KB |
| Title: | On an Antenna Design for 2D Scalar Near-Field Microwave Tomography |
| Abstract: | Some desired antenna specifications for performing two-dimensional (2D) transverse magnetic (TM) microwave tomography imaging are presented and discussed. These desired specifications are governed by the need to reduce the discrepancy between the 3D measurement configuration and the utilized 2D TM inversion algorithm, as well as the desire to enhance the achievable image accuracy and resolution. Driven by these specifications, an existing compact ultrawideband antenna element is modified. These modifications attempt to make the near-field distribution of this antenna more focused in the two orthogonal planes in the forward near-field zone of the antenna, while keeping its physical size relatively small and maintaining multiple frequencies of operation for this antenna. The final antenna has a physical size of 26×29×38.5 mm3 and can operate at two different frequency bands (2.34-5.04 GHz and 8.06-13 GHz based on the |S11| ?-8 dB impedance bandwidth definition). The measured near-field distribution of this antenna is presented in the imaging plane and the plane perpendicular to the imaging plane. |
| Author(s): | N. Bayat, P. Mojabi |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 2827 KB |
| Title: | Numerical Radar Cross Section Simulation and Analysis of Complex Targets in FEKO |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling using FEKO – I Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 230 KB |
| Title: | Numerical Implementation of the Array Scanning Method (ASM) for 2DPeriodic Materials |
| File Type: | Conference Paper |
| Issue: | Volume: Modeling and Applications of Microwave Metamaterial Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 83 KB |
| Title: | Numerical Dispersion in the Alternate-Direction-Implicit Finite-Difference Time-Domain Method |
| File Type: | Conference Paper |
| Issue: | Volume: FDTD Methods and Applications Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 235 KB |
| Title: | Numerical Analysis of the Impact of Dynamic RF Spectrum Assignments on Resonating Cavities Using Standardized Data Comparison Techniques |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Antenna Design and Applications Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 167 KB |
| Title: | Numerical Analysis of a Printed E-Field RF Probe-Array Used for Rapid SAR Assessment |
| File Type: | Conference Paper |
| Issue: | Volume: Computational RF and Thermal Dosimetry Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 498 KB |
| Title: | Numerical Analysis and Preliminary Experimental Validation of a Heteropolar Electrodynamic Bearing |
| Abstract: | In this paper we describe the numerical simulations of a Heteropolar Electrodynamic Bearing and compare them with some experimental data taken on a prototype in quasi-static state. The device is composed of a cylindrical permanent magnet rotor and six coils fixed onto the stator. The system has been simulated by means of a dedicated numerical code (“EN4EM” - Electric Network for Electromagnetics), previously developed for research purposes. The software is based on a 3D integral formulation and it is able to numerically simulate coupled multi-degree of freedom electro/mechanical problems. The comparison between computed and measured data are fully satisfactory. |
| Author(s): | V. Kluyskens, B. Dehez, C. Dumont, A. Musolino, R. Rizzo |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 4 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2237 KB |
| Title: | Novel Multi-frequency Vehicle Antenna |
| File Type: | Conference Paper |
| Issue: | Volume: S04 Printed, Flexible and Reconfigurable Antenna Implementations Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 528 KB |
| Title: | Nonlinear Analysis of Rotor-AMB System with Current Saturation Effect |
| Abstract: | The analysis on nonlinear dynamics of a rotor-AMB system is conducted in this paper. The nonlinearity of electromagnetic force and current saturation effect are taken into account. The nonlinear model of the rotor-AMB system is built and the nonlinear dynamic behaviors of the system in both resonance region and non-resonance region are investigated through numerical integration method. This paper shows that the rotor-AMB system can exhibit some complicated nonlinear dynamic behaviors, such as soft spring characteristic of the amplitude-frequency response curve, the jump phenomenon, and pitchfork bifurcation. And the effects of exciting force and current saturation on these nonlinear dynamic behaviors of the system are discussed. |
| Author(s): | X. Zhang, T. Fan, Z. Sun, L. Zhao, X. Yan, J. Zhao, Z. Shi |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 4 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1515 KB |
| Title: | Nonlinear Analysis and Performance Improvement of Amplifying Aperture Coupled Reflectarray Antenna |
| Abstract: | Amplifying reflectarray antenna can be used to increase the overall gain of the antenna in large distance communication systems. However, amplifying reflectarray antenna may become nonlinear in some incident powers which may lead to performance degradation. In this paper nonlinear behavior of an amplifying reflectarray antenna is studied and a new method is proposed to improve the performance of the antenna. Nonlinear analysis of the active unit cell is performed using harmonic balance method considering nonlinear model of the amplifier. Then, the effect of nonlinear element in radiation pattern of the antenna is studied. Aperture coupled patch structure is used to analyze amplifying unit cell. Finally, an amplifying reflectarray antenna considering nonlinear behavior of the active elements is designed and the proposed balanced amplifier structure is used to improve performance of the amplifying antenna. |
| Author(s): | I. Aryanian, A. Abdipour, G. Moradi |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 10 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1502 KB |
| Title: | Non-uniform Feeding Network for a Dual Circularly Polarized 16×16 Ku-Band Antenna Array for On-Move Satellite Communication |
| Abstract: | This paper presents analysis and design of a dual circularly polarized 16×16 Ku band antenna array with emphasis on its feeding network. The proposed antenna is designed for on-move satellite communication system where the radiation pattern and the side-lobe level should meet the ITU standards to avoid interference with other satellite systems. This requirement is obtained by using non-uniform feeding distribution network. In addition, dual circular polarization operation requires sequential feeding networks with appropriate phase shift sequences. The proposed antenna is divided into 16 sub-cells of 4×4 radiating elements. The elements inside the sub-cell are fed by uniform dual sequential feeding networks. These sub-cells are connected together via two non-uniform feeding networks on a single layer in the shape of two interlaced fork configurations. In addition, cascaded power dividers are used to achieve the required low power division ratios between some of the sub-cells according to the required feeding distribution. These modifications simplify the fabrication process of the proposed antenna structure and reduce the required layers while satisfying the required radiation parameters. |
| Author(s): | W. M. Hassan, K. M. Ibrahim, E. A. Abdallah, A. M. Attiya |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 2 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1790 KB |
| Title: | Non-constant speeds of light in vacuum |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 107 KB |
| Title: | Non-conformal Domain Decomposition Methods for Solving Large Multi-scale Electromagnetic Scattering Problems |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Numerical Techniques for Multiscale EM Wave Problems Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 774 KB |
| Title: | New Solution Strategies For Solving Large Scale 3D Electromagnetic Inversion Problems |
| File Type: | Conference Paper |
| Issue: | Volume: Efficient Numerical Solutions of Large Multi-dimensional Inverse Scattering Problems Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 488 KB |
| Title: | New Features in Feko/WinProp 2019 |
| File Type: | Conference Paper |
| Issue: | Volume: S03 EM Modeling using Feko/WinProp Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 344 KB |
| Title: | New Features in Feko and WinProp 2019 |
| Abstract: | This paper describes some of the latest features in the commercial electromagnetic software Feko (including WinProp). These include the modeling of non-ideal cable shield connections, the parallel direct adaptive cross approximation (ACA) solver, edge and wedge diffraction for the ray launching geometrical optics (RL-GO) solver, and several new features related to automotive radar. |
| Author(s): | M. Schoeman, R. Marchand, J. van Tonder, U. Jakobus, A. Aguilar, K. Longtin, M. Vogel, T. Alwajeeh |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1102 KB |
| Title: | New Features in Altair Feko 2021 |
| File Type: | Conference Paper |
| Issue: | Volume: S08 EM Modeling using FEKO - I Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 556 KB |
| Title: | New Approximate Expressions for Evaluating the Fields of a Vertical Magnetic Dipole in a Dissipative Half Space |
| Abstract: | In this paper, a set of new asymptotic approximate expressions for evaluating the electromagnetic (EM) fields generated by a vertical magnetic dipole placed in a dissipative half space is proposed. The lateral wave that guarantees the continuity of the EM fields at the interface is discussed in detail. Using the spectral method, the integral expressions of the field components are obtained. The dominant part is extracted from the lateral wave for large radial distance so that all field components in this situation can be approximately expressed with explicit expressions, which makes the method efficient. Besides, the proposed method has no restriction condition on the parameter choices of different half spaces, so it can be applied in more general situations. Some calculation results and comparisons are given to validate the effectiveness of this extraction method. |
| Author(s): | H. Deng, G. Xiao, S. Huang |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 11 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1861 KB |
| Title: | Neural Network Approaches To The Processing of Experimental Electro-Myographic Data from Non-Invasive Sensors |
| Abstract: | Learning theories and algorithms for both supervised and unsupervised Neural Networks (NNs) have already been accepted as relevant tools to cope with difficult problems based on the processing of experimental electromagnetic data. These kinds of problems are typically formulated as inverse problems. In this paper, in particular, the electrical signals under investigations derive from experimental electromyogram interference patterns measured on human subjects by means of non-invasive sensors (surface ElectroMyoGraphic, sEMG, data). The monitoring and the analysis of dynamic sEMG data reveals important information on muscles activity and can be used to clinicians for both preventing dramatic illness evolution and improving athletes performance. The paper proposes the use of Independent Component Analysis (ICA), an unsupervised learning technique, in order to process raw sEMG data by reducing the typical “cross-talk” effect on the electric interference pattern measured by the surface sensors. The ICA is implemented by means of a multi-layer NN scheme. Since the IC extraction is based on the assumption of stationarity of the involved sEMG recording, which is often inappropriate in the case of biomedical data, we also propose a technique for dealing with non-stationary recordings. The basic tool is the wavelet (time-frequency) decomposition, that allows us to detect and analyse time-varying signals. An auto-associative NN that exploits wavelet coefficients as an input vector is also used as simple detector of non-stationarity based on a measure of reconstruction error. The proposed approach not only yields encouraging results to the problem at hand, but suggests a general approach to solve similar relevant problems in some other experimental applications of electromagnetics. |
| Author(s): | Francesco Carlo Morabito, Maurizio Campolo, Francesco Carlo Morabito, Maurizio Campolo |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 2 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 908 KB |
| Title: | Near-Field Far-Field Transformations for Automobile Antenna Measurements |
| File Type: | Conference Paper |
| Issue: | Volume: S14 Numerical Methods for Analysis, Design and Measurement of Antennas I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 353 KB |
| Title: | NEAR FIELDS OF A LOGAEPERIODIC DIPOLE ANTENNA: NEC MODELLING AND COMPARISON WITH MEASUREMENTS |
| Abstract: | Experiences of modelling a log-periodic antenna (tapered transmission line type) using NEC are reported. The antenna is required as a component of a near-field EMC test range, and hence computation of the near fields was the primary objective although some discussion of impedance is presented. Measurements of the near field of the real antenna were undertaken on a planar measurement range having the ability to scan planes at varying distances from the antenna. The measurements show good agreement with the predictions of NEC. [Vol. 2, No. 2, pp. 122-130 (1987)] |
| Author(s): | K. T. Wong, P. S. Excell, K. T. Wong, P. S. Excell |
| File Type: | Journal Paper |
| Issue: | Volume: 2 Number: 2 Year: 1987 |
| Download Link: | Click here to download PDF File Size: 773 KB |
| Title: | A RECURSIVE TECHNIQUE TO AVOID ARITHMETIC OVERFLOW AND UNDERFLOW WHEN COMPUTING SLOWLY CONVERGENT EIGENFUNCTION TYPE EXPANSION. |
| Abstract: | Eigenfunction expansions for fields scattered by large structures are generally very slowly convergent. The summation often consists of two factors where one factor approaches zero and the other factor grows in magnitude without bound as the summation index increases. Each term of the expansion is bounded; however, due to the extreme magnitude of the individual factors, computational overflow and underflow errors can limit the number of terms that can be computed in the summation thereby forcing the summation to be terminated before it has converged. In this paper an exact technique that circumvents these problems is presented. An auxiliary function is introduced which is proportional to the original factor with its asymptotic behavior factored out. When these auxiliary functions are introduced into the summation, we are left with the task of numerically summing products of well behaved factors. A recursion relationship is developed for computing this auxiliary function. [Vol. 7, No. 1, pp. 67-77 (1992)] |
| Author(s): | Gary A. Somers, Benedlkt A. Munk, Gary A. Somers, Benedlkt A. Munk |
| File Type: | Journal Paper |
| Issue: | Volume: 7 Number: 1 Year: 1992 |
| Download Link: | Click here to download PDF File Size: 508 KB |
| Title: | Three-Dimensional Geometrical Optics Code for Indoor Propagation |
| Abstract: | This paper presents program GO_3D for computing the fields of a transmitter in an indoor environment using geometrical optics. The program uses an “image tree” data structure to construct the images needed to compute all the rays carrying fields above a preset “threshold” value, no matter how many reflections are needed. The paper briefly describes the input file required to define wall construction, the floor plan, the transmitter, and the receiver locations. A case study consisting of a long corridor with a small room on one side is used to demonstrate the features of the GO_3D program. |
| Author(s): | C.W. Trueman, C.W. Trueman |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 2 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 733 KB |
| Title: | Simulations of a Shaped Dielectric Lens Antenna by FEKO |
| Abstract: | In the Intelligent Transportation System (ITS), millimeter waves are used and antennas are requested to have beam scanning ability. In the millimeter wave operation, a dielectric lens antenna is one of the prominent candidates. Authors designed a shaped dielectric lens antenna based on the Abbe’s sine condition. Wide angle beam scanning characteristics were ensured through the ray tracing calculations and radiation pattern measurement. Recently, owing to the enhancement of electromagnetic simulator abilities, simulations of a dielectric lens antenna become possible. By employing an electromagnetic simulation, it is expected that detailed electrical performances of both the feed horn and the dielectric lens will be made clear. In this paper, electromagnetic simulations of a shaped dielectric lens antenna by FEKO suit 5.3 are conducted. First, the corrugate horn used for the feed horn is electromagnetically simulated. Excellent simulated radiation patterns coinciding with the measured results are achieved. Next, the feed horn radiation patterns are combined with the dielectric lens simulations. And simulation results of beam scanning characteristics are obtained. When comparing the simulated scanned beam shapes with the measured results, very good agreements are obtained. So, accuracies of simulations are ensured. Moreover, unexpected sidelobe increases in the specific wide angle region that were pointed out previously are studied. Simulated and measured results can confirm the sidelobe increases. As an additional study, electrical field distributions in the dielectric lens are simulated. Then, multiple reflections between lens surfaces are visually made clear. The reason of sidelobe increases can be clearly understood. As a result, it is confirmed that the FEKO simulator can rigorously simulate electromagnetic characteristics of a shaped dielectric lens antenna. |
| Author(s): | Y. Tajima, Y. Yamada |
| File Type: | Journal Paper |
| Issue: | Volume: 24 Number: 4 Year: 2009 |
| Download Link: | Click here to download PDF File Size: 1594 KB |
| Title: | Simple and Efficient BZT-Higher-Order PML Formulations for the Metal Plate Buried in Three-Dimensional Dispersive Soil Space Problems |
| Abstract: | Efficient and unsplit-field higher-order PML formulations using the stretched coordinate perfectly matched layer (SC-PML) formulations and the bilinear Z-Transform (BZT) method are presented for truncating the finite-difference time-domain (FDTD) lattices. This method is completely independent of the material properties of the FDTD computational domain and hence can be applied to the modeling of arbitrary media without any modification because of the D-B constitutive relations used. The higher-order PML has the advantages of both the conventional PML and the complex frequency-shifted PML (CFS-PML) in terms of absorbing performances. Two 3D FDTD simulations of the metal plate buried in dispersive soil space FDTD domains have been carried out to validate these formulations. It is shown that the proposed PML formulations with the higher-order scheme are efficient in terms of attenuating both the low- frequency propagating waves and evanescent waves and reducing late-time reflections. |
| Author(s): | N. Feng, Q. H. Liu, C. Zhu |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 10 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 247 KB |
| Title: | Radiowave Propagation prediction in the Presence of Multiple Knife Edges using 3D Parabolic Equation Method |
| File Type: | Conference Paper |
| Issue: | Volume: 9-P-2 Poster Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 220 KB |
| Title: | Phase-Matching the Hybrid M24/S22 FDTD Algorithm |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Computational Techniques in Electromagnetics - 2 Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 3500 KB |
| Title: | Optimization-Based Matching Layer Design for Broadband Dielectric Lens Antennas |
| Abstract: | Dielectric lens antennas fabricated with a dense dielectric material, allow good power transfer efficiency through the lens and enable fabrication of low-cost and compact-size lens antennas. On the contrary, using dense dielectric material causes strong multiple internal reflection behavior inside the lens antenna. These multiple reflections deteriorate not only return loss but also the radiation characteristics. However, the undesirable effects of strong internal reflections can be reduced considerably using one or more dielectric Matching Layers (MLs) coated at the top of the antenna. In this paper, a novel optimizationbased ML design procedure for dielectric lens antennas is proposed. In order to demonstrate effectiveness of the method, the optimization procedure is applied to two different dielectric lens antennas; a narrow band lens antenna and an Ultra-Wideband (UWB) lens antenna. The simulation results verify that MLs designed by the proposed optimization procedure prevent strong internal reflections successfully for both narrowband and UWB applications. |
| Author(s): | F. Tokan |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1251 KB |
| Title: | Numerical solution of time-dependent Maxwell\'s equations in spherical coordinates |
| File Type: | Conference Paper |
| Issue: | Volume: FDTD Methods and Applications Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 84 KB |
| Title: | Modeling and Analysis of Anechoic Chamber Using CEM Tools |
| Abstract: | Advances in computational resources facilitate anechoic chamber modeling and analysis at VHF/UHF frequencies using full-wave solvers available in commercial software such as FEKO. The measurement community has a substantial and increasing interest in utilizing computational electromagnetic (CEM) tools to minimize the financial and real estate resources required to design and construct a custom anechoic chamber without sacrificing performance. A full-wave simulation analysis such as the finite element method (FEM) provides a more accurate solution than the approximations inherent to asymptotic ray-tracing techniques such as physical optics (PO), which have traditionally been exploited to overcome computational resource limitations. An anechoic chamber is simulated with a rectangular down-range cross-section (in contrast with the traditional square cross-section) to utilize the software’s capability to assess polarization performance. The absorber layout within the anechoic chamber can be optimized using FEKO for minimal reflections and an acceptable axial ratio in the quiet zone. Numerical results of quiet zone disturbances and axial ratios are included for both low- and medium-gain source antennas over a broad frequency range. |
| Author(s): | D. Campbell, G. Gampala, C. J. Reddy, M. Winebrand, J. Aubin |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 9 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 889 KB |
| Title: | Linearization of S-Parameter Cascading for Analysis of Multiple Reflections |
| Abstract: | This paper develops a method to derive intuitive understanding of the root causes of reflective interference created by the many impedance discontinuities between the packages, PCBs and connectors. Scattering parameters are cascaded to describe the system response and linearized to analyze the multiple reflections. An upper error bound of the linearization is derived and is validated with Monte Carlo studies. |
| Author(s): | R. J. Allred, C. M. Furse |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 12 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 2010 KB |
| Title: | Light Wave Propagation Model for Indoor Visible Light Communication Systems Employing Small LED Sources |
| Abstract: | The aim of the present work is to build a robust and computationally efficient model for the light wave propagation in indoor visible light communication (VLC) systems. It is assumed that a small (point) LED source is used inside a room of relatively small dimensions (room area ≤ 5m × 5m). The light wave is treated as an electromagnetic wave suffering multiple reflections on the walls of the room. The Geometrical Theory of Diffraction (GTD) is applied for evaluation of the light wave reflection on the rough walls of the room. Also, the present work is concerned with developing a new computational method for the assessment of intersymbol interference (ISI) encountered in such indoor VLC systems. The signal strength, the power of ISI, and hence, the signal-to-ISI ratio (SISIR) are evaluated over the horizontal plane of the mobile units (at a height of about 1m above the room floor). The effects of the room dimensions and some structural parameters such as the reflectance of the side walls on the SISIR are numerically investigated. |
| Author(s): | M. M. A. Elsaaty, A. Zaghloul, K. F. A. Hussein |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2441 KB |
| Title: | Hybrid Numerical–Asymptotic Modeling of Electrically Large EM Structures |
| File Type: | Conference Paper |
| Issue: | Volume: Hybrid Numerical Techniques in EM for Modeling Electrically Large Structures Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 336 KB |
| Title: | Ground Penetrating Radar Radargram Filter using Singularity Expansion Method |
| Abstract: | In this paper, the singularity expansion method (SEM) is used to improve the signal-to-clutter ratio of radargrams obtained with a ground penetration radar (GPR). SEM allows to select the poles of the GPR signals corresponding to unwanted signals, clutter, and also reflections of specific buried objects. A highly reflective metallic material was used to assess the use of SEM as a tool to eliminate unwanted reflections and signals produced by a GPR. Selected clutter poles are eliminated from each frame of the SAR image in order to keep only desired poles for analysis. Finally, the reconstructed radargram obtained applying SEM is compared with the image obtained using a well-known processing technique. Results show that the proposed technique can be used to straightforwardly remove undesired signals measured with GPRs. |
| Author(s): | E. F. Ruiz, D. Chaparro-Arce, J. J. Pantoja, F. Vega, C. Kasmiv, F. Al Yafei |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1169 KB |
| Title: | Frequency Selective Surface Network for In-Phase Ground Plane Reflections in Tightly Coupled Dipole Arrays |
| File Type: | Conference Paper |
| Issue: | Volume: S16 Metamaterial, Devices, and Antenna Applications Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 2851 KB |
| Title: | First and Second Order Mur Type ABCs for DNG Media |
| Abstract: | Reflections from boundaries of the FDTD computational domain lead to inaccurate, even unstable codes when dealing with problems involving double negative (DNG) materials. Here, an efficient and simple algorithm is presented for terminating FDTD in DNG medium which is based on first and second order Mur’s absorbing boundary conditions (ABC). FDTD update equations for Mur’s ABC formulations are obtained from frequency domain one-way wave equations using piecewise linear recursive convolution (PLRC) method. Numerical examples are given both for 1D and 2D scenarios to demonstrate the validity and stability of the proposed Mur formulations, and its advantages over uniaxial perfectly matched layer (UPML) in reducing computational time and memory requirements. |
| Author(s): | A. Pekmezci, E. Topuz, L. Sevgi |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 6 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1769 KB |
| Title: | FEMC Performance of Pyramidal Microwave Absorber using Sugarcane Baggasse and Rubber Tire Dust at 1 GHz to 18 GHz Frequencies |
| Abstract: | The solid, geometrically tapered microwave absorbers are preferred due to their better performance. The goal of this study is to design absorbers that can reduce the electromagnetic reflections to less than -10 dB. Two waste materials of sugarcane bagasse and rubber tire dust in the powder form were used to fabricate independent samples in the pyramidal form. This paper presents the complex permittivity measurements of sugarcane bagasse and rubber tire dust materials. These two materials are found to be potential absorbing materials in microwave frequency to allow absorption of microwave EMI energy. The materials were combined and fabricated in the composite structure. A measurement system using open- ended coaxial probe method was used for characterizing the dielectric properties of the materials in the range of 1 to 18 GHz microwave frequencies. The dielectric property was used to compare the propagation constants of the material. Comparison of the results proved that these two materials have industrial potential to be fabricated as solid absorbers. |
| Author(s): | L. Zahid, M. Jusoh, R.-B. Ahmad, T. Sabapathy, M. F. Malek, M. R. Kamarudin, M. N. Yasin, M. N. Osman |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2231 KB |
| Title: | Extended Radar Return from a Rocket Engine: A Thermal Model |
| File Type: | Conference Paper |
| Issue: | Volume: Topics in Radar Scattering Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 129 KB |
| Title: | Enhanced Functionality for Hardware-Based FDTD Accelerators |
| Abstract: | In this paper we present several architectural enhancements to our previously published hardware-based FDTD acceleration platform. This includes the addition of several new sources, including H-polarized point sources, voltage and current sources, Gaussian beams, and user-defined sources, such as waveguide mode profiles. We also discuss the recent support for extending objects into the absorbing boundary, which minimizes non-physical back reflections. With the addition of these features, the FDTD acceleration hardware has become a more robust and powerful tool, enabling the rapid simulation of a wider breadth of applications, including antennas, waveguides, and optics. |
| Author(s): | Petersen F. Curt, James P. Durbano, Michael R. Bodnar, Shouyuan Shi, Mark S. Mirotznik, Petersen F. Curt, James P. Durbano, Michael R. Bodnar, Shouyuan Shi, Mark S. Mirotznik |
| File Type: | Journal Paper |
| Issue: | Volume: 22 Number: 1 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 1807 KB |
| Title: | Enhanced Functionality for Hardware-Based FDTD Accelerators |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Computational Techniques in Electromagnetics - 2 Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 204 KB |
| Title: | Eliminating Interface Reflections in Hybrid Low-Dispersion FDTD Algorithms |
| Abstract: | The numerical phase mismatch across FDTD lattice layers with different sets of update equations has been investigated. A predictive equation of numerical reflections across high-order/low-order layers has been derived. Based on this equation the standard Yee (S22) update equations have been modified to allow their implementation around PEC boundaries and other special situations in an otherwise global high-order implementation, while keeping spurious reflections at the hybrid interface to a practical minimum and independent of the traversing wave direction. S22 Phase matching has been developed and verified in both S24 and M24 high-order hybrid algorithms. |
| Author(s): | Mohammed F. Hadi, Rabie K. Dib, Mohammed F. Hadi, Rabie K. Dib |
| File Type: | Journal Paper |
| Issue: | Volume: 22 Number: 3 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 2458 KB |
| Title: | Efficient Z-Transform Implementation of the D-B CFS-PML for Truncating Multi-Term Dispersive FDTD Domains |
| Abstract: | Efficient Z-transform implementation of the Complex Frequency-Shifted Perfectly Matched Layer (CFS-PML) using the D-B formulations are proposed to truncate open region multi-term dispersive Finite-Difference Time-Domain (FDTD) lattices. These formulations are independent of material properties of the FDTD domains and hence can be used for modeling general media because of the D-B constitutive relations. A Three-Dimensional (3-D) simulation of the two-term Lorentz dispersive FDTD domain has been carried out to demonstrate the validity of the proposed formulations. Furthermore, in order to show the validity of the proposed algorithm, the second 3D inhomogeneous problem has also been used for validating the proposed formulations. It is clearly shown that the new formulations with the CFS-PML scheme are efficient in attenuating evanescent waves and reducing late-time reflections. |
| Author(s): | N. Feng, Y. Yue, C. Zhu, Q. H. Liu, L. Wan |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 3 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 255 KB |
| Title: | Efficient Suppression of Artificial Reflections in the TF/SF Scheme for the Nonstandard FDTD Method |
| File Type: | Conference Paper |
| Issue: | Volume: S63 Differential Equation Methods I Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 1441 KB |
| Title: | Effects of Internal Reflections on The Performance of Lens-Integrated mmW and THz Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: S14 Numerical Methods for Analysis, Design and Measurement of Antennas I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 757 KB |
| Title: | Effective CFS-PML Formulations Based on 2-D TE phi BOR-FDTD for the Drude Model |
| Abstract: | Effective formulations of the complex frequency-shifted perfectly matched layer (CFS-PML) based on the two-dimensional (2-D) TE phi body of revolution finite-difference time-domain (BOR-FDTD), named as the BOR-CFS-PML, are proposed to truncate the Drude media. The auxiliary differential equation (ADE) method and the trapezoidal recursive convolution (TRC) method are applied to the implementation of the BOR-CFS-PML. The proposed formulations have good performance in attenuating low-frequency evanescent waves and reducing late-time reflections. A numerical test is provided to validate the effectiveness of the proposed algorithm. |
| Author(s): | J. Li, W. Jiao |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 4 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1578 KB |
| Title: | Computational Design and Analysis of Radomes |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Simulation of Electrically Large Problems Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 372 KB |
| Title: | Closed-Form Optimization of CPML Absorbing Boundary Conditions |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in FDTD Method and Applications Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 111 KB |
| Title: | Analytical Estimation of Radar Cross Section of Arbitrary Compact Dipole Array |
| Abstract: | This paper presents the scattering estimation and analysis of an arbitrary phased array with parallel, centre-fed dipole elements, in the presence of mutual coupling. The total Radar Cross Section (RCS) of the uniform dipole array is computed by considering the signal reflections within the array system. The results are shown for two types of feed networks, viz. series feed and parallel feed. The scattering due to higher order reflections and edge effects are neglected. The analytical formulae presented for array RCS emphasize the dependence of scattered field on the design parameters, like dipole length, interelement spacing, geometrical and electrical properties of phase shifters, couplers and terminal impedances. The results indicate that the mutual coupling effect on the overall RCS pattern is identical for both equal and unequal length dipole arrays. This paper identifies the design parameters that can be optimized towards the RCS control of phased array. These parameters include dipolelength, geometric configuration and terminal impedance. |
| Author(s): | H. L. Sneha, H. Singh, R. M. Jha |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 9 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1191 KB |
| Title: | An Approximate Boundary Condition for Piezoelectric Crystals using FDTD |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced FVTD/DG/FDTD Techniques Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 419 KB |
| Title: | A PML for Electroacoustic Waves in Piezoelectric Materials Using FDTD |
| Abstract: | A perfectly matched layer (PML) is introduced for elastodynamic waves in piezoelectric materials. A matching condition is derived for the PML equations to reduce spurious reflections from the boundary. The finite difference time domain (FDTD) is used to model the propagation of the wave in the piezoelectric material. The results show good performance of the proposed PML boundary. |
| Author(s): | A. O. Montazeri, M. H. Bakr, Y. M. Haddara |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 6 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 4441 KB |
| Title: | A Pathloss Model Based on Ray Tracing for Indoor MIMO Channel |
| File Type: | Conference Paper |
| Issue: | Volume: CEM Activities in China Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 375 KB |
| Title: | A Microstrip Excitation Technique in FVTD and its Application to Slot-Fed Dielectric Resonator Antennas |
| File Type: | Conference Paper |
| Issue: | Volume: Dielectric Resonator Antennas Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 642 KB |
| Title: | A Fourier Split-Step Based Wide-Angle Three-Dimensional Vector Parabolic Wave Equation Algorithm Predicting the Field Strength Over Flat and Irregular Forest Environments |
| Abstract: | This paper provides the analysis of radio wave propagation prediction over flat and irregular forest environments. A three-dimensional vector parabolic wave equation (3DPE) method is used to calculate the field strength due to the forest on a lossy ground. Forest terrains are equivalent to a series of absorbing blocks arranged along the direction of propagation. Under the assumption of forwarding propagation, a 3DPE is derived and the Fourier split-step based PE (SSPE) method is adopted to march the potentials from one aperture plane to the next. A Tukey window function is used to attenuate the fields smoothly at the upper boundary without reflections. Finally, the simulation results are compared with the analytical methods presented in the literature. The simulation results have shown the validity of the proposed algorithm. |
| Author(s): | H. F. Rasool, X.-M. Pan, X.-Q. Sheng |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 6 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1434 KB |
| Title: | SUB-GRIDDING FDTD SCHEMES |
| Abstract: | Local meshing or sub-gridding has been advocated by a number of authors as a way of increasing the spatial resolution of the finite difference time domain method (FDTD). In this paper we show how to use supraconvergence to analyze the error in a simple sub-gridding strategy in two dimensions. We also analyze the spurious reflection that occurs at an interface between two grids for the standard FDTD scheme, for simple subgridding method and for another subgridding scheme employing linear interpolation. The overall order of convergence of the reflection coefficients is the same for all the methods, but the linear scheme has a lower amplitude spurious transmitted mode compared to the simple subgridding scheme. |
| Author(s): | Peter Monk, Peter Monk |
| File Type: | Journal Paper |
| Issue: | Volume: 11 Number: 1 Year: 1996 |
| Download Link: | Click here to download PDF File Size: 700 KB |
| Title: | A LOW-FREQUENCY FORMULATION OF THE METHOD OF MOMENTS VIA SURFACE CHARGES |
| Abstract: | In this paper a formulation of the method of moments for the analysis of low frequency problems is presented. In the considered frequency range, the integral solution of Maxwell equations in terms of magnetic vector potential and electric scalar potential respectively function of currents and charges is obtained imposing the Coulomb gauge. By combining Gauss law and current continuity at the boundaries among regions with different conductivity a first set of equations is obtained. Writing Ohm's law inside the conductive regions another integral equation set that allows the determination of the conduction current and surface charges unknowns is obtained. The method of moments is then applied to this system of equations. The use of pulse functions as subsectional bases allows a quick matrix set up especially when regular volume shapes are selected. Calculated results are compared with results obtained with other methods relating to benchmark problems. [Vol. 10, No. 3 (1995), Special Issue on Advances in the Application of Method of Moments to Electromagnetic Radiation and Scattering Problems, pp 53-57] |
| Author(s): | Nunzio Esposito, Antonino Musolino, Marco Raugi, Nunzio Esposito, Antonino Musolino, Marco Raugi |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 3 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 332 KB |
| Title: | A STUDY OF A RECENT, MOMENT-METHOD ALGORITHM THAT IS ACCURATE TO VERY LOW FREQUENCIES |
| Abstract: | We give an alternative description of a recently published moment-method algorithm, which uses divergence-free and rotation-free basis functions to maintain accuracy down to very low frequencies. The basic algorithm is restricted to simply-connected and non-self-intersecting surfaces. But this restriction has little practical impact--we show how multiply-connected surfaces, self-intersecting surfaces, and one-sided surfaces can easily be converted to the required topology without changing the solution. We examine a claim that the impedance matrix is diagonally dominant, which implies a guaranteed-to-converge Jacobi type of iterative solution of the matrix equation. Finally, we show how to control catastrophic-cancellation errors that occasionally appear in the voltage vector. [Vol. 10, No. 3 (1995), Special Issue on Advances in the Application of Method of Moments to Electromagnetic Radiation and Scattering Problems, pp 58-68] |
| Author(s): | M. Burton, S. Kashyap, M. Burton, S. Kashyap |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 3 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 795 KB |
| Title: | ELECTROMAGNETIC SCATTERING FROM TWO DIMENSIONAL ANISOTROPIC IMPEDANCE OBJECTS UNDER OBLIQUE PLANE WAVE INCIDENCE |
| Abstract: | The surface integral equations of a two dimensional (2D) anisotropic impedance object is formulated to obtain the electromagnetic scattered fields due to oblique plane wave incidence. The surface impedance is anisotropic with arbitrary principle directions. The moment method with pulse basis functions and point matching is used to reduce the surface integral equations to a matrix equation. Four different formulations are generated for the problem. The surface current distributions and the scattered farfields are verified against the analytical series solutions of circular impedance cylinders. Very good agreement between the numerical and the analytical solutions is obtained. A rectangular cylinder made of four soft surfaces is analyzed for oblique incidence to verify that the results behave as expected. The computer code is also verified by comparing the solutions of the different formulations against each other. [Vol. 10, No. 3 (1995), Special Issue on Advances in the Application of Method of Moments to Electromagnetic Radiation and Scattering Problems, pp 81-92] |
| Author(s): | Ahmed A. Kishk, Per-Simon Kildal, Ahmed A. Kishk, Per-Simon Kildal |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 3 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 1148 KB |
| Title: | A TECHNIQUE FOR AVOIDING THE EFIE "INTERIOR RESONANCE" PROBLEM APPLIED TO AN MM SOLUTION OF ELECTROMAGNETIC RADIATION FROM BODIES OF REVOLUTION |
| Abstract: | Various surface integral equation formulations, including the electric (EFIE) and magnetic (MFIE) field integral equations, suffer from what is commonly known as the "interior resonance" problem. There are a number of remedies to this problem of which many involve modifying the integral equation formulation and result in increased computational effort and computer storage re- quirements. In an attempt to avoid this the application of a remedy, proposed in the literature, which requires no modification to the formulation has been investigated. This involves the detection of interior resonance frequencies and correction of the current by removing the mode responsible for the 'interior resonance". In the literature, the success of the remedy has been demonstrated for two-dimensional scattering problems involving PEC cylinders. In this work it is demonstrated that, while the correction of the MM (moment method) solution is successful when an "interior resonance" has been detected, the detection of the interior resonance frequencies can be extremely difficult in an MM solution of radiation from composite bodies of revolution. In fact, a foolproof computational algorithm for detecting interior resonance frequencies for this class of problems is yet to be developed. [Vol. 10, No. 3 (1995), Special Issue on Advances in the Application of Method of Moments to Electromagnetic Radiation and Scattering Problems, pp 116-128 |
| Author(s): | Pierre Steyn, David B. Davidson, Pierre Steyn, David B. Davidson |
| File Type: | Journal Paper |
| Issue: | Volume: 10 Number: 3 Year: 1995 |
| Download Link: | Click here to download PDF File Size: 1107 KB |
| Title: | TWO WIRE RHOMBIC ILLUMINATOR PERFORMANCE AS PREDICTED BY THEORETICAL AND NUMERICAL MODELS |
| Abstract: | The two wire rhombic illuminator (RI) is a rhombic wire antenna located over a ground plane which is used to generate near uniform electromagnetic fields over a specified working volume located below the antenna. The RI can be modeled as a simple two-wire transmission line at low frequencies but the transmission line model becomes inadequate at higher frequencies due to the enhanced radiation properties of the antenna. The performance of the RI including radiation effects is evaluated numerically using the Numerical Electromagnetics Code (NEC-2) and compared to that of the transmission line model. The antenna in the presence of a perfectly conducting ground plane is analyzed at frequencies ranging from 1 MHz to 500 MHz. Various segmentation schemes are utilized in order to accurately predict the performance of the RI at frequencies where the dimensions of the structure are very large in terms of wavelength. [Vol. 9, No. 1 (1994), pp 88- 101] |
| Author(s): | J. Patrick Donohoe, Saad N. Tabet, C.D. Taylor, J. Patrick Donohoe, Saad N. Tabet, C.D. Taylor |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 1 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 782 KB |
| Title: | COMPUTATION OF STATIC AND QUASISTATIC ELECTROMAGNETIC FIELD USING ASYMPTOTIC BOUNDARY CONDITIONS |
| Abstract: | This paper presents the computation of static and quasistatic electromagnetic fields using asymptotic boundary conditions (ABC). Asymptotic boundary conditions for eddy current problems due to external field excitations are derived. For electrostatic fields, ABC-s are used in conjunction with Laplace's equation while for quasistatic magnetic fields, ABC-s are employed in conjunction with the integrodifferential finit element method. The effect of outer boundary locations on the accuracy of the simulation results is examined. This study shows that in these cases, ABC-s can improve the computation accuracy compared to the usual truncation of outer boundaries. [Vol. 9, No. 2 (1994), Special Issue on The Numerical Computation of Low Frequency Electromagnetic Fields, pp 37-42] |
| Author(s): | Qiushi Chen, Adalbert Konrad, Paul P. Biringer, Qiushi Chen, Adalbert Konrad, Paul P. Biringer |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 2 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 485 KB |
| Title: | AN IMPROVED NETWORK MODEL FOR EDDY CURRENT PROBLEMS |
| Abstract: | This paper describes improvements in modelling Maxwell's equations in two dimensions using the electrical network analogue. Two network models are described with major emphasis placed on diffusion dominated problems. The first one is the combined fine-coarse mesh approach which was initially developed for the method of transmission-line modelling (TLM). The combined fine-coarse mesh technique is then modified by introducing controlled sources at the interfacing between the fine and the coarse mesh. Several numerical experiments, including one with both a conducting region and free space, are used to study the two models. They are also compared with the standard network analogue using a regular meshing. Numerical results are compared with analytical or published data. In all cases, SPICE (or PSPICE) has been used to solve the resulting network analogues. [Vol. 9, No. 2 (1994), Special Issue on The Numerical Computation of Low Frequency Electromagnetic Fields, pp 74-82] |
| Author(s): | Chi-Chung Wong, Chi-Chung Wong |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 2 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 481 KB |
| Title: | APPLICATION OF BEM FOR CALCULATING THE PARAMETERS OF CABLES AND TRANSMISSION LINES |
| Abstract: | The capacitances of three phases cable and the characteristic impedance of coaxal transmission line with complicated shape of the cross sections are evaluated by using boundary element method. The calculated results obtained by the proposed method are coincident well with the results given by the literatures [2-9]. [Vol. 9, No. 2 (1994), Special Issue on The Numerical Computation of Low Frequency Electromagnetic Fields, pp 111-113] |
| Author(s): | Zhou Pei-bai, Zhong Hon-yu, Zhou Pei-bai, Zhong Hon-yu |
| File Type: | Journal Paper |
| Issue: | Volume: 9 Number: 2 Year: 1994 |
| Download Link: | Click here to download PDF File Size: 243 KB |
| Title: | CAL - ANTENNAS COMPUTER-AIDED LEARNING OF ANTENNAS |
| Abstract: | CAL-ANTENNAS is a tool containing graphics ( 2D and 3D) and sounds coded in the Turbo Pascal 5.5 language, for the implementation of educational software on antennas. From the Units files, a data base (frequency bands, antenna forms, antenna dimensions, formulae, characterising radiation) and a repertory of numericals methods (integration, graphs plotting, etc...) have been developped, complying with speed contraints. The necessary fundamental principles are contained in text files. Thus, this is one of the first structured software packages developed on the computer in the domain of antennas that treats the fundamental principles and the methodology of design. This version of CAL-ANTENNAS for the microcomputer based on the Intel 386 and 486 Microprocessors contains more than a hundred illustrations. [Vol. 8, No. 1, (1993), Special Issue on Computer Applications in Electromagnetics Education, pp 138-156] |
| Author(s): | Emmanuel TONYE, Olivier VIDEME BOSSOU, Emmanuel TONYE, Olivier VIDEME BOSSOU |
| File Type: | Journal Paper |
| Issue: | Volume: 8 Number: 1 Year: 1993 |
| Download Link: | Click here to download PDF File Size: 773 KB |
| Title: | ELECTRICAL IMPEDANCE TOMOGRAPHY IN THREE DIMENSIONS |
| Abstract: | An algorithm is developed for electrical impedance tomography (EIT) of three-dimensional volumes using multi-planar electrode arrays. This algorithm is based upon the method of least squares, and uses one step of Newton's method to estimate the conductivity distribution inside the volume using electrical measurements made on the boundary. An implementation of the algorithm for right cylindrical volumes is described. This computer code, called N3D, permits reconstructions with up to 2016 degrees of freedom. The code uses an initial guess consisting of uniform conductivity, allowing many of the computations to be done analytically. Although the code does not reconstruct the conductivity distribution accurately (unless it differs very little from a constant), it does yield useful images at reasonable computational cost. The algorithm is demonstrated using three-dimensional resistivity distributions reconstructed from experimental data. [Vol. 7, No. 2, pp. 128-147 (1992), Special Issue on Bioelectromagnetic Computations] |
| Author(s): | J. Goble, M. Cheney, D. Isaacson, J. Goble, M. Cheney, D. Isaacson |
| File Type: | Journal Paper |
| Issue: | Volume: 7 Number: 2 Year: 1992 |
| Download Link: | Click here to download PDF File Size: 2367 KB |
| Title: | NUMERICAL TECHNIQUES TO DETERMINE THE UTD BISTATIC CREEPING WAVE PATHS AND PARAMETERS FOR AN ELLIPSOID |
| Abstract: | In applying the Uniform Geometrical Theory of Diffraction (UTD) to evaluate the scattering patterns of a doubly curved surface, the determination of correct ray paths is one of the most important and difficult tasks. In this paper, an efficient numerical technique to obtain the complete ray path of the creeping wave for the bistatic scattering of an ellipsoid is discussed. Also, the numerical method to evaluate the energy spreading factor of the creeping wave and the caustic distance at the diffraction (launching) point are described. An ellipsoid is chosen because of its modeling capability to represent the fuselage of an aircraft and similar objects. The same numerical techniques for an ellipsoid can be extended to a general doubly curved surface as well. [Vol. 6, No. 1, pp. 140-158 (1991), Special Issue on Applicatlons of High Frequency Methods and Computer Techniques in Electromagnetics] |
| Author(s): | Jaehoon Choi, Ronald J. Marhefka, Jaehoon Choi, Ronald J. Marhefka |
| File Type: | Journal Paper |
| Issue: | Volume: 6 Number: 1 Year: 1991 |
| Download Link: | Click here to download PDF File Size: 932 KB |
| Title: | DESCRIPTION OF A RADAR CROSS SECTION PREDICTION CODE WITH APPLICATIONS TO INDUSTRIAL PROBLEMS |
| Abstract: | Following the recent advances in the fields of electromagnetic prediction theory and computer power, and a growing interest to low observables or stealth platforms [1], new software tools for the calculation of radar backscattering have been developed in several companies/institutions. While the basics of the algorithms used are the same, each code has been focused on different ranges of frequencies, kinds of platforms, and so on. This paper describes the prediction code developed at IDS, which is currently used in consultancy activities in the fields of design of new platforms with reduced/controlled RCS, as well as evaluation of the radar signature of existing systems. [Vol. 6, No. 1, pp. 159-174 (1991), Special Issue on Applications of High Frequency Methods and Computer Techniques in Electromagnetics] |
| Author(s): | Francesco Zacca, Giuliano Bettini, Riccardo Cioni, Francesco Zacca, Giuliano Bettini, Riccardo Cioni |
| File Type: | Journal Paper |
| Issue: | Volume: 6 Number: 1 Year: 1991 |
| Download Link: | Click here to download PDF File Size: 3549 KB |
| Title: | ANALYTIC RAY TRACING FOR THE STUDY OF HF MAGNETO-IONIC RADIO PROPAGATION IN THE IONOSPHERE |
| Abstract: | Ray tracing provides a quantitative tool for the study of HF radio wave propagation in the ionosphere, but its use is limited in many applications by the time required to numerically trace many separate rays. One approach to overcoming this problem is the use of ionospheric models that admit analytic solutions of the ray tracing equations. Such a model may be based on a vertical plasma frequency profile consisting of what are known as quasi-parabolic segments. Analytic tracing is much faster than numerical tracing (from 5 to 10 times), but more limited in the range of situations that can be considered. The main thrust of the paper is to present and test a technique, based on the use of an equivalent operating frequency, that allows the analytic results to be extended to take approximate account of the magneto-ionic effects associated with the earth's magnetic field. Errors in group path, phase path and ground range are generally less than 5 km, errors in absorption generally less than 5%. [Vol. 6, No. 1, pp. 192-210 (1991), Special Issue on Applications of High Frequency Methods and Computer Techniques in Elcctromagnetics] |
| Author(s): | J. A. Bennett, J. Chen, P. L. Dyson, J. A. Bennett, J. Chen, P. L. Dyson |
| File Type: | Journal Paper |
| Issue: | Volume: 6 Number: 1 Year: 1991 |
| Download Link: | Click here to download PDF File Size: 1468 KB |
| Title: | ABOUT THE STUDY IN THE TIME DOMAIN OF JUNCTIONS BETWEEN THIN WIRES |
| Abstract: | DOTIGl is a computer code developed for the study of the interaction of arbitrary electromagnetic signals with thin-wire structures, in the time domain. It calculates the current distribution induced on the structure by solving the electric field integral equation using the moment method. The numerical procedure used to develop the program and different possibilities for treating junctions are briefly described. To obtain an accurate solution for the current induced on the thin-wire structures it is very important to pay attention to the zones at which the wires intersect. Thus, different junction treatments were tested for several simple structures. Following some convergence criteria the current distributions were compared to a reference solution and also, by way of Fourier transform, with results obtained using some well known frequency-domain codes. [Vol. 6, No. 2, pp. 2-20 (199l)] |
| Author(s): | Amelia Rubio Bretones, Alfonso Salinas Extremera, Amelia Rubio Bretones, Alfonso Salinas Extremera |
| File Type: | Journal Paper |
| Issue: | Volume: 6 Number: 2 Year: 1991 |
| Download Link: | Click here to download PDF File Size: 567 KB |
| Title: | THE SHORT FAT DIPOLE DEVELOPMENT IN APL OF A MOM SOLUTION |
| Abstract: | This paper describes an effort to find the best profile for a figure-of- revolution, center-fed, electrically small dipole. It includes presentations on equation development, singularity treatment, code development, verification, and performance. [Vol. 6, No. 2, pp. 99-132 (1991)] |
| Author(s): | Douglas B. Miron, Douglas B. Miron |
| File Type: | Journal Paper |
| Issue: | Volume: 6 Number: 2 Year: 1991 |
| Download Link: | Click here to download PDF File Size: 1697 KB |
| Title: | ANALYSIS OF THREE DIMENSIONAL DIELECTRIC LOADED CAVITIES WITH EDGE ELEMENTS |
| Abstract: | In this paper we show that edge elements (a class of mixed finite elements) provide an efficient numerical approach in the determination of resonant modes in three dimensional high frequency cavities. These finite elements avoid "spurious modes", the non-physical numerical fields obtained from the solution of eigenvalue problems. Here, empty cavities as well as dielectric loaded cavities are analyzed: no "spurious mode" was observed. Moreover, comparisons with analytical results and previously published ones show the great accuracy of the numerical technique. [Vol. 6, No. 2, pp. 133-142 (1991)] |
| Author(s): | L. Pichon, A. Razek, L. Pichon, A. Razek |
| File Type: | Journal Paper |
| Issue: | Volume: 6 Number: 2 Year: 1991 |
| Download Link: | Click here to download PDF File Size: 1475 KB |
| Title: | ANTENNA ARRAY MODELLING BY PARALLEL PROCESSOR FARMS |
| Abstract: | The fast concurrent implementation of a FORTRAN method of moments analysis of the electromagnetic properties of an array of tapered slot antennae is discussed. Decomposition of an existing FORTRAN algorithm for calculation of the currents induced by an incident radiation field in an infinite array of tapered slot antennae is described. The problem was distributed across an array of INMOS transputers, yielding significant speed-up over a single CPU. This decomposition was relatively simple to implement, can readily be scaled to larger processor arrays virtually indefinitely, and promises linear speed-up with the number of processors in the array. [Vol. 6, No. 2, pp. 143-151 (l991)] |
| Author(s): | Iain Cramb, Daniel H. Schaubert, Richard Beton, James Kingdon, Colin Upstill, Iain Cramb, Daniel H. Schaubert, Richard Beton, James Kingdon, Colin Upstill |
| File Type: | Journal Paper |
| Issue: | Volume: 6 Number: 2 Year: 1991 |
| Download Link: | Click here to download PDF File Size: 1473 KB |
| Title: | THE EOUIVALENT CIRCUIT OF A MICROSTRIP CROSSOVER |
| Abstract: | The equivalent circuit of a microstrip crossover is found. Integral equations are obtained for the densities of excess charge, and these equations are solved by the method of moments. Introduction of a specified transverse distribution of charge, which satisfies the edge condition, reduces the computing time dramatically while the accuracy remains excellent. Several plots of the excess charge densities are provided along with numerical values of lumped excess capacitances. [Vol. 4, No. 1, pp. 69-95 (1989)] |
| Author(s): | Stilianos Papatheodorou, Roger F. Harrington, Joseph R. Mautz, Stilianos Papatheodorou, Roger F. Harrington, Joseph R. Mautz |
| File Type: | Journal Paper |
| Issue: | Volume: 4 Number: 1 Year: 1989 |
| Download Link: | Click here to download PDF File Size: 573 KB |
| Title: | AN ANISOTROPIC TWO-DIMENSIONAL SCATTERING CODE |
| Abstract: | A computer code has been developed to predict radar return from two- dimensional cylindrical targets composed of anisotropic, lossy, and inhomogeneous materials. A moment method formulation uses point matching with rectangular domains of pulse basis functions for volumetric elements. Targets may also be composed of thin films including conducting sheets. Particular attention is paid to problems associated with close coupling which involve numerical integration over neighboring domains of basis functions, rectangles which may be very close together as in the case of thin layers of material. Examples are used to show that analytical integration of singularities associated with close coupling gives results which are superior to the numerical approximations used in typical moment method The results are of interest for problems involving isotropic as well as anisotropic targets. For example, when a code which calculates close couplings with numerical approximations is applied to a hollow, conducting cylinder, computed radar return may be distorted by introducing conducting elements close to the interior wall of the cylinder. With analytical treatment of singularities, however, there is no distortion. In another example results from codes are compared for the case of a right circular cylinder coated with anisotropic material. Results in good agreement with a series solution taken from the literature are achieved when analytical treatment of singularities is considered. Finally, for the example of a conducting plate it is shown how analytical treatment of singularities makes good results possible for a minimum number of basis functions. [Vol. 4, No. 2, pp. 49-58 (1989)] |
| Author(s): | J. P. Heaton, J. P. Heaton |
| File Type: | Journal Paper |
| Issue: | Volume: 4 Number: 2 Year: 1989 |
| Download Link: | Click here to download PDF File Size: 548 KB |
| Title: | EFFICIENT SOLUTION OF LARGE MOMENTS PROBLEMS: WIRE GRID MODELING CRITERIA AND CONVERSION TO SURFACE CURRENTS |
| Abstract: | A banded matrix iterative solution method for linear simultaneous equations arising from thin wire moments problems has been applied to a variety of problems of intermediate electrical size with the number of unknowns ranging up to 1000. Using a convergence criterion of 1 percent, solution efficiencies varied from 2.5 for short, fat objects up to 35 for long, thin objects. Application of the method requires some expertise. Approximate guidelines for wire grid modeling of surfaces have been developed for the moments formalism used. A new method for computing surface currents from grid currents is discussed. [Vol. 3, No. 1, pp. 55-81 (1988)] |
| Author(s): | Thomas R. Ferguson, Robert J. Balestri, Thomas R. Ferguson, Robert J. Balestri |
| File Type: | Journal Paper |
| Issue: | Volume: 3 Number: 1 Year: 1988 |
| Download Link: | Click here to download PDF File Size: 2327 KB |
| Title: | MODIFICATION TO MININEC FOR THE ANALYSIS OF WIRE ANTENNAS WITH SMALL RADIUS TO WAVELENGTH RATIO |
| Abstract: | MININEC is a useful and compact method of moments antenna program, but MININEC does not give reasonable values for the input reactance of very thin wires at low frequencies. This problem greatly restricts the use of MININEC in the design and analysis of VLF and LF antennas. A modification to the program which eliminates this restriction is discussed. The modification consists of treating both the source and observation segments as filaments and only considering the wire radius when computing the self-impedance. A listing of the changed computer code is included. [Vol. 1, No. 1, pp. 29-31 (1986)] |
| Author(s): | Todd D. Poston, Stephen W. Kershner, Todd D. Poston, Stephen W. Kershner |
| File Type: | Journal Paper |
| Issue: | Volume: 1 Number: 1 Year: 1986 |
| Download Link: | Click here to download PDF File Size: 367 KB |
| Title: | OPTIMISATION AND LARGE SCALE COMPUTATION IN INTEGRAL EQUATION SCATTERING ANALYSES |
| Abstract: | The kinds of difficulties posed by large scattering computations change as larger problems are addressed. Unfavourable cost scalings make the performance of small, core, portions of code dominant, and require that they, and the overall code structure, be optimised for large scale computation. This is discussed in the context of rcs and scattering computations of multi-wavelength bodies using a time domain integral equation treatment. Examples presented include the NASA almond evaluated at 25 wavelengths long, and an assembly of 101 spherical scatterers of ~1/2 wavelength diameter each, occupying a volume of side ~250 wavelengths. |
| Author(s): | S. J. Dodson, S. P. Walker, M. J. Bluck, S. J. Dodson, S. P. Walker, M. J. Bluck |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 2 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 2480 KB |
| Title: | BANDWIDTH REDUCED FULL-WAVE SIMULATION OF LOSSLESS AND THIN PLANAR MICROSTRIP CIRCUITS |
| Abstract: | We present a full-wave, high-performance, numerical scheme for the analysis of planar microstrip circuits which is based on an efficient electromagnetic formulation of the field problem and on the bandwidth reduction of the discretized sparse matrix. The above mentioned electromagnetic efficiency is at-tained by considering a Mixed Potential Integral Equa-tion (MPIE) with the kernel expressed by closed-form spatial-domain Green’s functions; as a consequence, the reaction integrals are evaluated by using just one-dimensional numerical integration over a finite spatial do-main. Moment method discretization of the MPIE leads to the corresponding matrix problem. The accurate analysis of the matrix properties shows that a sparsity of 70-85% in the discretized linear system can be routinely enforced without significantly altering the solution accuracy. A new scheme for the sparse matrix bandwidth reduc-tion, particularly tailored for electromagnetic problems, can be therefore introduced, leading to considerable re-ductions of the simulation time. Results are presented demonstrating that the use of a bandwidth reduction strategy coupled with efficient problem-matched Green’s functions allows as to obtain speed-ups in simulation time of more than one order of magnitude with respect to stan-dard state of the art implementations. |
| Author(s): | A. Caproni, F. Cervelli, M. Mongiardo, L. Tarricone, F. Malucelli, A. Caproni, F. Cervelli, M. Mongiardo, L. Tarricone, F. Malucelli |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 2 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 1033 KB |
| Title: | A STABILIZING SCHEME FOR THE EXPLICIT TIME-DOMAIN INTEGRAL-EQUATION ALGORITHM |
| Abstract: | The stability of the explicit version of the solution of the time-marching electric-field integral-equation continues to depend on the specifics of the application. The design of stability-enhancing schemes seems to be more of an art than a science. A contribution to this art is made with a design that is stable where others are not, and the practical issues of implementation, accuracy, and efficiency in both time and memory are addressed. |
| Author(s): | S. Kashyap, M. Burton, A. Louie, S. Kashyap, M. Burton, A. Louie |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 3 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 757 KB |
| Title: | AN ALGORITHM FOR CALCULATING GREEN’S FUNCTIONS OF PLANAR, CIRCULAR CYLINDRICAL, AND SPHERICAL MULTILAYER SUBSTRATES |
| Abstract: | We introduce an algorithm for calculating spectral domain Green’s functions of planar, circular, cylindrical, and spherical multilayer structures. The three spectral domain problems are interpreted as multilayer spatial domain problems with electromagnetic sources in the forms of current sheets, tubes, and shells, respectively, and with harmonic spatial variation. The algorithm, which is the same for all three geometries, is based on dividing these three field problems into appropriate subproblems by using equivalence, and on determining the tangential field components at the interfaces between the layers of the structure. The algorithm is implemented into three versions of a Fortran routine called G1DMULT, one version for each geometry. The only difference between the three versions is in two subroutines which calculate the fields due to harmonic current sheets, tubes, and shells, respectively, located in an infinite homogeneous material. We have tested the routine by calculating the properties of microstrip patch antennas and periodic structures. |
| Author(s): | Zvonimir Šipuš, Per-Simon Kildal, Robert Leijon, Martin Johansson, Zvonimir Šipuš, Per-Simon Kildal, Robert Leijon, Martin Johansson |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 3 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 955 KB |
| Title: | EFFICIENT CGM APPLICATION FOR SCATTERING AND RADIATION OF ANTENNAS ON BOARD ARBITRARY STRUCTURES |
| Abstract: | A technique based on an iterative scheme and a current-based method has been developed to determine the scattering and propagation characteristics of arbitrary structures and environments. To obtain a high degree of accuracy, parametric surfaces (NURBS) have been used to model the body surface. The technique solves the MFIE (Magnetic Field Integral Equation) defined over the body surface. The aim of the method is to make the analysis avoiding the memory and CPU time restrictions imposed by low frequency methods such as Method of Moments. Approximate expressions, based on dipole moment formulations, are applied to speed-up the calculations. Two initial guesses for the CGM (Conjugate Gradient Method) have been compared in order to see which one presents the best relationship between convergence and CPU time. Results are presented showing the behavior of the developed methods comparing them with measurements and other electromagnetic methods |
| Author(s): | Olga M. Conde, Manuel F. C, Olga M. Conde, Manuel F. C |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 3 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 741 KB |
| Title: | IMPLICITNESS AND STABILITY OF TIME DOMAIN INTEGRAL EQUATION SCATTERING ANALYSES |
| Abstract: | Time domain integral equation analysis of scattering problems has been inhibited by the instability generally observed. Usual treatments are explicit. We here describe an implicit approach, which allows timesteps to be selected to model the temporal variation of the field, rather than being constrained to small values by the need for the wave propagation during a timestep to be less than the smallest nodal spacing. For realistic bodies, this alone can result in computational cost savings by a significant factor. We present an investigation of the stability of the implicit approach, and show that it is much less prone to instability than the explicit. For realistic bodies, with rationally chosen timesteps, the implicit approach is for all practical purposes stable. This is so without recourse to the various temporal averaging schemes which have been proposed for stabilisation of the explicit form. |
| Author(s): | S. J. Dodson, S. P. Walker, M. J. Bluck, S. J. Dodson, S. P. Walker, M. J. Bluck |
| File Type: | Journal Paper |
| Issue: | Volume: 13 Number: 3 Year: 1998 |
| Download Link: | Click here to download PDF File Size: 778 KB |
| Title: | A USER-FRIENDLY COMPUTER CODE FOR RADIATED EMISSION AND SUSCEPTIBILITY ANALYSIS OF PRINTED CIRCUIT BOARDS |
| Abstract: | A user-friendly computer code, PCB-MoM, that is intended to be used in EMC applications for predicting radiated emission and susceptibility of printed circuit boards (PCB) is presented. The formulation is based on an electric field integral equation (EFIE) expressed in the frequency domain. The EFIE is solved by the method of moments using two-dimensional pulse bsis functions and one-dimensional pulse test functions. In order to incorporate dielectric material in the substrate a spectral domain formulation is used. The code has been validated by comparison with previously published results and results obtained by other methods and codes. |
| Author(s): | J. Carlsson, P-S. Kildal, J. Carlsson, P-S. Kildal |
| File Type: | Journal Paper |
| Issue: | Volume: 14 Number: 1 Year: 1999 |
| Download Link: | Click here to download PDF File Size: 609 KB |
| Title: | A NOVEL SPATIAL IMAGES TECHNIQUE FOR THE ANALYSIS OF CAVITY BACKED ANTENNAS |
| Abstract: | This paper describes a new contribution to the analysis of arbitrary shielded circuits and antennas of complex shapes, in the frame of the intergal equation (IE) and Method of Moments formulation (MoM). The technique is based on the spatial image approach and a new specially truncated set of images is developed to enhance the convergance behavior of the series involved. Results show that, with the new specially truncated series of images, convergence is achieved very fast. In this paper simulated results obtained with the new approach are compared with measurments. |
| Author(s): | A.A. Melcon, J.R. Mosig, A.A. Melcon, J.R. Mosig |
| File Type: | Journal Paper |
| Issue: | Volume: 14 Number: 3 Year: 1999 |
| Download Link: | Click here to download PDF File Size: 575 KB |
| Title: | A Genetic Approach for the Efficient Numerical Analysis of Microwave Circuits |
| Abstract: | The development of effiecient and effective algoritms for sparse matrix bandwidth minimization is of paramount importance for the enhancement of many numerical techinques for the analysis of microwave circuits. The tast of bandwidth reduction is computationally hard. Several approaches have already been proposed, but the problem is still open. In this paper, a genetic solution is proposed. The genetic algorithm is described, as well as its main characteristics (choice of chromosomes, genetic operations, etc.). Results demonstrate that the advantages of the genetic approach vanish because of the huge computational effort required. This severe limitation is removed thanks to the natural amenability of genetic algorithms to a parallel implementation. Results in the paper prove that a parallel genetic approach is a state-of-the-art solution to the problem of bandwidth reduction of sparse matrices encountered in electromagnetic numerical methods. |
| Author(s): | Luciano Tarricone, Luciano Tarricone |
| File Type: | Journal Paper |
| Issue: | Volume: 15 Number: 2 Year: 2000 |
| Download Link: | Click here to download PDF File Size: 6607 KB |
| Title: | A New Excitation Model For Probe-Fed Printed Antenna On Finite Size Ground Planes |
| Abstract: | This paper presents a new excitation model for probe-fed printed antennas on both infinite and finite size ground planes. The model has been developed within the general frame of the mixed potential integral equation (MPIE) and the method of moments (MoM). The technique is based on a delta-gap voltage model, and a special procedure is implemented inside the integral equation to effecitivly impose a voltage reference plane into a floating metallic plate which is acting as a ground plane. The present technique allows the accurate calculation of the input impedance of printed antennas, and the effects of finite size ground planes can be easily accounted for in the calculations. In addition, an efficient technique is present for the evaluation of the radiation patterns of printed antennas, taking also into account the presence of the finite size ground plane. Comparisons with measured results show that the new derived excitation method is indeed accurate, and can be used for the prediction of the backside radiation and sidelobe levels of real life finite ground plane printed antennas. |
| Author(s): | F. Tiezzi, A. Alvarez-Melcon, Juan R. Mosig, F. Tiezzi, A. Alvarez-Melcon, Juan R. Mosig |
| File Type: | Journal Paper |
| Issue: | Volume: 15 Number: 2 Year: 2000 |
| Download Link: | Click here to download PDF File Size: 5422 KB |
| Title: | A General Method for the Ray-Tracing on Convex Bodies. |
| Abstract: | A method to compute the ray tracing over complex bodies composed by smooth convex surfaces of arbitrary shape is presented. The bodies are assumed to be electrically large and perfectly conducting. Free-form parametric surfaces are used to describe the structures. The technique is simple and efficient, so it is suitable for complex bodies. Some results obtained with FASANT code, which implements this technique, are presented to prove the efficiency of the method. |
| Author(s): | F. Saez de Adana, E. Gonzalez, O. Gutierrez, J. Perez, M. F. Catedra, F. Saez de Adana, E. Gonzalez, O. Gutierrez, J. Perez, M. F. Catedra |
| File Type: | Journal Paper |
| Issue: | Volume: 16 Number: 1 Year: 2001 |
| Download Link: | Click here to download PDF File Size: 540 KB |
| Title: | FDTD Time Domain Near- to Far-Zone Transformation Above a Lossy Dielectric Half-Space |
| Abstract: | Near- to Far-zone transformations in the Finite-Difference Time-Domain (FDTD) method can be performed in either the time domain or in the freuency domain. For free space conditions, the time domain near- to far-zone transformation is generally much faster and more memory efficient to use, when we require results at a large number of frequency points at a small number of far-zone directions. However when a lossy dielectric half-space is present, representing the ground, the frequency domain transformation has been favored since the Green's functions involved are relatively simple to express the frequency domain compared with the efforts needed to transform the equivalent currents into the frequency domain. This paper describes a combined time and frequency domain near- to far-zone transformation above a lossy dielectric half-space, where it is not necessary to transform the equivalent currents into the frequency domain. This transformation is much faster than the pure frequency domain transformation and comparisons are made between the two different approaches. For validation purposes, scattering of a dihedral above a lossy dielectric half-space is considered. |
| Author(s): | Torleif Martin, Lars Pettersson, Torleif Martin, Lars Pettersson |
| File Type: | Journal Paper |
| Issue: | Volume: 16 Number: 1 Year: 2001 |
| Download Link: | Click here to download PDF File Size: 865 KB |
| Title: | Difficulties Encountered When Attempting to Validate Thin-Wire Formulations for Linear Dipole Antennas |
| Abstract: | When analyzing wire antennas, the "thin-wire" kernel is often used as a convenient approximation to the exact singular kernel in the electric-field integral equation. In this paper, it is shown that the thin-wire kernel is a poor approximation to the true kernel, but its use does yield good values for input impedance over a significant range of parameters (e.g., wire radii, size of subsectional cells). The validity of the thin-wire kernel when used within the electric field integral equation appears to be due to the fact that the approach is often a good approximation to the Extended Boundary Condition (EBC) formulation. Although it is often implied in the literature that use of the thin-wire kernel will produce "convergent" values for input impedance, in actuality there is no guarantee that results improve as more cells are taken along the wire. Despite widespread use of the "thin-wire" kernel, there are inherent difficulties in the validation of codes based on this approximation. |
| Author(s): | A. F. Peterson, A. F. Peterson |
| File Type: | Journal Paper |
| Issue: | Volume: 4 Number: 3 Year: 1989 |
| Download Link: | Click here to download PDF File Size: 913 KB |
| Title: | The Comparison of a Time-Domain Numerical Code (DOTIG1) with Several Frequency-Domain Codes Applied to the Case of Scattering From a Thin-Wire Cross |
| Abstract: | In this paper we compare, via Fourier transform, results obtained using the DOTG1 time-domain numerical code with those obtained using several frequency-domain thin-wire codes [1] and with the experimental measurements obtained by Burton [2], specifically applied to the scattering from a cross. |
| Author(s): | A.R. Bretones, A. Salinas, R. Gomez Martin, A. Perez, A.R. Bretones, A. Salinas, R. Gomez Martin, A. Perez |
| File Type: | Journal Paper |
| Issue: | Volume: 4 Number: 3 Year: 1989 |
| Download Link: | Click here to download PDF File Size: 307 KB |
| Title: | Hybrid Integral Equation and Finite Difference Method for Low-Frequency Electric Induction |
| Abstract: | Recently developed fast integral equations solution methods allow for the treatment of electrostatic problems involving perfect conductors of complicated shape. Using the precepts of Stevenson's method, external electrostatic solutions can be used in the solution of internal low frequency electric induction problems in electrically small isolated compact conducting bodies. A precorrected FFT algorithm is implemented to solve the electrostatic problem of an isolated human body situated in an external field. The resulting induced fields. It is shown that the resulting hybid cody produces results that are in excellent agreement with those produced by other methods, while being significantly more effiecient in terms of computer memory and time resources |
| Author(s): | Trevor W. Dawson, Sanjay Velamparambil, Maria A. Stuchly, Trevor W. Dawson, Sanjay Velamparambil, Maria A. Stuchly |
| File Type: | Journal Paper |
| Issue: | Volume: 16 Number: 3 Year: 2001 |
| Download Link: | Click here to download PDF File Size: 1015 KB |
| Title: | A Model of finite electrodes in layered biological media: hybrid image series and moment method scheme |
| Abstract: | The low-frequency electromagnetic field interaction with layered biological tissue is investigated for electrode array excitation. The problem may be reduced into a system of P (number of electrodes) Fredholm integral equations of the first kind for the electrodes' current distribution. We have shown that the kernel (Green's function) of each integral equation can be expressed by image series. This leads to a most effective inversion of the integral equation system via the moment method, since the moment matrix elements can be expressed explicitly by image series. The outlined procedure is simple to implement and allows estimation of the distributions of low-frequency potential, current, field and power within the multilayer tissue. It may serve as a simplified first-order prototype model for realistic biomedical problems where the dependence on the number of electrodes, tissue layers and their electrical properties must be accounted for. The model has been utilized for the calculation of the electrode array impedance matrix, potential fields, intra-muscular current distributions and isometric recruitment curves (IRC). The simulation results indicate that the IRCs are insensitive to the electrodes' size, however, the inclusion of the bone/fascia layer significantly increases the IRC slope. Furthermore, the simulation scheme, which can be readily implemented for the classification, calibration, verification and interpretation of reported numerical and experimental biomedical data, is also applicable in other problem areas such as geophysical prospecting and electrode grounding in power systems. |
| Author(s): | Leonid M. Livshitsz, Pinchas D. Einziger, Joseph Mizrahi, Leonid M. Livshitsz, Pinchas D. Einziger, Joseph Mizrahi |
| File Type: | Journal Paper |
| Issue: | Volume: 16 Number: 2 Year: 2001 |
| Download Link: | Click here to download PDF File Size: 842 KB |
| Title: | EVALUATION OF MODELING ACCURACY OF POWER FREQUENCY FIELD INTERACTION WITH THE HUMAN BODY |
| Abstract: | Heterogeneous voxel models of the human body are used in numerical computations of induced electric fields in tissues. Various numerical methods are used for electric and magnetic field sources under quasi-static conditions. Validation of the computational methods and detailed estimation of errors associated with the modeling are given. Analytic solutions for spheres (homogeneous and layered) and other simple models are used to evaluate modeling accuracy. Sources of inherent errors associated with voxel models (staircase approximation of smooth surfaces) are identified, and methods are presented that decrease the errors. |
| Author(s): | T. W. Dawson, M. Potter, M. A. Stuchly, T. W. Dawson, M. Potter, M. A. Stuchly |
| File Type: | Journal Paper |
| Issue: | Volume: 16 Number: 2 Year: 2001 |
| Download Link: | Click here to download PDF File Size: 927 KB |
| Title: | CALCULATIONS OF ELECTRIC FIELDS IN THE HUMAN KNEE PRODUCED BY A KNEE-THIGH ELECTRODE PAIR |
| Abstract: | Calculations of the electric fields produced in the cartilage of the human knee by a knee-thigh electrode pair excited by a low-frequency voltage waveform are presented and discussed. The simulations were performed using a three-dimensional finite-difference frequency-domain technique based upon an equivalent circuit model for solving Maxwell's equations. The leg model used in these calculation was obtained from the anatomically segmented human-body model of Gandhi. The calculated average electric fields within the medial and lateral cartilage were found to be 2.92 V/m and 2.51 V/m respectively for a voltage excitation of one volt at a frequency of 1 kHz applied between the electrodes. A special truncation technique, which incorporates information from a physically larger coarse model in the excitation of a finer subsection of the model, was utilized to obtain higher resolution results in the region of interest. |
| Author(s): | D. N. Buechler, D. A. Christensen, C. H. Durney, B. J. Simon, D. N. Buechler, D. A. Christensen, C. H. Durney, B. J. Simon |
| File Type: | Journal Paper |
| Issue: | Volume: 16 Number: 2 Year: 2001 |
| Download Link: | Click here to download PDF File Size: 803 KB |
| Title: | NUMERICAL ANALYSIS OF THE "FERRIS WHEEL" MICE EXPOSURE SYSTEM USING AN EFFICIENT CYLINDRICAL FDTD SCHEME |
| Abstract: | The objective of this study is to develop a numerical tool for characterizing the "ferris wheel" exposure system employed in a long-term study of RF exposure on mice [5]. The "ferris wheel" is a radial cavity loaded with forty mice around its perimeter. In order to exploit the angular periodicity of the radial exposure system, we developed a Finite Difference in Time Domain (FDTD) code based on a cylindrical grid to analyze a single angular sector of the 40-mouse "ferris wheel". The singularity of the Maxwell equations in the cylindrical FDTD scheme was appropriately removed, and other suitable expedients were implemented to reduce simulation time and memory requiremnts. In order to estimate RF leakage, the actual openings in the radial cavity, needed to insert the mice, were considered as well. The FDTD scheme incorporates the perfectly matched layer (PML) unsplit formulation (anisotropic medium), as absorbing boundary condition. The code was validated with measurements, showing good agreement. A criterion for assessing the uniformity of the exposure is presented, together with results at 900 MHz and 1.8 GHz. |
| Author(s): | P. Russo, A. Faraone, P. Russo, A. Faraone |
| File Type: | Journal Paper |
| Issue: | Volume: 16 Number: 2 Year: 2001 |
| Download Link: | Click here to download PDF File Size: 1077 KB |
| Title: | Antennas on dielectric coated convex surfaces : theory and experimentations |
| Abstract: | The purpose of this paper is to analyze the diffraction phenomenon introduced by perfectly conducting convex surfaces with dielectric coating, resulting from an interaction of these structures with an electromagnetic radiation created essentially by sources which are set on these objects at high frequencies. |
| Author(s): | M. -A. Blondeel-Fournier, W. Tabbara, L. Beaulieu, M. -A. Blondeel-Fournier, W. Tabbara, L. Beaulieu |
| File Type: | Journal Paper |
| Issue: | Volume: 6 Number: 1 Year: 1991 |
| Download Link: | Click here to download PDF File Size: 1033 KB |
| Title: | Modified Fresnel Coefficients for Huygens' Sources in FDTD |
| Abstract: | Scattering of electromagnetic fields from objects on or beneath the ground can be analyzed with the Finite-Difference Time-Domain (FDTD) method. The equivalence principle can be utilized for generation of incident plane waves where the Fresnel reflection and refraction coefficients are multiplied by the pulse spectrum in the frequency domain and the result is transformed into the time-domain. Errors will appear in the Huygens' sources due to numerical dispersion where the main errors come from the use of analytical reflection and refraction coefficients. Their influence on the accuracy is generally negligible for applications where the scattered field from the object is greater than the numerical errors introduced. However, if weak scattering events are considered, such as for objects buried in ground, the dispersion errors can be of the same order of magnitude as the scattered field. In this paper we derive the modified Fresnel coefficients for a homogeneous lossy ground which are consistent with the FDTD algorithm and can be used in the Huygens' sources for suppressing numerical errors. It is shown that the modified Fresnel coefficients reduces the noise level for an empty FDTD volume with 30 to 60 dB. As an application example, the far-zone scattering of a buried dipole is considered. |
| Author(s): | Torleif Martin, Lars Pettersson, Torleif Martin, Lars Pettersson |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 1 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 351 KB |
| Title: | The Stabilized Biconjugate Gradient Fast Fourier Transform Method for Electromagnetic Scattering |
| Abstract: | An iterative method, the stabilized biconjugate gradient (BiCGSTAB) method, combined with the fast Fourier transform (FFT) for solving electromagnetic scattering problems is developed for the 3-D volume electric field integral equation. It converges significantly faster than the conventional conjugate gradient (CG) and biconjugate gradient (BiCG) fast Fourier transform methods. With this BCGS-FFT method, we can solve a large-scale volume integral equation with $20$ million unknowns on a single CPU workstation. |
| Author(s): | Xue Min Xu, Qing Huo Liu,, Zhong Qing Zhang, Xue Min Xu, Qing Huo Liu,, Zhong Qing Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 1 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 235 KB |
| Title: | Reducing Electromagnetic Coupling in Shielded Enclosures using a Genetic Algorithm -- Finite-Difference Time-Domain Solver |
| Abstract: | Comprehensive shielding in modern electronic equipment may lead to resonant behaviour within the equipment enclosure. This paper presents a method for optimising the placement of sources of electromagnetic (EM) energy and susceptors to this EM energy within an enclosed resonant cavity. The source and susceptor are placed on a dielectric slab within a perfectly conducting enclosure to reduce the level of EM coupling between the two. Optimisation is facilitated using a genetic algorithm coupled with a finite-difference time-domain solver. Results are presented for single objective optimisation and multi-objective optimisation cases. |
| Author(s): | Russell Iain Macpherson, N J Ryan, R. I. Macpherson, N. J. Ryan, Russell Iain Macpherson, N J Ryan, R. I. Macpherson, N. J. Ryan |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 3 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 1130 KB |
| Title: | COUPLING 2D FINITE ELEMENT MODELS AND CIRCUIT EQUATIONS USING A BOTTOM-UP METHODOLOGY |
| Abstract: | The aim of this paper is to present an approach, able to deal with all possible connections of voltage and current sources and impedances, combining conductors in which the skin effect is taken into account and conductors in which skin effect is neglected. This approach is obtained using a bottom-up methodology. In this way, the meaning of terms in the generalized approach is naturally inherited from some specific problems. This model is presented in a compact form, preserving sparse, symmetric and positive-definiteness matrices. The vectors and matrices, computed during the solution stage, are employed in engineering calculations as current and inductance computations providing compact expressions suitable for efficient algorithms. Finally, the proposed approach, implemented in a FEM software package developed by the authors, is applied to the study of a three-phase transformer, supplied with a balanced three-phase voltage (sinusoidal and nonsinusoidal) and loaded with an unbalanced three-phase RL impedance. The agreement between the computed and experimental results shows the validity of the proposed model and its implementation. |
| Author(s): | Emilio Gomez Lazaro, Jose Roger-Folch, Antonio Gabaldon Marin, Angel Molina Garcia, Emilio Gomez Lazaro, Jose Roger-Folch, Antonio Gabaldon Marin, Angel Molina Garcia |
| File Type: | Journal Paper |
| Issue: | Volume: 17 Number: 3 Year: 2002 |
| Download Link: | Click here to download PDF File Size: 331 KB |
| Title: | Application of Two-Dimensional AWE Algorithm in Training Multi-Dimensional Neural Network Model |
| Abstract: | Artificial neural network (ANN) plays very important role in microwave engineering. Training a neural network model is the key of neural network technique. The conventional methods for training, such as method of moment (MoM), are time-consuming when the training parameters are a bit more. In order to aid the training process by reducing the amount of costly and time-consuming sampling cycles, a lot of algorithms have been developed, such as asymptotic waveform evaluation (AWE). In this paper, MoM in conjunction with the two-dimensional AWE is applied to accelerate the process of training the neural network model based on the input impedance response on frequency and that on other parameters of a microstrip antenna. In AWE method, the derivatives of Green’s function are required. A closed form of microstrip Green’s function is used for this requirement. Then, the derivative matrices respect to both frequency and permittivity can be obtained from the original matrix. With these matrices in hand, coefficients of the two-dimensional Padé polynomial can be obtained. So the sampling data for training neural network model can be obtained and the process of training neural net model can be completed quickly and accurately. Numerical results demonstrate the efficiency of this technique. |
| Author(s): | Y. Xiong, D. G. Fang, R. S. Chen, Y. Xiong, D. G. Fang, R. S. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 2 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 324 KB |
| Title: | Reducing Electromagnetic Coupling in Shielded Enclosures using a Genetic Algorithm -- Finite-Difference Time-Domain Solver |
| Abstract: | Comprehensive shielding in modern electronic equipment may lead to resonant behaviour within the equipment enclosure. This paper presents a method for optimising the placement of sources of electromagnetic (EM) energy and susceptors to this EM energy within an enclosed resonant cavity. The source and susceptor are placed on a dielectric slab within a perfectly conducting enclosure to reduce the level of EM coupling between the two. Optimisation is facilitated using a genetic algorithm coupled with a finite-difference time-domain solver. Results are presented for single objective optimisation and multi-objective optimisation cases. |
| Author(s): | Russell Iain Macpherson, N J Ryan, R. I. Macpherson, N. J. Ryan, Russell Iain Macpherson, N J Ryan, R. I. Macpherson, N. J. Ryan |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 3 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 1809 KB |
| Title: | On the Construction and Use of Two-Dimensional Wavelet-Like Basis |
| Abstract: | An alternative method for generating higher dimensional wavelet-like basis functions is proposed in this paper. One method that has been used was to derive the two-dimensional wavelet-like basis from the two-dimensional traditional finite element basis. However, in this paper, products of one-dimensional wavelet-like functions are used as two-dimensional waveletlike basis functions. The generation of linear wavelet-like functions is discussed in detail and the use of linear and higher order wavelet-like functions is also investigated. The advantages and disadvantages of this technique for deriving wavelet-like basis functions will be discussed. |
| Author(s): | W. E. Hutchcraft, R. K. Gordon, W. E. Hutchcraft, R. K. Gordon |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 3 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 286 KB |
| Title: | EM Modeling of Surfaces with Stop or Go Characteristics – Artificial Magnetic Conductors and Soft and Hard Surfaces |
| Abstract: | |
| Author(s): | Per-Simon Kildal, Ahmed Kishk, Per-Simon Kildal, Ahmed Kishk |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 1 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 626 KB |
| Title: | Theoretical and Experimental Investigations of the Surge Response of a Vertical Conductor |
| Abstract: | |
| Author(s): | Md. Osman Goni, Hideomi Takahasi, Md. Osman Goni, Hideomi Takahasi |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 1 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 484 KB |
| Title: | A Rationale for p-refinement with the Vector Helmholtz Equation and Two Dimensional Vector Finite Elements |
| File Type: | Journal Paper |
| Issue: | Volume: 19 Number: 2 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 175 KB |
| Title: | Generalization of Surface Junction Modeling for Composite Objects in an SIE/MoM Formulation Using a Systematic Approach |
| Abstract: | This paper discusses the modeling of various kinds of surface junctions in an SIE/MoM formulation applied to complex objects consisting of arbitrarily shaped conducting and dielectric bodies. Methods of describing various types of junctions and systematically incorporating them in numerical solutions are presented. The procedures are of interest for the specific application of arbitrarily shaped dielectric resonator antennas and their associated feed structures and packaging. An E-PMCHWT forumation in conjuction with a moment method procedure using multi-domain RWG basis functions is presented to deal with such general junctions. Some results are verified with the FDTD method. |
| Author(s): | J. Shin, A. W. Glisson, A. A. Kishk, J. Shin, A. W. Glisson, A. A. Kishk |
| File Type: | Journal Paper |
| Issue: | Volume: 20 Number: 1 Year: 2005 |
| Download Link: | Click here to download PDF File Size: 491 KB |
| Title: | Electromagnetic Modeling of an Adaptable Multimode Microwave Applicator for Polymer Processing |
| Abstract: | This paper presents the electromagnetic modeling of a novel adaptable multi-feed multimode cylindrical cavity applicator where the spatial distribution of the electric field can be specified a priori to accomplish a desired processing task. The electric field intensity inside the cavity can be tailored by just varying the power delivered to each port, and the mode-switching can be realized without mechanically adjusting the cavity dimensions. An orthogonal feeding mechanism is developed to reduce the cross coupling between the ports. Numerical simulations are performed for the cavity applicator to verify the theoretical analysis. |
| Author(s): | R. Sun, L. C. Kempel, L. Zong, S. Zhou, M. C. Hawley, R. Sun, L. C. Kempel, L. Zong, S. Zhou, M. C. Hawley |
| File Type: | Journal Paper |
| Issue: | Volume: 20 Number: 1 Year: 2005 |
| Download Link: | Click here to download PDF File Size: 856 KB |
| Title: | High Accuracy Evaluation of the EFIE Matrix Entries on a Planar Patch |
| Abstract: | |
| Author(s): | M. Bibby, A. Peterson, M. Bibby, A. Peterson |
| File Type: | Journal Paper |
| Issue: | Volume: 20 Number: 3 Year: 2005 |
| Download Link: | Click here to download PDF File Size: 279 KB |
| Title: | Numerical Characterization of Cavity-Backed Aperture- Coupled Antenna Problem using Hybrid Finite Element Method (FEM) / Method of Moment (MoM) technique |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Antenna Applications Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 90 KB |
| Title: | Generalized Impedance Boundary Condition Based on the Finite Element Method and Its Applications to Aid RFID Antenna Design |
| File Type: | Conference Paper |
| Issue: | Volume: 30 Years of RWG Basis Functions Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 377 KB |
| Title: | FEM-MTLN Hybridization Technique to Evaluate Electrical Current on Multiconductor Cables inside Enclosures Illuminated by a Plane Wave |
| File Type: | Conference Paper |
| Issue: | Volume: S26 Advances on Time Domain Modeling and Design II Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 309 KB |
| Title: | Efficient Higher Order Finite Element–Moment Method Modeling of 3-D Radiation and Scattering Problems |
| File Type: | Conference Paper |
| Issue: | Volume: High-Performance Finite Element Analysis in CEM Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 362 KB |
| Title: | An Efficient Parallel Hybrid Method of FEM-MLFMA for Electromagnetic Radiation and Scattering Analysis of Separated Objects |
| Abstract: | In order to meet the rapidly increasing demand for accurate and efficient analysis of complex radiating or scattering structures in the presence of electrically large objects, a finite element method (FEM)-multilevel fast multipole algorithm (MLFMA) hybrid method that based on the Finite Element-Iterative Integral Equation Evaluation (FE-IIEE) mesh truncation technique is proposed in this paper. The present method makes use of FEM for the regions with small and complex features and MLFMA for the analysis of the electrically large objects, which ensure the accuracy and applicability of the method are better than most commonly adopted FEM-high frequency technique (HFT) hybrid method. The mutual interactions between regions are taken into account in a fully coupled way through iterative near filed computation process. In order to achieve an excellent performance, both algorithms have been implemented together from scratch, being able to run over multi CPU cores. An efficient parallel FEM domain decomposition method (DDM) solver with exploiting geometrical repetitions is included to drastically reduce memory requirements and computational time in the calculation of large array antenna. Also, the parallel MLFMA is adopted to expedite the near-field information exchange between regions. Through numerical example, the effect of distance between regions on the convergence of the proposed hybrid method is studied, and it is shown that the proposed method converge well even if the distance is equal to 0.05λ. Through comparisons with an in-house higher order method of moments (HOMoM) code and commercial software FEKO, the accuracy and effectiveness of the implemented parallel hybrid method are validated showing excellent performance. |
| Author(s): | S. Zuo, Z. Lin, Z. Yue, D. Garcia Donoro, Y. Zhang, X. Zhao |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 10 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 2043 KB |
| Title: | A Vector Generalized Finite Element-Boundary Integral Formulation |
| File Type: | Conference Paper |
| Issue: | Volume: High-Performance Finite Element Analysis in CEM Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 120 KB |
| Title: | A Novel 3D Hybrid FEM-PO Technique for the Analysis of Scattering Problems |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in CEM Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 207 KB |
| Title: | A Hybrid FEM-GO Approach to Simulate the NSA in an Anechoic Chamber |
| Abstract: | A hybrid FEM-GO method is proposed and a new CAD tool based on it is developed for anechoic chamber simulation. The proposed method can deal with a chamber with arbitrary shape and arbitrary layout of radio absorbing material. The normalized site attenuation values are simulated and match the measurement results well. It is shown that the proposed method is an efficient and effective way for chamber design and simulation. |
| Author(s): | Q. Xu, Y. Huang, X. Zhu, L. Xing, P. Duxbury, J. Noonan |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 11 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 2324 KB |
| Title: | A Compact Single/Dual-Band Printed Inverted-F Type Antenna Structure |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced Computational Techniques for Antenna Design Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 2922 KB |
| Title: | UHF-Band Bandpass Filters With Fully- Reconfigurable Transfer Function |
| File Type: | Conference Paper |
| Issue: | Volume: S54 Tunable RF Filters Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 804 KB |
| Title: | Time-dependent Schrödinger Equation based on HO-FDTD Schemes |
| Abstract: | A high order finite-different time-domain methods using Taylor series expansion for solving time-dependent Schrödinger equation has been systematically discussed in this paper. Numerical characteristics have been investigated of the schemes for the Schrödinger equation. Compared with the standard Yee FDTD scheme, the numerical dispersion has been decreased and the convergence has been improved. The general update equations of the methods have been presented for wave function. Numerical results of potential well in one-dimension show that the application of the schemes is more effective than the Yee’s FDTD method and the higher order has the better numerical dispersion characteristics. |
| Author(s): | M. Zhu, F. F. Huo, B. Niu |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2167 KB |
| Title: | The Complex Frequency-Shifted PML Discontinuous Galerkin Time-Domain Method on Unstructured Meshes |
| File Type: | Conference Paper |
| Issue: | Volume: Finite-Volume and Discontinuous Galerkin Time-Domain Techniques Number: Year: 2008 |
| Download Link: | Login To Download (For Members) File Size: 126 KB |
| Title: | The Application of Sparse Approximate Inverse Preconditioner in the Fast Solution of Volume-Surface Integral Equation |
| File Type: | Conference Paper |
| Issue: | Volume: 2-3-A Integration Methods, Time-Domain and Frequency-Domain Computational Methods Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 245 KB |
| Title: | Strategies for Improving Inverse Methods for Eddy Current NDE Corrosion Characterization |
| File Type: | Conference Paper |
| Issue: | Volume: Computational Electromagnetics for Nondestructive Evaluation Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 73 KB |
| Title: | State-of-the-art Linear Iterative Solvers Based on IDR Theorem for Large Scale Electromagnetic Multiple Scattering Simulations |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Advances in Integral Equations and Fast Methods Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 252 KB |
| Title: | Solutions of Large Integral-Equation Problems with Parallel Preconditioned MLFMA |
| File Type: | Conference Paper |
| Issue: | Volume: Poster Sessions 1 Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 379 KB |
| Title: | Skeletonization Accelerated Solution of Crank-Nicolson Method for Solving Three-Dimensional Parabolic Equation |
| Abstract: | Parabolic equation models discretized with the finite difference method have been extensively studied for a long time. However, several explicit and implicit schemes exist in the literature. The advantage in explicit schemes is its simplicity, while its disadvantage is conditional stability. On the other hand, implicit schemes are unconditionally stable but require special treatment for a fast and accurate solution such as the Crank-Nicolson (CN) method. This method becomes computationally intensive for problems with dense meshes. The resulting matrix from the CN in two and three-dimensional cases requires high computational resources. This paper applies hierarchical interpolative factorization (HIF) to reduce the computational cost of the CN method. Numerical experiments are conducted to validate the proposed HIF acceleration. |
| Author(s): | H. F. Rasool, C. Jun, X.-M. Pan, X.-Q. Sheng |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 9 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1611 KB |
| Title: | Simple Dispersion Analysis of 2nd and 4th order FDTD Schemes |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Finite-Difference Time Domain Modeling Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 57 KB |
| Title: | SDR Based Modulation Performance of RF Signal under Different Communication Channel |
| Abstract: | Hardware components are an integral part of Hardware Define Radio (HDR) for seamless operations and optimal performance. On the other hand, Software Define Radio (SDR) is a program that does not rely on any hardware components for its performance. Both of the latter radio programmers utilize modulation functions to make their core components from signal processing viewpoint. The following paper concentrates on SDR based modulation and their performance under different modulations. The bit error rate (BER) of modulations such as PSK, QAM, and PSAM were used as indicators to test channel quality estimation in planar Rayleigh fading. Though it is not commonly used for channel fading, the method of the adder determines the regionally segmented channel fading. Thus, the estimation error of the channel change substantially reduces the performance of the signal, hence, proving to be an effective option. Moreover, this paper also elaborates that BER is calculated as a function of the sample size (signal length) with an average of 20 decibels. Consequently, the size of the results for different modulation schemes has been explored. The analytical results through derivations have been verified through computer simulation. The results focused on parameters of amplitude estimation error for 1dB reduction in the average signal-to-noise ratio, while the combined amplitude deviation estimation error results are obtained for a 3.5 dB reduction. |
| Author(s): | S. Habib |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2204 KB |
| Title: | Reduced-Order Modeling VFETD/FDTD Schemes for the Optimized Design of 3-D Nanocomposite Structures |
| File Type: | Conference Paper |
| Issue: | Volume: S39 Inverse Finite Element Optimization in Electromagnetic Product Design and Non-Destructive Evaluation I Number: Year: 2015 |
| Download Link: | Login To Download (For Members) File Size: 1274 KB |
| Title: | Rapidly convergent representations for 3D Green’s functions for a linear periodic array in free space and near layered media |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Numerical EM and Propagation Tools Number: Year: 2009 |
| Download Link: | Login To Download (For Members) File Size: 65 KB |
| Title: | Performance Evaluation of State-of-the-Art Linear Iterative Solvers Based on IDR Theorem for Large Scale Electromagnetic Multiple Scattering Simulations |
| Abstract: | The present paper treats with the latest linear iterative solver IDR(s) method and its variants proposed by P. Sonneveld and M. van Gijzen. We derive preconditioned algorithms of the solvers based on right preconditioning and list them. The solvers are numerically tested in terms of convergence and accuracy for the computation of electromagnetic wave scattering from over 104 dielectric cylinders. Consequently, minimization schemes for residual vectors refine not only convergence but also accuracy for the original IDR(s) method. However, a spurious convergence may be confirmed and its influence is 1 or 2 digit error independently of parameter s. |
| Author(s): | N. Nakashima, S. Fujino, M. Tateiba |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 451 KB |
| Title: | Parallel Higher-Order Method of Moments with Efficient Out-of-GPU Memory Schemes for Solving Electromagnetic Problems |
| Abstract: | A distributed parallel Higher-order Method of Moments (HoMoM) for solving electromagnetic problems on CPU/GPU clusters is presented. An MPI/ OpenMP/CUDA parallel framework based on the GPU context technique is designed. An out-of-GPU memory scheme is employed to break the limitation of the GPU memory. To improve the performance of data transferring between main memory and GPU memory, an overlapping scheme based on asynchronous technique and CUDA streams is adopted. In comparison with the parallel CPU version only, numerical results including a metallic airplane and an airborne array with dielectric structures demonstrate the high performance of the proposed method. |
| Author(s): | Z. Lin, Y. Chen, X. Zhao, D. Garcia-Donoro, Y. Zhang, H. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 9 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1747 KB |
| Title: | Parallel High-Order EM-FVTD on an Unstructured Mesh |
| File Type: | Conference Paper |
| Issue: | Volume: Student Paper Competition Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 724 KB |
| Title: | On the Factorization of Potential Functions without Utilizing the Addition Theorem |
| File Type: | Conference Paper |
| Issue: | Volume: Electromagnetic Modeling Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 233 KB |
| Title: | Observed Accuracy of Point-Tested and Galerkin Implementations of the Volume EFIE for Dielectric Targets |
| Abstract: | Galerkin testing in method-of-moments procedures is defined as the use of the same set of functions as both basis functions and testing functions to construct a linear system from a continuous equation. There is a widespread belief that Galerkin testing enhances the accuracy of numerical results, and this has been shown to be true under certain conditions for surface integral equation formulations. This property is investigated for the volume electric field integral equation (EFIE) applied to dielectric bodies. The relative accuracy obtained in internal fields and scattering cross section for Galerkin and for point testing schemes is compared for a variety of target sizes and materials. In many cases, the point-tested results converge at the same rate as the Galerkin results and are more accurate. |
| Author(s): | A. F. Peterson |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 3 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 309 KB |
| Title: | Numerical Examinations of the Stability of FDTD Subgridding Schemes |
| Abstract: | The stability of two-dimensional Finite-Difference Time-Domain subgridding schemes was numerically examined. Both the same-time-step and the multiple-time-step schemes were considered. Results show that the multiple-time-step subgridding scheme is late-time unstable due to larger-than-unity eigenvalues. As to the same-time-step subgridding schemes, stability is related to the treatment of corner regions. |
| Author(s): | S. Wang, S. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 22 Number: 2 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 314 KB |
| Title: | New Stability Criterion for Unstructured Mesh Upwinding FVTD Schemes for Maxwell’s Equations |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 3 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 240 KB |
| Title: | Necessary Stability Criterion for Unstructured Mesh Upwinding FVTD Schemes for Maxwell\'s Equations |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Conformal Time-Domain Methods: Finite-Volume and Discontinuous Galerkin Methods Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 102 KB |
| Title: | Near-to-Far Field Transformation in FDTD: A Comparative Study of Different Interpolation Approaches |
| Abstract: | Equivalence theorems in electromagnetic field theory stipulate that farfield radiation pattern/scattering profile of a source/scatterer can be evaluated from fictitious electric and magnetic surface currents on an equivalent imaginary surface enclosing the source/scatterer. These surface currents are in turn calculated from tangential (to the equivalent surface) magnetic and electric fields, respectively. However, due to the staggered-in-space placement of electric and magnetic fields in FDTD Yee cell, selection of a single equivalent surface harboring both tangential electric and magnetic fields is not feasible. The work-around is to select a closed surface with tangential electric (or magnetic) fields and interpolate the neighboring magnetic (or electric) fields to bring approximate magnetic (or electric) fields onto the same surface. Interpolation schemes available in the literature include averaging, geometric mean and the mixed-surface approach. In this work, we compare FDTD farfield scattering profiles of a dielectric cube calculated from surface currents that are obtained using various interpolation techniques. The results are benchmarked with those obtained from integral equation solvers available in the commercial packages FEKO and HFSS. |
| Author(s): | R. C. Bollimuntha, M. F. Hadi, M. J. Piket-May, A. Z. Elsherbeni |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 5 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1425 KB |
| Title: | Multiresolution Time Domain Based Different Wavelet Basis Studies of Scattering of Planar Stratified Medium and Rectangular Dielectric Cylinder |
| Abstract: | In this paper, several wavelet bases, namely, the Daubechies, the biorthogonal Coiflet, the Deslauriers-Dubuc interpolating functions, and the cubic spline Battle-Lemarie, are applied to the multiresolution time domain (MRTD) technique for planar stratified media and electromagnetic scattering. These MRTD schemes are studied via field expansions of the scaling functions in one-dimensional (1D) and two-dimensional (2D) cases. A rigorous treatment method for inhomogeneous media structures is given. We have focused here on the study of reflected and transmission coefficients for an electromagnetic wave propagation on a stratified slab media and the scattering width (SW) of a rectangular dielectric cylinder. The 1D propagation characteristics of single and periodical stratified media and the 2D scattering width of the MRTD schemes are compared with the results of the FDTD method. Finally, we describe the computational accuracy of the relative peaks and shifting position errors, via a comparison of the results of the MRTD scheme based on the different basis with those of the FDTD method. |
| Author(s): | Q. Cao, K. K. Tamma, Q. Cao, K. K. Tamma |
| File Type: | Journal Paper |
| Issue: | Volume: 20 Number: 1 Year: 2005 |
| Download Link: | Click here to download PDF File Size: 639 KB |
| Title: | Microwave Tomography for Breast Cancer Detection Using Level Sets |
| File Type: | Conference Paper |
| Issue: | Volume: Imaging, Computation and Inverse Methods in Biomedicine Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 82 KB |
| Title: | Local Time Stepping Discontinuous Galerkin Time Domain Method for Solving Maxwell Equations |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Conformal Time-Domain Methods: Finite-Volume and Discontinuous Galerkin Methods Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 112 KB |
| Title: | Left-Handed Metamaterial Lens Applicator with Built-in Cooling Feature for Superficial Tumor Hyperthermia |
| Abstract: | In all hyperthermia schemes with lefthanded metamaterial (LHM) lens applicator, water bolus are used to prevent skin from being overheated during the hyperthermia treatment. Owing to water’s high refraction index, high reflection usually occurs at the interface between low-index LHM lens and water bolus, and between water and skin, which will lead to the low efficiency of hyperthermia. In this paper, we propose a new LHM lens applicator with built-in cooling feature for superficial tumor hyperthermia. Both simulation and experiment demonstrated that microwave hyperthermia with the proposed applicator may concentrate more microwave energy into deeper tissue if compared to hyperthermia with normal LHM lens. |
| Author(s): | Y. Tao, E. Yang, G. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 32 Number: 11 Year: 2017 |
| Download Link: | Click here to download PDF File Size: 1726 KB |
| Title: | Hybrid Integration Scheme for the Evaluation of Strongly Singular Integral over Curvilinear Triangle Surface |
| File Type: | Conference Paper |
| Issue: | Volume: S03 Advances in Curved Patch Modeling Number: Year: 2019 |
| Download Link: | Login To Download (For Members) File Size: 278 KB |
| Title: | Higher-Order Finite Difference Frequency Domain Methods for Electromagnetic Problems |
| File Type: | Conference Paper |
| Issue: | Volume: Finite Difference Methods Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 674 KB |
| Title: | High-Order FVTD on Unstructured Grids using an Object-Oriented Computational Engine |
| Abstract: | An object-oriented implementation of a finite-volume time-domain (FVTD) engine for solving Maxwell’s equations is presented. The relevant aspects of the FVTD method are discussed from an objectoriented perspective and details of the object classes are given. Computational results obtained using the FVTD engine for solving Maxwell’s Equations on unstructured grids are also shown. The engine implements both MUSCL and polynomial interpolation methods to approximate the fluxes at the cell boundaries up to thirdorder accuracy. In addition, the engine has the capability of using a number of time-integration schemes. Results are presented for the transient scattering from a PEC sphere and a lossy dielectric cube. For the case of the sphere, almost perfect agreement with the analytic solution in the time-domain is achieved. The number of cells required as compared to FDTD is substantially reduced. |
| Author(s): | Dmitry Firsov, Joe LoVetri, Ian Jeffrey, Vladimir Okhmatovski, Colin Gilmore Walid Chamma, Dmitry Firsov, Joe LoVetri, Ian Jeffrey, Vladimir Okhmatovski, Colin Gilmore Walid Chamma |
| File Type: | Journal Paper |
| Issue: | Volume: 22 Number: 1 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 555 KB |
| Title: | High-order FDTD methods via derivative matching for electromagnetic computation involving material interfaces |
| File Type: | Conference Paper |
| Issue: | Volume: Advances in Finite-Difference Time Domain Modeling Number: Year: 2004 |
| Download Link: | Login To Download (For Members) File Size: 156 KB |
| Title: | High-order Accurate Schemes for Maxwell-Bloch Equations with Material Interfaces |
| File Type: | Conference Paper |
| Issue: | Volume: S35 Advanced Time-Domain Numerical Methods For Nonlinear and Quantum Optics with Engineered Materials - II Number: Year: 2021 |
| Download Link: | Login To Download (For Members) File Size: 294 KB |
| Title: | High Order On Surface Radiation Boundary Conditions For Radar Cross-Section Application |
| Abstract: | Solving problems governed by two and threedimensional wave equations in exterior domains are a complex task. There are techniques to reduce the computational complexities, one such technique is On-Surface Radiation Boundary Conditions (OSRBC). There have been recent interests in revisiting this technique for two and three-dimensional problems [1]. In this paper, we explore the implementation of a new high order OSRBC based on the high order local boundary conditions introduced by [2] for two and three dimensions to solve the wave equation in unbounded domains. In most cases, it is difficult to construct exact solutions. For comparisons of numerical solutions, we use solutions obtained from large domains as approximate exact solutions. The implementation involves a two step novel approach to handle time derivatives. First, the governing equations and boundary conditions are converted to Laplace transform domain. Then, based on bilinear transformation the procedure was converted to z domain which simplified the implementation process. In particular, this process leads to higher accuracy compared to the different types of finite difference schemes used to approximate the first and second order partial derivative in the new high order OSRBC and the auxiliary functions that define the high order boundary conditions. A series of numerical tests demonstrate the accuracy and efficiency of the new high order OSRBC for two and three-dimensional problems. Both the long domain solutions as well as the new OSRBC solutions are compared for accuracies and useful results for radar cross-section calculations are presented. |
| Author(s): | A. Al Weshah, S. I. Hariharan |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 1 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1315 KB |
| Title: | Fourth-Order Accurate FDFD Method for General Waveguide Structures |
| File Type: | Conference Paper |
| Issue: | Volume: Finite Difference Methods: Recent Developments and Applications Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 322 KB |
| Title: | Fourier-Continuation Based Discontinuous Galerkin Time Domain Schemes for Electromagnetic Waves |
| File Type: | Conference Paper |
| Issue: | Volume: S13 Advanced Time Domain Solvers and Truncation Techniques for Multiphysics Modeling in Photonics Number: Year: 2020 |
| Download Link: | Login To Download (For Members) File Size: 2527 KB |
| Title: | Fast Parameter Scanning Method for Printed Circuits Based on Matrix High-Dimensional Interpolation |
| File Type: | Conference Paper |
| Issue: | Volume: 1-P1-B Integral Methods, Time-Domain and Frequency-Domain Computational Methods Number: Year: 2017 |
| Download Link: | Login To Download (For Members) File Size: 207 KB |
| Title: | Enhancement of Multifrequency Microwave Tomography Breast Imaging System using Flexible Preconditioner Based Krylov Subspace Methods |
| Abstract: | Microwave Tomography Imaging System (MwTIS) is an emerging tool for medical diagnosis in the non-invasive screening process. This paper addresses the ill-condition problem by proposing two new schemes incorporated into the DBIM image reconstructed algorithm for high frequencies in MwTIS. The first scheme is to propose an optimal step frequency using the degree of ill-posedness value for reducing the frequency diversity problem. The second scheme is to propose Krylov Subspace-based regularization method called Flexible Preconditioned Conjugate Gradient Least Square (FPCGLS) method to resolve the ill-condition problem. The iteratively updated preconditioner matrix in the proposed FP-CGLS method reduces the number of iterations and it is stable in high-level Gaussian noise. The efficiency of the proposed FP-CGLS method is validated by imposing Gaussian noise up to 30% in scattered breast phantom in the multifrequency range of 2 GHz -3 GHz It achieves an enhanced reconstructed image at 12 iterations with a relative error of 0.1802 for 20% of Gaussian noise and for the same scheme the existing CGLS method has a 0.4480 relative error at the 77 iterations. Further, the FP-CGLS along with the DBIM method produces a reconstructed image with the accuracy of 0.8760 in four DBIM iterations. |
| Author(s): | N. Nithya, M. S. K. Manikandan |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 6 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 1312 KB |
| Title: | Enhanced FDTD Schemes Based on Dispersion-Optimized Stencil-Adjustable Nonstandard Operators |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced FVTD/DG/FDTD Techniques Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 177 KB |
| Title: | Efficient Upwind Schemes for Linear and Nonlinear Dispersive Maxwell’s Equations on Overset Grids |
| File Type: | Conference Paper |
| Issue: | Volume: S33 Advanced Modeling of Disordered and Topological Systems - I Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 570 KB |
| Title: | Efficient Stochastic FDTD Algorithm with Optimized GPU Acceleration |
| Abstract: | A 3-D curvilinear stochastic finite-difference time-domain (S-FDTD) technique on modern graphics processing units (GPUs) is introduced in this paper for complex media with high levels of statistically-variable heterogeneities. The novel accelerated methodology develops a robust covariant/contravariant dual-grid tessellation and estimates the mean value and standard deviation of field components during only a single run. In this way, notably accurate and stable estimations can be very rapidly and economically obtained, unlike the usual multiple-realization staircase Monte-Carlo FDTD schemes. These merits are successfully verified via realistic microwave setups with highly-varying media uncertainties, where the featured algorithm is shown to overwhelm the typical exceedingly resource consuming approaches. |
| Author(s): | A. N. Papadimopoulos, G. G. Pyrialakos, N. V. Kantartzis, T. D. Tsiboukis |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 8 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1946 KB |
| Title: | Efficient High-Spatial-Order FDTD Analysis of 3D Optical Ring Resonator Filters |
| File Type: | Conference Paper |
| Issue: | Volume: Time Domain Numerical Modeling Beyond FDTD Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 153 KB |
| Title: | Domain Decomposition Scheme in Newmark-Beta-FDTD for Dispersive Grating Calculation |
| Abstract: | In this work, an efficient domain decomposition scheme is introduced into the unconditionally stable finite-difference time-domain (FDTD) method based on the Newmark-Beta algorithm. The entire computational domain is decomposed into several subdomains, and thus the large sparse matrix equation produced by the implicit FDTD method can be divided into some independent small ones, resulting in a fast speed lower-upper decomposition and backward substitution. The domain decomposition scheme with different subdomain schemes and different subdomain numbers is studied. With a generalized auxiliary differential equation (ADE) technique, the extraordinary optical transmission through a periodic metallic grating with bumps and cuts is investigated with the domain decomposition Newmark-Beta-FDTD. Compared with the traditional ADE-FDTD method and the ADENewmark- Beta-FDTD method, the results from the proposed method show its accuracy and efficiency. |
| Author(s): | S.-B. Shi, W. Shao, K. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 7 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1774 KB |
| Title: | Distributed-Memory Parallelization of an Explicit Time-Domain Volume Integral Equation Solver on Blue Gene/P |
| Abstract: | Two distributed-memory schemes for efficiently parallelizing the explicit marching-onin- time based solution of the time domain volume integral equation on the IBM Blue Gene/P platform are presented. In the first scheme, each processor stores the time history of all source fields and only the computationally dominant step of the tested field computations is distributed among processors. This scheme requires all-to-all global communications to update the time history of the source fields from the tested fields. In the second scheme, the source fields as well as all steps of the tested field computations are distributed among processors. This scheme requires sequential global communications to update the time history of the distributed source fields from the tested fields. Numerical results demonstrate that both schemes scale well on the IBM Blue Gene/P platform and the memoryefficient second scheme allows for the characterization of transient wave interactions on composite structures discretized using three million spatial elements without an acceleration algorithm. |
| Author(s): | A. Al-Jarro, M. Cheeseman, H. Bagci |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 2 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 961 KB |
| Title: | Discontinuous Galerkin - High order FDTD Hybridization for Scattering Problems |
| File Type: | Conference Paper |
| Issue: | Volume: S49 Hybrid and Multi-Physics II Number: Year: 2016 |
| Download Link: | Login To Download (For Members) File Size: 620 KB |
| Title: | DGTD Method Incorporating a Universal Dispersion Model for Nanoarchitectures |
| File Type: | Conference Paper |
| Issue: | Volume: 11-WA-5 Microwave and Antenna Technology for Wireless Body-Centric Systems Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 93 KB |
| Title: | Design Concepts for Broadband Antenna Arrays with Constant Half-Power Beamwidth |
| File Type: | Conference Paper |
| Issue: | Volume: S61 Antenna Arrays Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 759 KB |
| Title: | Compatible Discrete Operators scheme applied to Maxwell’s Equation in and its link with FDTD |
| File Type: | Conference Paper |
| Issue: | Volume: S43 Hybrid Electromagnetic Simulations Number: Year: 2023 |
| Download Link: | Login To Download (For Members) File Size: 421 KB |
| Title: | Comparison between two a posteriori error indicators for adaptive microwave FE analysis |
| File Type: | Conference Paper |
| Issue: | Volume: Finite Element Method and Applications Number: Year: 2003 |
| Download Link: | Login To Download (For Members) File Size: 502 KB |
| Title: | Compact Dual-band (28/38 GHz) Patch for MIMO Antenna System of Polarization Diversity |
| Abstract: | In this work a novel design of a compact-size patch antenna is introduced for dual-band operation at 28/38 GHz. The antenna is constructed as a perforated resonant patch on a defected ground structure (DGS). The development stages of the design are described in detail. The patch is inset-fed through a microstrip line. A four-port MIMO antenna system is constructed using the proposed patch antenna. The antennas are arranged at the corners of a mobile handset in orthogonal orientations which results in polarizations and spatial diversities as well as low mutual coupling. The single antenna as well as the MIMO antenna system performance is assessed through numerical simulations and experimental measurements. The scattering parameters including the reflection and coupling coefficients are calculated using the commercially available CST® package and measured experimentally showing good agreement. The proposed antenna has a bandwidth of 0.6 GHz at 28 GHz and 1.17 GHz at 38 GHz. To evaluate the performance of the proposed MIMO antenna system, key performance parameters such as the radiation efficiency, envelope correlation coefficient (ECC), and diversity gain (DG) are investigated. The proposed four-port MIMO antenna system configuration is shown to be suitable for polarization and spatial diversity schemes as illustrated from the resulting radiation patterns. The proposed antenna has high radiation efficiency and the MIMO system has very good values for the ECC and DG over the operating frequency bands. The MIMO system possesses good polarization and spatial diversities with good isolation between the antennas without the use of any isolation enhancement techniques. |
| Author(s): | M. A. El-Hassan, K. F. A. Hussein, A. E. Farahat |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 6 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 4698 KB |
| Title: | Benchmarking-based Approach to Engineering Stray-field Loss Problems |
| File Type: | Conference Paper |
| Issue: | Volume: Low Frequency Applications - 1 Number: Year: 2006 |
| Download Link: | Login To Download (For Members) File Size: 177 KB |
| Title: | Bandwidth Control of Optimized FDTD Schemes |
| Abstract: | We investigate the potential of controlling the wideband behavior of finite-difference time-domain (FDTD) methods, which adopt extended spatial operators while maintaining the standard temporal updating procedure. Specifically, single-frequency optimization is performed first, while wider bands are then treated with the aid of the least-squares technique. The proposed methodology is applied to various discretization schemes with different stencil sizes and shapes, thus verifying its versatile character. Theoretical as well as numerical results are presented, which demonstrate that the optimization process has a beneficial impact on the efficiency of FDTD algorithms, and yields attractive alternatives for reliable multi-frequency simulations. |
| Author(s): | T. T. Zygiridis |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 413 KB |
| Title: | Bandwidth Control of Optimized FDTD Schemes |
| File Type: | Conference Paper |
| Issue: | Volume: Advanced FVTD/DG/FDTD Techniques Number: Year: 2010 |
| Download Link: | Login To Download (For Members) File Size: 207 KB |
| Title: | Application of Evolutionary Optimization Algorithms in Computational Optics |
| Abstract: | The spatial and spectral treatment of electromagnetic fields express an essential operation regarding, e.g., the functionality of dense integrated opitcal devices. Such molding of fields can handly be handled without sophisticated heuristic optimization tools. By means of five design examples we have demonstrated that evolutionary algorithms (EA) are highly qualified to solve "real world" inverse problems considering various applications in the field of planar integrated optics, optical communication technology, and dielectric material modeling as well. In comparison to other optimization schemes Eas are even able to deliver structural and temporal information of the device under optimization which is an important feature when targeting computer guided engineering and virtual design platforms. |
| Author(s): | Dianel Erni, Dorthea Wiesmann, Michael Spuhler, Stephan Hunziker, Esteban Moreno, Dianel Erni, Dorthea Wiesmann, Michael Spuhler, Stephan Hunziker, Esteban Moreno |
| File Type: | Journal Paper |
| Issue: | Volume: 15 Number: 2 Year: 2000 |
| Download Link: | Click here to download PDF File Size: 15956 KB |
| Title: | Analysis of a scalable, parallel, 2D MLFMA solver |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Advances in Integral Equations and Fast Methods Number: Year: 2010 |
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| Title: | An Overview of Non-Overlapping and Fully Overlapping Domain Decomposition Methods |
| File Type: | Conference Paper |
| Issue: | Volume: In Tribute To Dr. Zoltan Cendes Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 532 KB |
| Title: | An Object Oriented Finite-Volume Time-Domain Computational Engine |
| File Type: | Conference Paper |
| Issue: | Volume: Object Oriented Computational Electromagnetics Number: Year: 2006 |
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| Title: | An Iterative CN-Leapfrog Scheme Based Hybrid Implicit–Explicit Discontinuous Galerkin Finite-Element Time-Domain Method for Analysis of Multiscale Problems |
| Abstract: | The discontinuous Galerkin finite-element time-domain (DG-FETD) method with the ability to deal with unstructured meshes is well suited to analyze the multiscale system. However the DG-FETD method with explicit integration schemes is constrained by stability conditions that can be very restrictive upon highly fine meshes. The hybrid implicit–explicit Crank- Nicolson (CN) leapfrog scheme is effective in solving this problem; but because of using CN scheme, the inversion of a large sparse matrix must be calculated at each time step in the fine regions. The hybrid implicit– explicit iterative CN leapfrog scheme is introduced to improve the computational efficiency which can form a block diagonal matrix. The leapfrog scheme is employed for electrically coarse regions and iterative CN scheme for electrically fine ones. The numerical examples have demonstrated the validity and efficiency of the method. |
| Author(s): | M. Li, X. D. Ye, F. Xu, Y. T. Yang |
| File Type: | Journal Paper |
| Issue: | Volume: 33 Number: 6 Year: 2018 |
| Download Link: | Click here to download PDF File Size: 1699 KB |
| Title: | An Empirical Study of the E ects of Flux Reconstruction on the FVFD Solution of Maxwell\'s Equations on Unstructured Grids |
| File Type: | Conference Paper |
| Issue: | Volume: Unstructured Mesh Time Domain Techniques Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 239 KB |
| Title: | An Effective Sparse Approximate Inverse Preconditioner for the MLFMA Solution of the Volume-Surface Integral Equation |
| Abstract: | In the framework of the multilevel fast multipole algorithm (MLFMA), effective construction of the sparse approximate inverse preconditioner (SAIP) for the volume-surface integral equation (VSIE) is discussed. A high quality SAIP for the entire VSIE matrix is constructed by using the sub-matrix of the nearfield interactions between the surface basis and testing functions arising from the surface integral equation alone. In addition, a simple sparse pattern selection scheme based on the geometrical information of nearby basis functions and octree regrouping strategy is proposed to enhance the efficiency of the SAIP. In contrast to the existing sparse pattern selection schemes, the proposed scheme utilizes the near-field matrix in the MLFMA more effectively with only one tuning parameter. Numerical results indicate that with the proposed scheme, both the memory usage and setup time for constructing an effective SAIP are significantly reduced without compromising the efficiency and robustness. |
| Author(s): | J. Liu, Z. Li, M. He, J. Su |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 8 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1681 KB |
| Title: | An Adaptive Basis Function Solution to the 1D and 2D Inverse Scattering Problems using the DBIM and the BIM |
| Abstract: | We present the use of an adaptive set of basis functions used in conjunction with the MoM to solve the linearized scalar inverse electromagnetic scattering problem. The basis functions, which are whole-domain and harmonic, are selected to provide a perfectly conditioned solution under the first-order Born approximation when multiple frequency experiments are considered. In order to iteratively solve the full nonlinear problem by the Distorted Born Iterative Method (DBIM) and/or the Born Iterative Method (BIM), we introduce a single parameter into the basis function expansion to demonstrate that it is possible to maintain a well-conditioned linearized inverse problem by selecting the parameter value that minimizes the condition number of the discrete matrix operator. The proposed technique eliminates the need for Tikhonov regularization or equivalent regularization schemes commonly applied to the single-frequency, pulse-basis formulation of the linearized inverse scattering problem. |
| Author(s): | Ian Jeffrey, Vladimir I. Okhmatovski, Joe LoVetri, Colin Gilmore, Ian Jeffrey, Vladimir I. Okhmatovski, Joe LoVetri, Colin Gilmore |
| File Type: | Journal Paper |
| Issue: | Volume: 22 Number: 1 Year: 2007 |
| Download Link: | Click here to download PDF File Size: 619 KB |
| Title: | Alamouti and Differential Transmit Diversity for Air-to-Ground Communications |
| File Type: | Conference Paper |
| Issue: | Volume: MIMO and Diversity System Characterization Number: Year: 2005 |
| Download Link: | Login To Download (For Members) File Size: 134 KB |
| Title: | Advanced Modeling and Simulation for Test and Evaluation of Electromagnetic Threat Assessment |
| File Type: | Conference Paper |
| Issue: | Volume: New Electromagnetic Techniques and Measurements Number: Year: 2011 |
| Download Link: | Login To Download (For Members) File Size: 498 KB |
| Title: | Adaptable Nonstandard FDTD Schemes for the Precise Evaluation of Electrostatic Fields |
| File Type: | Conference Paper |
| Issue: | Volume: S08 Advances in Finite Difference and Other Numerical Methods for Computational Electromagnetics and Photonics Number: Year: 2020 |
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| Title: | Adaptable Nonstandard FDTD Schemes for the Precise Evaluation of Electrostatic Fields |
| Abstract: | The reduction of the total computational overhead in the design of complex geometries, such as modern aircrafts, is a very challenging problem, particularly when electrostatic fields (ESF) for lightning protection, are considered. To this aim, an efficient ESF evaluation scheme, based on the nonstandard finite-difference time-domain (NS-FDTD) method, is proposed. Combining the total-field/scattered-field (TF/SF) concept with a distinct sine-wave form, the novel technique cancels the accumulative errors caused by the static field component. Numerical results reveal that the featured method enables the use of high-frequency discretization models to ESF problems, with notable accuracy and seriously decreased design costs. |
| Author(s): | T. Ohtani, Y. Kanai, N. V. Kantartzis |
| File Type: | Journal Paper |
| Issue: | Volume: 35 Number: 11 Year: 2020 |
| Download Link: | Click here to download PDF File Size: 1410 KB |
| Title: | Accurate 3D Characterization and Synthesis of Real Antenna Arrays via Support Vector Regression |
| File Type: | Conference Paper |
| Issue: | Volume: Analysis and Design of Antennas for Wireless Communications Number: Year: 2007 |
| Download Link: | Login To Download (For Members) File Size: 1211 KB |
| Title: | ACCURACY OF THREE UNCONDITIONALLY-STABLE FDTD SCHEMES |
| Abstract: | This paper discusses accuracy limitations due to numerical dispersion and time step size for three implicit unconditionally-stable FDTD methods: Alternate-Direction-Implicit (ADI), Crank-Nicolson (CN) and Crank-Nicolson-Douglas-Gunn (CNDG). It is shown that for a uniform mesh, the three methods have the same numerical phase velocity along the axes, but have large differences along the diagonals. The ADI method has two orders-of-magnitude larger anisotropy than that of CN and CNDG. CNDG has no anisotropy at certain Courant numbers and mesh densities. At the limit of zero spatial mesh size, the three methods have different “intrinsic temporal dispersion” for a given time step size: CN has no anisotropy; ADI has positive anisotropy and CNDG has negative anisotropy, which is much smaller than ADI. The Nyquist sampling theorem provides a fundamental upper bound on the time step size for all three methods. It is shown that for ADI and CN the practical upper bound is close to the Nyquist limit, but for CNDG is half the Nyquist limit. |
| Author(s): | G. Sun, C. W. Trueman, G. Sun, C. W. Trueman |
| File Type: | Journal Paper |
| Issue: | Volume: 18 Number: 3 Year: 2003 |
| Download Link: | Click here to download PDF File Size: 136 KB |
| Title: | A Topological Charge Continuously Tunable Orbital Angular Momentum (OAM) Electromagnetic Wave Generation Method Based on Fixed-length Delay Line Mixing Circuit |
| Abstract: | To overcome the drawback of complex structure and high cost attributed from the utilization of phase shifters to generate OAM in the conventional schemes, this paper proposes a new method for generating OAM based on a fixed delay line. By deriving the proposed system with fixed delay line theoretically, the relationship between the frequency of the input signal on the delay line and the topological charge of the OAM is obtained, and the topological charge of the generated OAM can be controlled by controlling the frequency. Furthermore, this paper proposes a vortex beam pointing control method based on phased array scanning, so as to realize the beam steering of OAM. It is then verified by using electromagnetic simulation, and the simulation results show that the proposed method is feasible. The proposed method not only has the advantages of simple structure and low cost, but also can generate OAM with continuously adjustable topological charge by controlling the frequency, which has the functions of topological charge reconstruction and dynamic adjustment. |
| Author(s): | Y. Zhou, X. Li, K. Yao, Y. M. Huang, H. Jin |
| File Type: | Journal Paper |
| Issue: | Volume: 37 Number: 10 Year: 2022 |
| Download Link: | Click here to download PDF File Size: 1349 KB |
| Title: | A Three Dimensional FDTD Algorithm for Wave Propagation in Cold Plasma Media using Forth-Order Schemes |
| Abstract: | A fourth-order accurate in space and second-order accurate in time, finite-difference time-domain (FDTD) scheme for wave propagation in cold plasma media is presented. The formulation of Maxwell’s equations is fully described and an elaborate study of the stability and dispersion properties of the resulting algorithm is conducted. The efficiency of the proposed FDTD (2, 4) technique in cold plasma media compared to its conventional FDTD (2, 2) counterpart is demonstrated through numerical results. |
| Author(s): | M. Pourbagher, S. Sohafi |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 12 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 493 KB |
| Title: | A Stable Higher Order Time Domain Electric Field Integral Equation Solver |
| File Type: | Conference Paper |
| Issue: | Volume: Student Paper Competition Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 5859 KB |
| Title: | A Stable Higher Order Time Domain Electric Field Integral Equation Solver |
| File Type: | Conference Paper |
| Issue: | Volume: Time Domain Methods in CEM Number: Year: 2012 |
| Download Link: | Login To Download (For Members) File Size: 5859 KB |
| Title: | A Preconditioning Strategy for the Mortar Element Electric Field Integral Equation |
| File Type: | Conference Paper |
| Issue: | Volume: Parallel Implementations for Solving Electromagnetics Problems Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 175 KB |
| Title: | A Novel Enhancing Technique for Parallel FDTD Method using Processor Affinity and NUMA Policy |
| Abstract: | The traditional multiple CPUs mounted on one node in a high performance cluster is based on Symmetric Multi-Processing (SMP) architecture. The memory bandwidth is a major bottleneck in the high performance computing. Recently, Intel and AMD companies developed the (Non-uniform Memory Access (NUMA) architecture for the multi-CPU server that is an important extension of the SMP computer. In the NUMA architecture server, each CPU has its own memory and can also be access to the memory located the nearby of other CPUs through the onboard network. For a parallel code, we can allocate the data for each CPU inside its local memory to accelerate the memory access. In this paper, we investigate a way how to achieve the high performance of parallel FDTD code on a computer cluster that includes 21 nodes with 42 CPU and 168 cores. Numerical experiments have demonstrated that different job binding schemes can significantly affect the performance of parallel FDTD code. |
| Author(s): | L. Zhao, G. Chen, W. Yu |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 8 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 1429 KB |
| Title: | A Novel 3D Pseudo-spectral Analysis of Photonic Crystal Slabs |
| Abstract: | Abstract—We consider a double-periodic slab which is characterized by two lattice vectors a1 and a2 on the (x;y)¡plane, the thickness hz and a three-dimensional scalar function e(x;y; z) specifying the dielectric constitution of the slab. Above and below the slab is free space. These assumptions imply that the z¡direction is special in this problem. Therefore, following a general scheme we diagonalize the Maxwell’s equations with respect to this direction. The periodicity in two directions suggests the use of spatially harmonic functions as a basis. We exploit this property; however, contrary to the traditional schemes, we propose an expansion of the fields in the form Y(r; z) = ån fn(z)exp( jkn ¢ r) allowing fn(z) to be a fairly general function of the z-coordinate, rather than an exponential function. In this expression r is the position vector in the (x;y¡) transversal plane. To guarantee maximum flexibility we discretize f in terms of finite differences. We demonstrate the superiority of our method by discussing the following properties: i) Diagonalization only involves the transversal field components, ii) Diagonalization allows us easily to construct and implement various boundary conditions at the bounding surfaces z = 0 and z = hz, iii) The resulting discretized system is extraordinarily stable and robust, and facilitates fast computations; from the computational performance point of view it compares well with existing methods, while it by far applies to larger class of problems, iv) It allows to use both the radian frequency w and the wavevector K as input parameters. Therefore, the resulting discrete system can be solved at individual (w;K)-points of interest, v) Finally, the method is applicable to both the eigenstate end the excitation problems. |
| Author(s): | K. Varis, A. R. Baghai-Wadji, K. Varis, A. R. Baghai-Wadji |
| File Type: | Journal Paper |
| Issue: | Volume: 19 Number: 1 Year: 2004 |
| Download Link: | Click here to download PDF File Size: 1103 KB |
| Title: | A New Electrode Configuration Scheme in Electrical Impedance Tomography for Thorax Imaging |
| File Type: | Conference Paper |
| Issue: | Volume: 6-ME-5 Inverse Scattering - Theory, Methods and Applications II Number: Year: 2018 |
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| Title: | A Method to Reduce the Back Radiation of the Folded PIFA Antenna with Finite Ground |
| Abstract: | A novel method, named the resistors and inductors loading, is proposed in this paper to reduce the back radiation of the folded PIFA antenna with finite ground. With different loading schemes (i.e., resistors loading, inductors loading, and resistors and inductors loading), variable reduced back radiation and gain can be achieved. However, there is a compromise between the gain and back radiation and it can be chosen based on the specified applications. A prototype with resistors loading is fabricated and measured to verify the proposed design. Measured results agree well with the simulated results. |
| Author(s): | Y. Li, P. Yang, F. Yang, S. He |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 2 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 747 KB |
| Title: | A High-Order Accurate FDTD Scheme for Maxwell’s Equations on Overset Grids |
| File Type: | Conference Paper |
| Issue: | Volume: S43 Computational Nanophotonics: Advanced Numerical Methods and Applications I Number: Year: 2018 |
| Download Link: | Login To Download (For Members) File Size: 664 KB |
| Title: | A Generic Framework for the Parallel MLFMA |
| File Type: | Conference Paper |
| Issue: | Volume: Parallel Implementations for Solving Electromagnetics Problems Number: Year: 2013 |
| Download Link: | Login To Download (For Members) File Size: 380 KB |
| Title: | A Comprehensive Study of SS-TLM Numerical Dispersion – Comparison with ADI-FDTD |
| File Type: | Conference Paper |
| Issue: | Volume: Recent Developments and Applications with Time-domain Modeling Techniques Number: Year: 2008 |
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