ACES Publication Search
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| Title: | ACES Journal June 2015 Cover |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 2346 KB |
| Title: | ACES Journal June 2015 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 30 KB |
| Title: | ACES Journal June 2015 Full |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 18253 KB |
| Title: | Design and Evaluation of the Multilevel Mesh Generation Mode for Computational Electromagnetics |
| Abstract: | This work presents a multilevel technique developed for speeding-up efficiently the mesh generation process of large and complex bodies for electromagnetic analysis. The targets are meshed by generating intermediate meshes with elements of decreasing size edge until the desired size is reached. The technique minimizes the time of meshing any given geometry and ensures a high quality mesh, as the input geometry at any level is composed of simple surfaces that can be meshed easily. The times of meshing on several geometries with and without the proposed method are compared as well as the quality statistics of the meshes obtained. The Method-of-Moments is used to evaluate the accuracy of the resulting meshes. |
| Author(s): | J. Moreno, M. J. Algar, I. Gonzalez, F. Catedra |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1003 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: | 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: | Fast and Accurate Electric Field Estimation from a Single Ray Tracing Simulation |
| Abstract: | In this work, an efficient field estimation technique is developed. This technique uses a single simulation of a ray tracing tool, at one spatial point at one frequency, to compute the field in the vicinity of the simulated point throughout a complete frequency range. The developed technique is a two-step procedure. Firstly, it operates over the images and field contributions generated by the ray tracing tool at the simulated receiver point to obtain an appropriate set of field contributions for each new receiver point. Secondly, once the new set of images and contributions at one frequency is obtained, a very simple extrapolation procedure is applied to obtain the electric field throughout a frequency range. The whole technique is computationally very efficient and it is also accurate, as the measurements comparison shows. |
| Author(s): | J. Pascual-Garcia, J.-M. Molina-Garcia-Pardo, M.-T. Martinez-Ingles, J.-V. Rodriguez, L. Juan-Llacer |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 2022 KB |
| Title: | Dual Band-Notched Small Monopole Antenna with Bandwidth Enhancement by Means of Defected Ground Structure (DGS) for UWB Application |
| Abstract: | In this study, a small and compact dual band-notched microstrip-fed printed monopole antenna for ultra-wideband applications has been presented. This antenna consists of a square patch as radiator and a defected ground structure (DGS). In order to generate dual band-notched function, we use four slots in the ground plane. A parametric study of the proposed antenna is provided to achieve the dual band-notched by adjusting the lengths of the rectangular-shaped slots. The proposed antenna can easily adjust its stop-band functions by half-wavelength. Mainly, desired stopbands are obtained without any variation on the patch. Using of this structure on the ground plane, the impedance bandwidth is effectively improved at the higher band, which results in a wide usable fractional bandwidth of more than 134% (2.7-13.7 GHz), defined by VSWR<2, with two notched bands, covering all the 5.2/5.8-GHz WLAN, 3.5/5.5-GHz WiMAX, and 4-GHz C-bands. The constructed antenna is small (15×15 mm2 ) when compared with previously proposed single- and double-filtering monopole antennas with DGS in terms of slots on the ground only. The antenna has a desirable voltage standing wave ratio (VSWR) level and acceptable antenna gain for ultrawideband frequency band range. |
| Author(s): | Z. Esmati, M. Moosazadeh |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1573 KB |
| Title: | Time-Reversal Through-Wall Microwave Imaging in Rich Scattering Environment Based on Target Initial Reflection Method |
| Abstract: | In recent years, time reversal (TR) methods have been widely employed in microwave imaging (MI) applications due to their efficient functionality in heterogeneous media. One of the applications turning into a great interest is through-wall microwave imaging (TWMI). In this paper, classic TR method is applied to detect and localize a target obscured by a brick wall inside a rich scattering environment using numerically generated data. Regarding this, it is shown when the signals acquired by a set of receivers are time reversed and backpropagated to the background media, finding an optimum time frame which the constituted image represents a true location of the target becomes infeasible. Indeed, based on target distance and increasing multiple scattering in the media the previously-used maximum E-field method and entropybased methods fail to select the optimum time frame. As a result, an improved procedure named target initial reflection method (TIRM) is proposed. Even in the case of rich scattering environment, the results show this method prevails over the incapabilities of the former methods. |
| Author(s): | A. B. Gorji, B. Zakeri |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1764 KB |
| Title: | Fast Orthogonal Propagator Direction-Finding Algorithm Based on Fourth-Order Cumulants |
| Abstract: | In this paper, a low complexity approach called modified fourth-order cumulants orthonormal propagator method (MFOC-OPM) is proposed for direction-of-arrival (DOA) estimation of incident narrowband signals impinging on a uniform linear array (ULA). In the proposed algorithm, the modified fourthorder cumulants (MFOC) matrix is achieved via removing the redundant information encompassed in the primary fourth-order cumulants (FOC) matrix, and then the direction-of-arrivals (DOAs) estimation of source signals can be resolved by exploiting the orthonormal propagator method (OPM). Without any spectrum-peak searching and eigenvalue decomposition (EVD) of the MFOC matrix, the theoretical analysis coupled with simulation results show that in comparison with the MFOC-MUSIC algorithm, the resultant algorithm can reduce computational complexity significantly, as well as yield good estimation performance in both spatiallywhite noise and spatially-color noise environments. |
| Author(s): | H. Shi, W. Leng, A. Wang, H. Chen, Y. Ji |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 738 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: | A Novel CRLH-CP Antenna with the Capability to be Integrated Inside RF Components for RF Electronic Devices and Embedded Systems |
| Abstract: | In this paper, design and manufacturing of a composite right/left-handed carved planar (CRLH-CP) antenna with ? ? constitutive parameters is introduced. The composite right/left-handed transmission line (CRLH-TL) is introduced as a general TL possessing both left-handed (LH) and righthanded (RH) natures. The proposed antenna is constructed of four CRLH unit cells, each of which occupies space of 0.004?0×0.01?0×0.001?0, where ?0 is free space wavelength at 0.5 GHz. The antenna practical bandwidth is 120%, so that the proposed antenna can be used for frequency band from 0.5 GHz to 2 GHz in measurement. Also, the antenna gains and radiation efficiencies at the operational frequencies f=0.7, 1.5 and 2 GHz are 3.8 dBi and 53%, 4.85 dBi and 68.5%, and 4.3 dBi and 60.2%, respectively. According to the results, the proposed minimized ultra wideband (UWB) antenna is a good candidate to use in the RF electronic devices and embedded systems. |
| Author(s): | M. Alibakhshi-Kenari, M. Naser-Moghaddasi |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1406 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: | A Three-Conductor Transmission Line Model for MOS Transistors |
| Abstract: | An accurate high frequency small signal model for MOS transistors is presented. In the proposed model, by considering the layout of the MOS transistor, it is considered as a three-conductor transmission line. Then, a set of current-voltage equations are derived for the structure using the transmission line theory. These coupled equations are solved by the Finite-Difference Time-Domain (FDTD) technique in a marching-in-time process. To verify the model, the scattering parameters of a 0.13 m transistor are extracted from the time domain results over the 1–100 GHz frequency band and compared with the results obtained from the available models and commercial simulator. The suggested model can be useful in design of various types of high frequency integrated circuits. |
| Author(s): | F. Daneshmandian, A. Abdipour, R. Mirzavand |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 763 KB |
| Title: | Hybrid Method Combining DGTD and TDIE for Wire Antenna-Dielectric Interaction |
| Abstract: | This paper presents a hybrid method that effectively combines two versatile numerical methods - the discontinuous Galerkin time domain (DGTD) method and the time domain integration method (TDIE). The hybrid method is highly applicable to coupling problems involving arbitrarily-shaped thin-wires and dielectric structures with inhomogeneous lossy materials. The original problem can be divided into two sub-regions which are analyzed using the DGTD and the TDIE methods, respectively, and their solutions are exchanged via the interface of the sub-regions by using Huygens’ equivalence principle. To improve the efficiency of the hybrid method, a revised Courant– Friedrichs–Lewy (CFL) factor for the DGTD method is proposed, which could effectively reduce computation time. To validate the hybrid method and the revised CFL factor, several numerical examples are presented, proving the proposed method a promising scheme. |
| Author(s): | S. P. Gao, Y. L. Lu, Q. S. Cao |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 488 KB |
| Title: | Band-Notched Small Slot Antenna Based on Time-Domain Reflectometry Modeling for UWB Applications |
| Abstract: | A design of a compact band-notched slot antenna by using defected structures with time domain designing method for UWB applications is presented. By cutting two modified meander line slots in the ground plane, a new resonance at the higher frequencies is excited, and hence, much wider impedance bandwidth can be produced that provides an ultra-wideband (UWB) frequency range. To generate a band-notched characteristic, we use the step-impedance resonator (SIR) slot at feed-line which contains a rectangular slot with a W-shaped strip protruded inside the slot. The proposed antenna can operate from 3.07 to 12.91 GHz with frequency band-notched function in 5.12-5.96 GHz to avoid interference from WLAN systems. To verify the validation of the proposed antenna, the equivalent circuit based on time domain reflectometry (TDR) analysis is presented. The proposed antenna exhibits almost omnidirectional radiation patterns in UWB frequency range. The designed antenna has a small size of 20×20 mm2 . |
| Author(s): | N. Mikaeilvand, M. Ojaroudi, N. Ghadimi |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 956 KB |
| Title: | Efficient FDTD Implementation of the ADE-Based CN-PML for the Two-Dimensional TMz Waves |
| Abstract: | An efficient, unsplit-field and unconditional stable implementation of the stretched coordinate perfectly matched layer (SC-PML) is proposed for terminating the finite-difference time-domain (FDTD) method. Via incorporating the Crank-Nicolson Douglas-Gunn (CNDG) and the auxiliary differential equation (ADE) methods, respectively, the proposed PML formulations can take advantage of the unconditional stability of the CNDG method which has smaller numerical anisotropy than the existing alternately direction implicit (ADI) method. A numerical test carried out in a 2D free space FDTD domain is provided to validate the proposed CNDGbased PML. It has been shown that the proposed PML can not only overcome the Courant-Friedrich-Levy (CFL) stability constraint, but attenuate the propagating waves efficiently. |
| Author(s): | J. Li, H. Jiang, N. Feng |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 354 KB |
| Title: | Miniaturized Microstrip Bandpass Filters Using Novel Stub Loaded Resonator |
| Abstract: | In this paper, a novel structure is proposed to design two compact microstrip bandpass filters operated at 2.39 GHz and 5.73 GHz, which their sizes are 44 mm2 and 14 mm2 , respectively. Miniaturization, resonance frequency tuning and harmonics attenuation methods are presented. Low insertion losses and wide fractional bandwidths are achieved. The obtained insertion losses and fractional bandwidths of the 2.39 GHz and 5.73 GHz filters are 0.27 dB, 0.19 dB, 46%, and 44%, respectively. Also for both filters, the second and third harmonics are attenuated. The proposed filters are fabricated and measured and there is a good agreement between the simulation and measurement results. |
| Author(s): | M. Salehi, L. Noori |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 6 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 692 KB |