ACES Publication Search
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| Title: | ACES Journal November 2016 Cover |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2119 KB |
| Title: | ACES Journal November 2016 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 97 KB |
| Title: | ACES Journal November 2016 Full |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 10847 KB |
| Title: | Approximate Calculation of the Total Attenuation Rate of Propagating Wave Inside Curved Tunnel |
| Abstract: | In this paper, a model is presented to simulate wave propagation in curved rectangular tunnels with imperfectly conducting walls. The model is based on treating the tunnel as a waveguide, which is an extension of previous proposed model by Mahmoud [3]. A new approach to calculate the total attenuation rate of the propagated wave inside tunnel is proposed. The approach is considering the effect of imperfect conductivity of the upper and lower walls of the tunnel. This approach is based on assuming that the boundaries of the tunnel section are constant impedance surfaces as the surface impedance of the wall is almost independent of the angle of the wave incidence onto the wall. A simple 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, A. M. Attiya, S. F. Mahmoud, M. El-Said, E. A. Hashish |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1763 KB |
| Title: | Efficient Electromagnetic Scattering Analysis of Open-ended Circular Cavities with Modal MoM Method |
| Abstract: | An efficient and accurate technique is introduced to calculate the scattered electromagnetic (EM) fields from an open-ended circular cavity (OECC). In this paper, it is assumed that the OECC is perforated in an infinite perfect electric conductor (IPEC). Then, the scattered fields are calculated using modal Method of Moments. The complexity and computational cost of the encountered quadruple integrals are addressed in detail. Here, the singularities are extracted and resolved. Next, the scattered far field of a circular PEC plate of the same size is calculated by physical optics approximation. The final OECC scattered field is the sum of these two solutions. A very good agreement is observed between the results of this method and full wave numerical simulations and measurements. The proposed approach is highly efficient and accurate over a wide range of frequencies and incidence angles, making it appealing for analysis of large frequency dispersive structures. |
| Author(s): | A. Aghabarati, P. Dehkhoda, A. Tavakoli |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2341 KB |
| Title: | Fast Monostatic Scattering Analysis Based on Bayesian Compressive Sensing |
| Abstract: | The Bayesian compressive sensing algorithm is utilized together with the method of moments to fast analyze the monostatic electromagnetic scattering problem. Different from the traditional compressive sensing based fast monostatic scattering analysis method which cannot determine the required measurement times, the proposed method adopts the Bayesian framework to recover the underlying signal. Error bars of the signal can be obtained in the recovery procedure, which provides a means to adaptively determine the number of compressive-sensing measurements. Numerical results are given to demonstrate the accuracy and effectiveness of proposed method. |
| Author(s): | H.-H. Zhang, X.-W. Zhao, Z.-C. Lin, W. E. I. Sha |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1900 KB |
| Title: | Moving Targets Imaging in Spaceborne TOPS SAR |
| Abstract: | Terrain Observation by Progressive Scans (TOPS) is the spaceborne wide swath synthetic aperture radar (SAR) imaging mode and attractive for ocean remote sensing. Its imaging processors are quite different from the one of the conventional stripmap mode due to antenna beam progressive scanning. This paper proposes a new imaging processor in TOPS for moving targets especially for moving ships in ocean. In addition to resolving the azimuth aliasing problem in TOPS, the Doppler parameter estimation is the key point of the proposed processor. According to the estimated Doppler parameters, some transfer functions of the processor should be updated. Simulation results on point and distributed targets validate the proposed imaging processor. |
| Author(s): | H. Mo, W. Xu, Z. Zeng |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1860 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: | 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: | Efficient Analysis of Object with Fine Structures by Combined MLSSM/MLFMA via Compressed Block Decomposition Preconditioner |
| Abstract: | A large dense fine mesh is used to model object with fine structures to guarantee good solution accuracy, and this in turn places an inordinately heavy burden on the CPU in terms of both memory requirement and computational complexity. To analyze the large dense complex linear system efficiently, the combined MLSSM/MLFMA is used to accelerate the matrix-vector multiplication. Multilevel fast multipole algorithm (MLFMA) cannot be used to analyze the box’s size of tree structure below 0.2 wavelength, because the “low frequency breakdown” phenomenon would happen. For the large-scale problems, the matrix assembly time of multilevel simply sparse method (MLSSM) is much longer than that of MLFMA. This combined method takes advantage of the virtues of both MLFMA and MLSSM, which is more efficient than either conventional MLFMA or conventional MLSSM. An efficient preconditioning technique based on compressed block decomposition (CBD) is applied to speed up the convergence rate. Numerical results are presented to demonstrate the accuracy and efficiency of the proposed method. |
| Author(s): | Z. N. Jiang, F. Shen, Y. Xu, X. Y. Yang |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1486 KB |
| Title: | Novel UWB Trapezoidal and Butterfly Shaped Microstrip Phase Shifters Using Multilayered PCB Technology |
| Abstract: | In this paper, design of two different aperture-coupled phase shifters for ultra-wideband (UWB) multilayer microwave circuits are introduced. The proposed phase shifters use broadside coupling between microstrip patches at the top and the bottom layers via a rectangular-shaped slot in the common ground plane (mid-layer). The proposed patch shapes are trapezoidal and butterfly shapes which are capable of achieving broadband characteristics for UWB operation. The reference transmission line is installed on the top layer. The numerical calculated results using two simulation programs using two different numerical techniques show that the proposed phase shifters have good phase characteristics with high return losses and good insertion losses over most of the 3.1–10.6 GHz frequency band. The phase characteristics for the proposed phase shifters can be easily controlled by proper adjusting the physical dimensions. Two 45° phase shifters prototypes are fabricated and then tested experimentally using Agilent E8364B PNA Network Analyzer. Experimental results are in good agreement with the calculated ones. |
| Author(s): | O. M. Haraz, A.-R. Sebak |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2185 KB |
| Title: | A Quadruple Band-Notched UWB Antenna by Using Arc-Shaped Slot and Rotated E-shaped Resonator |
| Abstract: | A simple quadruple band-notched ultra-wideband (UWB) antenna is proposed and its performance is investigated both numerically and experimentally. The proposed quadruple band-notched UWB antenna is realized based on an asymmetric planar monopole antenna which consists of a fan-shaped radiation patch, a microstrip feeding line and a trapezoidal ground plane. By etching an arc-shaped slot with a gap and adding a rotated E-shaped resonator beside the microstrip feeding line, four notched bands are achieved to suppress potential interferences from WiMAX (3.3-3.6 GHz), WLAN (5.15-5.35 GHz, 5.725-5.825 GHz) and uplink of X-band satellite communication system (7.9-8.4 GHz). The proposed monopole antenna can operate over 2.94-12 GHz band with VSWR<2 except these notch bands. Simulation and measurement results of the fabricated prototype demonstrate that the proposed antenna has quadruple band-notched characteristics and near-omnidirectional radiation patterns, making it suitable for UWB communication applications. |
| Author(s): | Y. Kong, Y. Li, W. Yu, K. Yu |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1721 KB |
| Title: | Ultra-Wideband Low Profile, U-Slot Microstrip Patch Antennas: L-Probe Feed Design Guidelines |
| Abstract: | The need for low-profile and ultra-wideband (UWB) antennas is rising in wireless communication and medical applications. The method of dimensional invariance, which is a class of U-slot patch design methods, is utilized to realize an initial, low-profile, wideband design. Building on this initial wideband design, this study establishes ideal L-probe feed dimensions through extensive parametric study on ?r = 2.2 and 4.5 substrates to propose empirical guidelines for the design of L-probe feeds which yield first-pass optimum impedance bandwidth. The established ideal L-probe dimensions, after further extrapolation, are used successfully on other substrates, ?r = 3.27, 6.0 and 9.2, for the design of first-pass L-probe feeds which yield impedance bandwidth over 55%, 60%, and 53%, respectively. The results of three commercially available EM simulation solvers show good agreement. |
| Author(s): | M. M. Elsewe, V. K. Dandu, D. Chatterjee |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2001 KB |
| Title: | Fully Distributed Analysis of MOS Transistor at Millimeter-Wave Band, Based on Matrix-Functions of the Three Line Active Transmission Lines Model |
| Abstract: | In this paper, distributed model of MOS transistor is presented that is based on active multi-conductor transmission line model. The analysis is done in frequency domain by considering frequency dependence of primary parameters such as series resistance caused by skin effect. The analysis is performed based on matrix function that is calculated by eigenvalue approach in the frequency domain. The scattering parameters are computed by using transmission matrix and applying boundary conditions. To investigate the analysis, the scattering parameters of a 0.13 ?m transistor are calculated by proposed approach over the 1–100 GHz frequency band. They compared with the results obtained from the available lumped and distributed models and a commercial simulator that have a good agreement with each other. |
| Author(s): | H. Khoshniyat, A. Abdipour, G. Moradi |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1688 KB |
| Title: | An Efficient Spectral Element Method for Semiconductor Transient Simulation |
| Abstract: | An efficient spectral element method (SEM) based on Gauss-Lobatto-Legendre (GLL) polynomials is proposed for the semiconductor transient simulation. The fully coupled Newton iteration method is employed to solve the nonlinear drift-diffusion model. The mixorder basis functions with different variables and domains are employed to give a full play to the superiority of the proposed SEM. The PIN diode with quasi onedimensional structure has been analyzed, and the numerical results have demonstrated the efficiency and accuracy of the proposed method. |
| Author(s): | H. Bao, D. Ding, J. Bi, W. Gu, R. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1639 KB |
| Title: | A Design of Low-pass Filter with Wide Stopband and Sharp Roll-off Rate Using Series LC Tanks Resonator |
| Abstract: | In this letter, a lowpass filter (LPF) using resonators synthesized with series LC tank patches has been proposed. Each of the employed LC tank is composed of a high-low impedance lines, which have been mirrored to create the patches of the main resonance cells. Using this kind of resonator combining with eight suppressing cells leads to designing a LPF with specifications such as ultra-wide stopband, sharp cut-off and an acceptable return loss in the pass band. The -3 dB cut-off frequency of the proposed LPF is located in 2.4 GHz. The spurious frequencies have been suppressed in the stop-band region from 2.66 up to 23 GHz with a suppression level of -35 dB. Moreover, the transition band has been measured from 2.4 to 2.67 GHz with corresponding attenuation levels of -3 and -40 dB, respectively. To clarify the performance of each section and how they affect the frequency response the equivalent LC circuit of resonators and the final design have been obtained, separately. |
| Author(s): | A. R. Nouritabar, As. Abdipour, Ar. Abdipour |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2129 KB |
| Title: | Loop-based Flux Formulation for Three-dimensional Magnetostatic Problems |
| Abstract: | In this paper, loop basis functions are introduced to expand the magnetic flux density and the magnetostatic subset of Maxwell’s equations are solved in a compact and straightforward manner using finite element method. As linear combinations of div-conforming Schaubert-Wilton-Glisson basis functions in three-dimensional, loop basis functions are inherently divergence-free and originally constructed to represent solenoidal electric current density in the electric field integral equation. Sharing the same physical property with the solenoidal electric current density, the magnetic flux density can also be represented by the loop basis functions and thus, Gauss’ law for magnetism is naturally satisfied; which is out of the capability of general Whitney elements. The relationship between the loop basis functions and Whitney elements, as well as the comparison between the proposed method and traditional method pertinent to magnetic vector potential are investigated. |
| Author(s): | Y.-L. Li, S. Sun, Z.-H. Ma |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1670 KB |
| Title: | Amplitude Only Linear Array Synthesis with Desired Nulls Using Evolutionary Computing Technique |
| Abstract: | Beamforming is a desirous technique in wireless communication by which the desired signal is filter spatially from the interference environment. In this paper, the Firefly algorithm (FFA) is used to demonstrate such beamforming characteristics in linear arrays using amplitude only technique. The amplitude only technique is effectively employed with the FFA to synthesize the linear arrays with desired radiation characteristics. The generated radiation patterns have single and multiple nulls with no constraint imposed on beam width or side-lobe level. The beam steering characteristics are also studied using the same methodology. |
| Author(s): | M. L. M. Lakshmi, K. Rajkamal, S. V. A. V. Prasad, Md. Z. U. Rahman |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 11 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1919 KB |