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Title: ACES Journal October 2017 Cover
Abstract: ACES
Author(s):
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
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Title: ACES Journal October 2017 Front/Back Matter
Abstract: ACES
Author(s):
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 117 KB

Title: ACES Journal October 2017 Full
Abstract: ACES
Author(s):
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 12783 KB

Title: A Time-Reversal FDTD Method for Image Reconstruction in the Presence of Noise
Abstract: A new method for image reconstruction using the time-reversed finite-difference time-domain method (TR-FDTD) in severely noisy environments is presented. The proposed method combines crosscorrelation processing with TR-FDTD to successfully produce clear images even in the presence of large amount of noise in the captured signals. The method’s capabilities are demonstrated through simulations and experiments in the x-band frequency region (8-12 GHz). Behind the wall imaging was used as a test case to validate the method. Numerical and experimental noise were added to corrupt the signals, and images were reconstructed with and without the added noise. The proposed method successfully produced clear images while the standard TR-FDTD method resulted in unrecognizable images. The efficacy and robustness of the proposed technique make it promising for applications including through-wall and buried-objects imaging in noisy environments.
Author(s): A. R. AlAjmi, M. A.Saed
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 2119 KB

Title: Improving the Efficiency of Computing Electromagnetic Fields from a Lossy Dielectric Cylinder due to a Line Source
Abstract: This paper describes analysis of electromagnetic fields from a lossy dielectric cylinder due to a line source. Series solutions for the electromagnetic fields internal and external to the cylinder are derived. Convergence is accelerated using the Watson transformation and the “fast_callable” function in the SageMathTM open source software. The series convergence is increased by a factor of nearly 80 using these techniques. Implementation of the Watson transform is also discussed. Applications include propagation analysis for simulating wireless body area networks and communications with wireless biosensors.
Author(s): G. A. Ellis
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 1938 KB

Title: Derivation and Fast Computation of Dyadic Green's Functions of Magnetic Vector Potential for Unbounded Uniaxial Anisotropic Media
Abstract: The dyadic Green's function of the magnetic vector-potential A (DGFA) for unbounded uniaxial anisotropic media is unavailable in literature but it is needed in numerical computation. The equation of the DGFA was directly derived from the Maxwell's equations. Through the Fourier transform and the inverse Fourier transform, the triple integral form of the DGFA in the spatial domain was obtained. And it was finally simplified to Sommerfeld integrals. In order to verify these formulas, we applied the singularity subtraction technique to evaluate the Sommerfeld integrals rapidly and compared the numerical results with the analytical solutions for degenerated cases for the isotropic unbounded media, as well as the simulated results from a commercial finite element software for uniaxial anisotropic unbounded media. Finally, the effect of the singularity subtraction method was discussed.
Author(s): J. Zhuo, F. Han, N. Liu, L. Ye, H. Liu, Q. H. Liu
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 1965 KB

Title: Performance of a Massively Parallel Method of Moment Solver and Its Application
Abstract: A massively parallel Method of Moment (MoM) solver able to run on 200,000 CPU cores and solve matrices larger than 1.3 million unknowns is presented. The solver implements a novel LU decomposition algorithm based on the Communication Avoiding LU (CALU) scheme. By using a new pivoting policy, the communication between processes is improved enhancing the parallel speed up of the algorithm. Solver effectiveness and performance are demonstrated comparing the results with two of the most important math libraries used by direct dense solvers: the commercial MKL and the open source ScaLapack. Results show how simulation time is reduced significantly thanks to this novel LU decomposition algorithm making possible the simulation of incredibility electrically large problems using MoM.
Author(s): Y. Chen, Z. Lin, D. Garcia-Donoro, X. Zhao, Y. Zhang
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 2131 KB

Title: Hybrid Sparse Reconstruction-Method of Moments for Diagnosis of Wire Antenna Arrays
Abstract: In this work, sparse reconstruction is hybridized with method of moments (MoM) for diagnosis of wire antenna arrays. In the hybrid method, excitation voltages of array under diagnosis are related to near field observations through integral equations (IEs), and IEs are transformed into matrix equations by MoM. Sparse reconstruction is then used to solve excitation voltages of array under diagnosis. Finally, locations of failing elements are found by the solved excitation voltages. The hybrid method models mutual coupling effect by MoM, and it achieves higher diagnosis reliability than sparse reconstruction without mutual coupling consideration. Simulation results are presented to show the validity and advantages of the hybrid method.
Author(s): H. Zhao, Y. Zhang, J. Hu, Z. Chen
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 2067 KB

Title: Real-Coded Genetic Algorithm with Differential Evolution Operator for Terahertz Quasi-Optical Power Divider/Combiner Design
Abstract: This paper describes a modified real-coded genetic algorithm with a differential evolution operator (RGA-DE) for a shaped reflector of terahertz (THz) quasi-optical power divider/combiner. The real-coded genetic algorithm (RGA) is more convenient to define the reflector surfaces as compared to other coding methods. Interpolation method is applied to smooth the sophisticated surfaces. A better searching ability is obtained in a small number of individuals by using the differential evolution operator instead of the conventional crossover operator. So a bionics algorithm combining real-coded genetic algorithm and differential evolution (DE) algorithm has been presented to design the THz quasi-optical multiple-way holographic power-combining circuits. The RGA-DE has been utilized to optimize the coupling coefficient kappa of the field distribution to get close to 1. Two real-world examples operating at 380 GHz and 450 GHz respectively are described. The computed results are verified by using the commercial software FEKO Suite.
Author(s): F. Zhang, K. Song, Y. Fan
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 1630 KB

Title: Design of a Novel Miniaturized Vivaldi Antenna with Loading Resistance for Ultra Wideband (UWB) Applications
Abstract: A compact improved Vivaldi antenna working on 0.8-3.8 GHz was designed by using resistance-loaded and slotting technology. Resistance-loaded can reduce the plane size of antenna and three symmetrical unequal rectangular slots in the antenna radiation part can increase the gain. The improved Vivaldi antenna size is 150×150×0.508 mm3, which can be used in ground penetrating radar. The simulation results and experimental results are presented to validate the performance of the proposed improved structure of Vivaldi antenna.
Author(s): Y. Zhu, D. Su, W. Xie, Z. Liu, K. Zuo
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 2149 KB

Title: Double Lens Antennas in Millimeter-Wave Automotive Radar Sensors
Abstract: In the near future, all newly introduced cars will be equipped with radar based systems enabling safer and more convenient driving. The performance of such systems is directly related with the performance of the antenna front end. Recently, double lens focusing system is proposed. With its high broadside directivity and low scan loss over a wide angular range, it can be considered as a good candidate for future long range radars. In this paper, effects of materials on beam scanning performance of double lens antennas are investigated for millimeter wave radars.
Author(s): N. Sönmez, F. Tokan, N. Türker Tokan
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 1619 KB

Title: Position Optimization of Measuring Points in Voltage Non-contact Measurement of AC Overhead Transmission Lines
Abstract: In this paper, an innovative idea is proposed to realize the voltage non-contact measurement of AC overhead transmission lines (OTLs), which is to reversely calculate the voltage characteristic parameters by using the measured AC electric field data under OTLs. The main challenge to realize the goal is the serious illposedness of the inverse problem. The condition number of the observation matrix K is the main index to reflect the ill-posedness of the inverse problem. Because the matrix K is determined by the positions of OTLs and the measuring points of electric field, it is an effective but often overlooked solution to search the optimal positions of measuring points. In this paper, an improved particle swarm optimization algorithm with the adaptive adjustment of inertia weight is developed to search the optimal measuring positions. The presented examples indicate that the selection of optimal positions for the measuring points significantly improves the accuracy and stability of the inverse solution. Meanwhile, the strong searching ability, fast convergence rate, and high stability of the proposed optimal algorithm are demonstrated as well.
Author(s): D. Xiao, Y. Xie, H. Liu, Q. Ma, Q. Zheng, Z. Zhan
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 1777 KB

Title: Optimization of Permanent Magnet Synchronous Motors Using Conformal Mappings
Abstract: An optimal permanent magnet synchronous motor (PMSM) should be a low cogging torque and a sinusoidal back-EMF. In this paper, different magnetizations and shaping models of permanent magnets (PMs) are investigated for achieving an optimal performance. The technique of slot opening shift is simultaneously implemented on the stator slots for more reducing of the cogging torque. To this end, the conformal mapping (CM) method as an accurate and fast technique is used to calculate the motor performance under each condition. In final, the optimal results obtained through the CM method are verified by comparing with the corresponding results obtained from the finite element method (FEM).
Author(s): B. Rezaeealam, F. Rezaee-Alam
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 2102 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: A Band-Notched Square Monopole Antenna designed for Bandwidth Enhancement in UWB Applications
Abstract: In this letter, a square monopole antenna has been designed for ultrawideband (UWB) applications having variable notch frequency characteristic. The proposed antenna consists of the small square radiating patch with two rectangular slots, which provides a wide usable fractional bandwidth from 3.1 to 14.4 GHz. The proposed antenna is simple and has a very small size of 10×15 mm2. The bandwidth of the proposed antenna is wider than that of the antenna that has already been introduced in references. Experimental results show that the proposed antenna could be a good candidate for ultrawideband (UWB) applications.
Author(s): B. Azarm, C. Ghobadi, J. Nourinia, M. Abbasilayegh, M. Karamirad
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 2041 KB

Title: Compact Design of Wide Bandpass, Symmetric and Asymmetric Dual Bandpass Filters with Finline and Split Ring Resonators
Abstract: The finline based transmission line is used for realization of wide band pass filter. In this paper designing a bandpass filter for wide bandwidth, based on parallel coupled unilateral three finline structures. A design graph for symmetric three unilateral finline structures is presented for the design of bandpass filter. A bandpass filter of order 3 having center frequency of 10 GHz with fractional bandwidth of 20% is designed fabricated and measured. This wide bandpass filter is converted into symmetric and asymmetric dual band pass filters with the help of metamaterials (Split Ring Resonators SRR) on the other side of the finline structure is simulated with High Frequency Structure Simulator (HFSS) and fabricated. Transmission (S21) and reflection (S11) parameters of measured results compared with simulated results.
Author(s): V. Madhusudana Rao, B. Prabhakara Rao
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 1746 KB

Title: An Experimental Study on Microwave Imaging of Breast Cancer with the use of Tumor Phantom
Abstract: Nowadays, breast cancer is the most common type of the cancer among women’s diseases. It is the leading cause of death after cardiovascular diseases. Due to risk of uncontrolled reproduction and propagation of the cancer cells, early diagnosis has a crucial importance. Microwave imaging (MWI) is an evolving method and has a variety of advantages such as operating at lower frequencies with a lower power, cost-effectiveness, and providing comfortable measurements without contact. In this paper, an experimental study on microwave imaging of breast cancer with the use of tumor phantom is presented. For this purpose, an experimental setup containing sand, screw and tumor phantom is prepared as replacement of real tissue. Two-dimensional inverse synthetic aperture radar (ISAR) method is used in handling the scattered electric field data from the measurement setup. Inverse radon transform (IRT) method is then utilized to extract the image of the measured scattering electric field data. The resultant images show that the microwave imaging method can be successfully used together with IRT for the breast cancer problem.
Author(s): M. B. Bicer, A. Akdagli
File Type: Journal Paper
Issue:Volume: 32      Number: 10      Year: 2017
Download Link:Click here to download PDF     File Size: 1749 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