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Title: ACES Journal January 2020 Cover
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
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Title: ACES Journal January 2020 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 830 KB

Title: ACES Journal January 2020 Full
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 14653 KB

Title: A Portable Through-Wall Microwave Imaging System
Abstract: A microwave imaging system requires the design and implementation of an imaging algorithm, a sufficiently sensitive/accurate vector network analyzer, and antennas. This work presents a simple imaging algorithm, design and implementation of a low-cost VNA and antennas that are able to operate at 4 - 6 GHz. The commercial VNAs are of general purpose and are too expensive for microwave imaging applications. The design trade-offs applied to VNA are presented and implemented circuits are demonstrated. Using the presented VNA, a hand-held imaging system is implemented that extracts scattering parameters to create the target image. S-parameters obtained from the preselected filters with the designed VNA are provided to demonstrate the quality of the design. Target images are created for a couple of commonly used walls to demonstrate the overall system performance.
Author(s): H. Aniktar
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 1843 KB

Title: A Simple Planar Antenna for Sub-6 GHz Applications in 5G Mobile Terminals
Abstract: A simple planar antenna for sub-6 GHz applications in 5G mobile terminals is presented. The proposed antenna is composed of one multi-branch driven strip and three parasitic grounded strips, featuring simple design without using three-dimensional structure and lumped elements. The |S11| ≤ -6dB impedance bandwidth of the antenna covers 700-960 MHz and 1600-5500 MHz bands with a compact size of 40×15×0.8 mm3, which makes it fulfill the requirements of sub-6 GHz applications in the 5G terminals. The prototype of the antenna is fabricated, and the design is well validated by experimental results.
Author(s): Z. An, M. He
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 1540 KB

Title: Cross Dipole Antenna for 4G and Sub-6 GHz 5G Base Station Applications
Abstract: Cross dipole antenna for base station applications is presented in this paper. The proposed antenna consists of simple dipole elements and modified balun structure for the improved performance. The proposed design is simple and suitable for 4G and sub-6 GHz 5G base station applications. The antenna is fabricated using low-cost FR4 epoxy substrate with a dielectric permittivity of 4.4. The height of the substrate is 1.6 mm and loss tangent is 0.02. In order to confirm the proposed design, the antenna is measured and compared with the simulation results. The proposed antenna is achieved 13.8 dBi of realized peak gain in the 1.341 to 3.834 GHz frequency range along the bandwidth of 2.492 GHz with VSWR < 1.5. The proposed antenna obtains stable radiation patterns and stable gain over the frequency range. The cross dipole antenna structure with the proper radiation performance makes the proposed antenna suitable for base station applications.
Author(s): G. Gopal, A. Thangakalai
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 1918 KB

Title: Input Resistance Changes and Related Performances of a Normal-Mode Helical Antenna in a Human Body Application
Abstract: Recently, ingestible capsule endoscopy has been developed to ease the dosimetry process in the stomach and tract. In this application, a helical antenna is used because its shape is suitable for a capsule. The electric performance of a coil antenna can be analyzed by the normal-mode helical antenna (NMHA) concept. Previously, the design equations for NMHA have already been developed in free space application. Application of NMHA in the human body is innovative. Antenna design equations and electrical performance should be clarified. Presently, only self-resonant structure equations are clarified. In this paper, fundamental electric performances such as the input resistance, bandwidth and radiation characteristics are clarified through electromagnetic simulations and experiments. As for a human body tissue, the muscle is selected and a muscle phantom is used for measurements. It is made clear, that the input resistance and the bandwidth are increased by the increase of the human body conductivity, while the antenna gains are decreased.
Author(s): N. Q. Dinh, D. T. Dung, Y. Yamada, N. Michishita
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 1994 KB

Title: A Low Profile Miniaturization Low Frequency Wideband Antenna Using Passive Lumped Elements Loading
Abstract: In this paper, a low profile miniaturization low frequency sleeve monopole antenna loaded with passive lumped (PL) elements is proposed, which can be utilized for HF, VHF, UHF, and P band applications. The proposed antenna is fed by coplanar waveguide (CPW) and composed of feeding line, modified T-shaped radiation patch, sleeve structure and loaded passive lumped elements. An original monopole antenna is operating at 231 MHz with a small fractional bandwidth of 31.8%. By modifying the T-shaped radiation patch and adding the sleeve structure, the fractional bandwidth can be improved by 11%. To further enhance its performance, several passive lumped elements are integrated with the antenna. The design procedure is presented and analyzed in detail. The simulated results demonstrate that a fractional bandwidth of 192.2% from 10-500 MHz can be achieved for the proposed antenna system, which is also in agreement with the measured result.
Author(s): Y. Xia, Y. Li, W. Xue
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
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Title: Mutual Coupling Reduction of Dual Polarized Low Profile MIMO Antenna Using Decoupling Resonators
Abstract: This paper presents a resonator based decoupling structure for 2×2 dual polarized array antenna. The designed structure consists of two decoupling resonators placed between the antenna elements. The proposed decoupling structure can effectively enhance the isolation and has negligible impact on the radiation patterns.
Author(s): F. Faraz, X. Chen, Q. Li, J. Tang, J. Li, T. A. Khan, X. Zhang
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 1721 KB

Title: Design Strategy for Compact Bandpass Filters Using Meander Line Resonators
Abstract: The purpose of this manuscript is to present a compact design strategy for bandpass filters using Meander Line Resonators (MLR) in combination with Stub Loaded Resonators (SLR). The proposed resonator has been designed and analyzed using even-odd mode analysis. Open-ended stubs are loaded at an appropriate position in the dual-mode resonator to achieve tri, quad, and quintuple passbands. To reduce the circuit size and create transmission zeros at our desired frequencies, a symmetrical meandered shape resonator is loaded with open-ended identical stubs which are bent towards each other. A design strategy is presented step by step and the approach is validated using simulation and experiments.
Author(s): A. Sami, M. Rahman, H. Ahmad, S. Bashir
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 1458 KB

Title: EMC Coupling Between Two Composite Right/Left-Handed (CRLH) Transmission Lines on PCBs
Abstract: Unintentional electromagnetic coupling (crosstalk) between PCB lands is an important aspect of the design of an electromagnetically compatible product. In this paper, analytical model to predict crosstalk between two composite right/left-handed (CRLH) transmission lines in close proximity on PCBs is developed, and validated with full-wave simulation and measurement results. A cascaded seven unit cells CRLH transmission line (TL) acting as source of the electromagnetic emission was placed in close proximity to another seven unit cells CRLH transmission line acting as receptor of the emission on PCBs. Then the near- and far-end crosstalk voltages induced from the generator CRLH-TL to receptor TL for various separations between them were analyzed. It is shown that the crosstalk voltages computed with developed analytical model agrees well with full-wave simulation and measured results. Furthermore, it is shown that the left-handed capacitance and inductance design parameters of CRLH-TL can be used to reduce the crosstalk voltages induced on the receptor circuit leading to a cost-effective solution for shielding of near-by CRLH-TL receptor circuits printed on PCBs for various engineering applications.
Author(s): Irfanullah, S. Khattak, I. Khan
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 1666 KB

Title: 700 MHz (4G) Indoor Propagation - Measurement and Correlation with Different Numerical Methods
Abstract: This article details the comparison of three different approaches of indoor propagation modeling – Ray Tracing, Dominant Path Model and the empirical Multi-Wall, the latter based on the COST-231. These methods are implemented inside the Altair Winprop suite, and are correlated with measurements taken at the frequency of 700 MHz. The choice of this frequency is due to its future use as LTE (4G) for applications in public security services.
Author(s): M. B. Perotoni, R. D. Araujo, K. M. G. Santos, D. B. Almeida
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 1538 KB

Title: Micro-motion Forms Classification of Space Cone-shaped Target Based on Convolution Neural Network
Abstract: In this paper, the echo models with different micro-motion forms (spin, tumbling, precession, and nutation) of space cone-shaped target are built. Different from the ideal point scatterers model, the radar echo contains the contribution from the complex radar cross section (RCS) of point scatterer vs aspect angle. And a convolution neural network (CNN) model for micromotion forms classification based on the micro-Doppler characteristics in spectrograms is presented. The simulation results show that our method can discriminate different micro-motion forms effectively and the overall accuracy is 97.24%. Different levels of additive white Gaussian noise are added to simulate noise-contaminated radar echo. It has been found that the presented method has a stronger anti-noise ability than support vector machine (SVM). When the Signal-to-Noise Ratio (SNR) of Gaussian white noise is 10 dB, the overall accuracy of our algorithm is 29.79% higher than that of SVM.
Author(s): G. Xu, H. Yin, C. Dong
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 1490 KB

Title: Shallow Water Three-Dimensional Transient Electromagnetic Modelling by Using Fictitious Wave Field Methods
Abstract: The marine transient electromagnetic method is a valuable means for locating mineral resources because of its higher detection resolution as well as other advantages. However, this method is easily affected by the air layer and complex terrain, which significantly increase its calculation times. We addressed this problem by developing a three-dimensional finite-difference method based on the principle of correspondence between the diffusive and fictitious wave fields. Using a fast-iteration formula appropriate for a large time step, solving the Maxwell equations in a fictitious wave field, and the effects of air and seawater parameters on the electromagnetic response in shallow water are discussed. Choosing the first derivative of a Gaussian as a source, the 3D numerical simulation of transient electromagnetics in a shallow water area is realized. Comparing to the existing methods, the effectiveness of the proposed method is verified. The results show that this method enables fast and high-precision numerical calculations for 3D models and provides theoretical guidance for detecting seabed mineral resources in complex geological environments in shallow water.
Author(s): Y. Ji, X. Meng, G. Ren
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 1959 KB

Title: Near-Field Analysis and Design of Inductively-Coupled Wireless Power Transfer System in FEKO
Abstract: Inductively-coupled wireless power transfer (WPT) system is broadly adopted for charging batteries of mobile devices and electric vehicles. The performance of the WPT system is sensitively dependent on the strength of electromagnetic coupling between the coils, compensating topologies, loads and airgap variation. This paper aims to present a comprehensive characteristic analysis for the design of the WPT system with a numerical simulation tool. The electromagnetic field solver FEKO is mainly used for studying high-frequency devices. However, the computational tool is also applicable for not only the analysis of the electromagnetic characteristic but also the identification of the electrical parameters in the WPT system operating in the nearfield. In this paper, the self and mutual inductance of the wireless transfer windings over the various airgaps were inferred from the simulated S-parameter. Then, the formation of the magnetic coupling and the distribution of the magnetic fields between the coils in the seriesparallel model were examined through the near-field analysis for recognizing the efficient performance of the WPT system. Lastly, it was clarified that the FEKO simulation results showed good agreement with the practical measurements. When the input voltage of 10 V was supplied into the transmitting unit of the prototype, the power of 5.31 W is delivered with the transferring efficiency of 97.79% in FEKO. The actual measurements indicated 95.68% transferring efficiency. The electrical parameters; Vin, Vout, Zin, theta, Iin, and Iout, had a fair agreement with the FEKO results, and they are under 8.4% of error.
Author(s): D. Kim, A. T. Sutinjo, A. Abu-Siada
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 2669 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: Shielding Effectiveness of HSD Connector – Simulation and Measurement
Abstract: The goal of designing a shielded High-Speed Data (HSD) connectors is to find the ideal balance between economy and performance. The connectors are a part of many systems and they influence their performance. The connectors should be designed to avoid possible negative effects on system properties. Thus, it is necessary to analyze the shielding effectiveness of connectors to ensure the electromagnetic compatibility (EMC) of the whole system. The transfer impedance is an effective shield parameter used to evaluate the shielding effectiveness of cables and connectors. Based on the analysis of the limitation of available test methods, a 3D model is developed to numerically calculate the transfer impedance of the HSD connector. Even though numerical methods were used, the theoretical foundations necessary to interpret the obtained results are revisited. The theory associated with cable shielding is revisited through solving known equations for the transfer impedance of a coaxial cable with a braided shield and foil.
Author(s): N. Jurgec, I. Vukosav, D. Marinac, B. Trkulja
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 1946 KB

Title: Research on Topology of Axial Flux Permanent Magnet Synchronous Generator
Abstract: Through the comparative study of the TORUSNN and TORUS-NS topologies for the axial flux permanent magnet synchronous generator (AFPMSG), it is shown that the AFG with single stator double rotors topology is suitable for vertical axis wind turbines (VAWT). The basic parameters are designed and their 3D finite element models are established for the two topologies, which are compared and analyzed respectively on the same amount of magnets and windings, the magnetic density, THD value, torque ripple and efficiency. The research shows that the efficiency of TORUS-NN structure is only 0.22% higher than that of TORUS-NS structure with the same amount of magnetic steel, but the torque ripple of TORUS-NN structure is much greater than that of TORUS-NS structure, when the amount of magnet steel and the winding are the same, the efficiency of TORUS-NS structure is 8.5% higher than TORUS-NN structure. Considering their performance and economy, the TORUS-NS structure is superior to TORUS-NN topology structure for VAWT in starting torque and low wind speed. The experimental results and finite element analysis results are within the allowable error range, which verifies the feasibility and superiority of TORUS-NS topology for VAWT.
Author(s): Z. Jun, C. Di, L. Guanghua, Z. Zhenyi, S. Li, S. Dandan
File Type: Journal Paper
Issue:Volume: 35      Number: 1      Year: 2020
Download Link:Click here to download PDF     File Size: 1795 KB