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Title: ACES Journal June 2022 Cover
File Type: Journal Paper
Issue:Volume: 37      Number: 6      Year: 2022
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Title: ACES Journal June 2022 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 37      Number: 6      Year: 2022
Download Link:Click here to download PDF     File Size: 334 KB

Title: ACES Journal June 2022 Full
File Type: Journal Paper
Issue:Volume: 37      Number: 6      Year: 2022
Download Link:Click here to download PDF     File Size: 11093 KB

Title: A New Method for TwistedWire Crosstalk Estimation Based on GA-BP Neural Network Algorithm
Abstract: Based on the research of genetic algorithm (GA) to optimize the BP neural network algorithm, this paper proposes a method for predicting twisted wire crosstalk based on the algorithm. Firstly, the equivalent circuit model of a multi-conductor transmission line is established, combined with the method of similarity transformation, the second-order differential transmission line equations are decoupled into n groups of independent two-conductor transmission line equations, and the crosstalk is finally solved. Then the mathematical model of the twisted wire is established and its structural characteristics are analyzed, and the GA-BP neural network algorithm is used to realize the mapping of the electromagnetic parameter matrix of the twisted wire and the position of the twisted wire. Finally, the mapping relationship is substituted into the transmission line equation, and the near-end crosstalk (NEXT) and the farend crosstalk (FEXT) of an example three-core twisted wire are predicted based on the idea of cascade combined. By comparing with the transmission line matrix method (TLM), it can be seen that the method proposed in this paper is in good agreement with the crosstalk results obtained by the electromagnetic field numerical method, which verifies the effectiveness of the algorithm proposed in this paper.
Author(s): W. Zhang, Y. Wu, J. Ding, Y. Zhao, M. He
File Type: Journal Paper
Issue:Volume: 37      Number: 6      Year: 2022
Download Link:Click here to download PDF     File Size: 1302 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: Computational Analysis for Miniaturization of Tapered Slot Antenna using Elliptical Conducting Loaded Strips
Abstract: In this paper, the computational analysis for miniaturization of antipodal Vivaldi antenna (AVA) by an additional single elliptical loaded strip (SELS) is presented. The performance of the miniaturized antenna is evaluated by finite difference time domain (FDTD) technique, while its performance is also verified by finite element method (FEM). The computational time and cost of the two techniques are also compared to highlight the significance of the most suitable technique for miniaturization of the wideband antenna. It achieves ultrawideband performance with lower cutoff frequency at 0.668 GHz and 19.52% size reduction with suitable gain performance. The proposed compact antenna exhibits good performance in the sub-GHz and ultra-wideband (UWB) frequency ranges, which makes it a suitable candidate for low power energy harvesting systems as well as for ultra-wideband applications.
Author(s): B. Tariq, M. Amjad, A. Aziz
File Type: Journal Paper
Issue:Volume: 37      Number: 6      Year: 2022
Download Link:Click here to download PDF     File Size: 2489 KB

Title: Advanced Numerical and Experimental Analysis of Ultra-Miniature Surface Resonators
Abstract: Many scientific and technological applications make use of strong microwave fields. These are often realized in conjunction with microwave resonators that have small geometric features in which such fields are generated. For example, in magnetic resonance, large microwave and RF magnetic fields make it possible to achieve fast control over the measured electron or nuclear spins in the sample and to detect them with high sensitivity. The numerical analysis of resonators with small geometric features can pose a significant challenge. This paper describes a general method of analysis and characterization of surface microresonators in the context of electron spin resonance (ESR) spectroscopy and spin-based quantum technology. Our analysis is based on the Electric Field Integral Equation (EFIE) and the Poggio-Miller-Chang-Harrington-Wu- Tsai (PMCHWT) formulation. In particular, we focus on a class of resonator configurations that possesses extremely small subwavelength features, which normally would require an ultra-fine mesh.We present several efficient techniques to numerically model, solve, and analyze these types of configurations for both normal and superconducting structures. The validation of these techniques is established both numerically and experimentally by the S11 parameters as well as the provision of direct mapping of the resonator’s microwave magnetic field component using a unique electron spin resonance micro-imaging method.
Author(s): Y. Ishay, Y. Artzi, N. Dayan, D. Cristea, A. Blank
File Type: Journal Paper
Issue:Volume: 37      Number: 6      Year: 2022
Download Link:Click here to download PDF     File Size: 2757 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: Design of Compact Multiband MIMO Antenna Based on Ground Neutralization Line Decoupling
Abstract: A compact, multiband two-port MIMO antenna is proposed in this paper for various wireless transmission networks, where the overall size of the antenna is only 30 × 20 × 1.6 mm3. The proposed MIMO antenna consists of two radiating patches, each of which comprises a semicircle and a semi-regular hexagon, as well as the surface-etched C-slot and U-slot to tailor the antenna’s return loss characteristics. In proposed antenna, a parasitic branch forms when the ground plane’s meandering branches are symmetrically distributed. On one hand, it can increase the ground plane’s effective area and enhance the antenna’s return loss characteristics. A neutralization line, on the other hand, is generated, thereby limiting the current transmission on the ground plane. A cross-shaped slit in the ground’s center is also employed to further promote isolation between the radiation elements. According to obtained results, the antenna can cover the frequency bands 0.67-7.29 GHz, 8.07-12.11 GHz, 14.07-15.41 GHz, and 16.04-22 GHz (S11<−10 dB). Moreover, an RF isolation larger than 18 dB exists between the two ports. Lastly, in terms of ECC, DG, TARC, CCL, and MEG, the diversity performances are all satisfactory.
Author(s): Z. Wang, W. Mu, M. Yang, C. Li
File Type: Journal Paper
Issue:Volume: 37      Number: 6      Year: 2022
Download Link:Click here to download PDF     File Size: 2738 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: 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: Dual-band Dual-polarized Dipole Antenna for Gain and Isolation Enhancements
Abstract: A ±45º linear-polarized cross-dipole with enhanced gain and isolation has been designed as an example for 5G applications in this paper. By adding stepped reflector and combined director, the isolation and radiation performance of the antenna can be improved significantly. According to the experimental results, the bandwidths with reflection coefficient lower than 10 dB in the low frequency band and high frequency band are 9.5% (3.2–3.52 GHz) and 17.5% (3.86–4.6 GHz), respectively. The dual band can cover 3.3-3.6 GHz and 4.4-4.5 GHz for 5G bands proposed by China’s IMT propulsion group. Therefore, the proposed antenna can be widely used in wireless detection, transmission and communication. The isolation of low frequency band and high frequency band can reach above 26 dB and above 22 dB. The average gain is approximately 10.2 dBi in the low frequency band, but the other band is around 6.37 dBi. Compared with commonly used base station antennas, the proposed antenna has been dramatically improved in terms of size, bandwidth, and other electromagnetic properties.
Author(s): P. Chen, L. Wang, Y. Lin, D. Wang
File Type: Journal Paper
Issue:Volume: 37      Number: 6      Year: 2022
Download Link:Click here to download PDF     File Size: 5479 KB

Title: Stacked Metamaterial Patch Antenna Made of Low Permittivity Dielectrics
Abstract: A new concept of “meta-lo” architecture is contributed to build compact and broadband stacked metamaterial patch antennas (SMPAs). The new antennas are featured with planar mushroom metamaterials that are all made of low permittivity dielectrics. These metamaterials work as good alternatives to conventional high permittivity dielectrics, enabling the new antenna to resonate at a much lower frequency. To examine the antenna performances, one SMPA is experimentally demonstrated. The new antenna is observed to have a broad bandwidth of 27% in a volume of 0.26λ×0.26λ×0.107λ. The average antenna gain is 7.1 dBi in the operating bandwidth. The compact and broadband SMPA inspired by the meta-lo architecture is promising to be used in the high-speed mobile communications.
Author(s): B. Zhang, X. Xu, X. Deng, Y. Wang, J. Wei
File Type: Journal Paper
Issue:Volume: 37      Number: 6      Year: 2022
Download Link:Click here to download PDF     File Size: 5047 KB