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Title: ACES Journal March 2020 Cover
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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Title: ACES Journal March 2020 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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Title: ACES Journal March 2020 Full
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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Title: RF Magnetic Field Profiling with a Dielectric Bore Lining for Traveling Waves in a 3-T MRI Scanner: A Computational Study
Abstract: Traveling-wave magnetic resonance imaging (MRI) can be advantageous over the classical, quasistatic or near-field MRI. However, it is restricted to ultra-high static magnetic fields in the scanner and the correspondingly high RF excitation magnetic field frequencies due to fundamental constraints in cutoff frequencies of the MRI bore, considered as a waveguide. Through a computational study, we propose translating traveling-wave ideas to a 3-tesla scanner, where the RF magnetic field frequency is 127.8 MHz, using a highpermittivity dielectric layer (lining) that is built into the bore. With the lining, we can achieve traveling-wave modes inside the imaging phantoms even at 3 T, where this is generally not possible. We present results obtained using the higher order method of moments in the surface integral equation formulation, previously established as an efficient, accurate, and reliable technique for modeling of RF fields in MRI applications. Our simulations of a simple circularly polarized RF probe and dielectric lining give rise to a considerably uniform circularly polarized RF magnetic field inside phantoms in the clinical scanner.
Author(s): M. M. Ilic, A. A. Tonyushkin, P. S. Athalye, N. J. Sekeljic, A. J.M. Kiruluta, B. M. Notaros
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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Title: Application of Barycentric Subdivision Method for Singularity Integration in Method of Moments
Abstract: Method of moments (MoM) is an essential tool to model electromagnetic wave interactions with three-dimensional targets. Numerical integration is a key technique in MoM. Due to the singular nature of Green's function, MoM requires special treatment in the calculation of singular integration, which is usually timeconsuming. In this study, the barycentric subdivision method is investigated to compute numerical integration in three-dimensional surface integral equations. This method allows a uniform treatment for both singular and non-singular integrals. Numerical examples show that this method could reach the same level of accuracy as the singularity extraction method for RWG basis functions, and the computational time of setting up the matrix can be reduced by half.
Author(s): C. Xiang, X. Dang, M. Li, F. Yang, S. Xu
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
Download Link:Click here to download PDF     File Size: 1882 KB

Title: Analysis of Infrared Nano-antennas Material Properties for Solar Energy Collection
Abstract: This work presents the effect of material properties on three infrared nano antennas that are rectangular, bowtie, and elliptical-shaped designed to collect a maximum field in the gap between the two dipole arms over a frequency band of 28-29THz. The dipole shapes are comprised of conducting dipoles printed on a dielectric substrate. The bowtie is designed to be curved with an exponential shape, and itis found to collect a higher value of the electric field in the gap than do the other two shapes. The above antennas are investigated with different materials for the dipoles and the substrate to study the effect of material variation on the electric field collected in the dipole gap. Three different types of conducting materials, namely, gold, chromium, and titanium are used. It is found that the collected gap field intensity is directly proportional to the conductivity of the dipole material. The effect of three different types of substrates; quartz (GaAs), silicon, and SiO2 on the collected gap field is also investigated.
Author(s): W. Amara, T. Aguili, A. Alghamdi, D. Oueslati, N. Eltresy, M. Sheikh, H. Rmili
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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Title: Radar Cross Section Reduction using Characteristic Mode Analysis
Abstract: This article covers the application of Characteristic Mode Analysis to reduce the Radar Cross Section of a canonical object, a metallic cylinder. Electrically small, non-resonant slots are added to the structure and loaded with complex impedances, positioned on hot spots found after mode analysis based on the Method of Moments. Two critical frequencies with higher amplitude radar cross-section, 400 and 450 MHz, were analyzed. Results showed monostatic reductions on average of 5 dB, in both frequencies for two different sets of loads and at two different incident angles. Radar cross-section patterns were found to be affected by the load impedances, thereby offering a low profile and low drag solution to control the backscattering signature pattern.
Author(s): M. B. Perotoni, F. A. A. da Silva, K. M. G. dos Santos, D. B. Almeida
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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Title: Array Pattern Reconfiguration Using Pixel Method
Abstract: In this paper, the array elements are considered as pixels and their magnitude excitations are assigned to the values of 1 (i.e., active or turned ON) or 0 (i.e., inactive or turned OFF). Thus, each element either exists at its position in the considered array or not. The proposed pixel method can be applied to different planar array configurations such as square, rectangular, triangular, circular, or any other shape to achieve the required pattern reconfigurability. Moreover, by turning OFF some of the selected elements, the main beam of the array pattern can be switched to specify directions without using any phase shifters or any other RF components. Therefore, its practical implementation is simpler and cheaper than any other existing method. However, when comparing with arrays in which all their elements are turned ON, the gain of the considered arrays will be reduced when some selected elements are turned OFF. The array pattern reconfiguration using the pixel method has been designed and its parameters have been optimized using computer simulation Technology (CSTMWS), which uses the Finite Integration Technique (FIT). It’s also verified by High-Frequency Surface Structure (HFSS) commercial software (based on the FEM method). Numerical results obtained under fullwave modeling CST environment demonstrate the effectiveness of the described method.
Author(s): K. M. Younus, J. R. Mohammed
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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Title: Design and Analysis of Reactive Load Dipole Antenna using Genetic Algorithm Optimization
Abstract: This article presents a reactive load dipole antenna and it is working in the frequency range from (10 MHz- 600 MHz). The LR Load can improve the antenna characteristics to produce maximum gain. The loads are in the combination of parallel and series LR circuits. Genetic Algorithm is used to obtain the optimum values of loads and their optimum position along the dipole. The proposed design is simulated using 3D EM CST Microwave Studio tool. In the working band, the S11 parameter and gain of the loaded antenna are -15.73 dB at 328 MHz and from -15 dBi at 10 MHz to 2.80 dBi at 600 MHz. An optimized reactive load dipole antenna were fabricated and tested. Good agreement were attained among the measured and simulated results.
Author(s): K. Kayalvizhi, S. Ramesh
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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Title: A Design of OAM Metal-only Transmitarray Antenna Using High-Transmission Slot-Type Jerusalem Elements
Abstract: In this paper, an orbital angular momentum transmitarray antenna based on high-transmission slottype Jerusalem elements is proposed. The equivalent circuit model of the proposed element is analyzed by the transmission line theory. Theoretical results calculated by MATLAB show that a four-layer element with non-identical layers can realize a similar phase range and a much higher transmission efficiency as that with identical layers. Using this method, the transmission magnitude is greater than −0.45 dB within a 360° transmission phase range. Based on the proposed element, a round aperture orbital angular momentum transmitarray composed of 648 elements is designed and simulated by HFSS. The results confirm that orbital angular momentum waves with l=+1 are successfully generated. The divergence angle and maximum gain are about 6° and 19.2 dBic, respectively. And the aperture efficiency with l=+1 is 11.3%.
Author(s): L. Yu, X. Li, H. Zhu, Z. Qi
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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Title: Arbitrary Shaped Objects Detection and Reconstruction through Overset Grid Generation Method with B2-spline Interpolation in Forward-Backward Time-Stepping Inverse Scattering
Abstract: Finite-Difference Time-Domain (FDTD) method is a simple and powerful tool used to solve electromagnetic (EM) problems. However, the drawbacks of FDTD method are difficult to model the curved boundaries and small features due to its restriction to inherent orthogonal grids. We have previously proposed that the B2-spline or biquadratic spline interpolation technique for Overset Grid Generation and Finite- Difference Time-Domain (OGG-FDTD) method be utilised to overcome the limitations of FDTD method. This proposed method has the ability to accurately measure a scattered field around an unknown object. In this paper, the OGG-FDTD method with B2-spline interpolation in Forward-Backward Time-Stepping (FBTS) inverse scattering technique was proposed for the detection and reconstruction of arbitrary shaped objects in Case A and malignant breast tumour detection in Case B. The results showed that the Mean Square Error (MSE) of reconstructed dielectric profiles by using the proposed method has achieved significantly lower values than the FDTD method in FBTS. In Case A, the accuracy difference between the two methods was 26.67% for relative permittivity and 27.63% for conductivity, respectively. In Case B, it was found that the implementation of the proposed method increased the accuracy of reconstructed the relative permittivity image by 50.54%, and conductivity by 74.42% as compared to the FDTD method in FBTS technique. Furthermore, the values of normalised error function for the proposed method were also lower than the FDTD method in FBTS. Hence, it is proven that this numerical method can provide clearer and better reconstructed images to improve the quality of retrieve the dielectric profiles of the investigation area.
Author(s): B. S. Wee, K. A. H. Ping, S. Sahrani, T. Moriyama
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
Download Link:Click here to download PDF     File Size: 1982 KB

Title: A New Method for Predicting Crosstalk of Hand-Assembled Cable Bundles
Abstract: Hand-assembled cable bundles are random harness whose crosstalk is difficult to obtain accurately. A crosstalk prediction method of hand-assembled cable bundles is proposed in this paper. The harness is modeled by means of the mean pseudo-random number based on the cascade method. The factors considered in the model include the random exchange of wires position in the wiring harness cross section and the random rotation of the cross section to the ground. A mathematical description of the random exchange of wires position is made by using the row and column transformation of the per unit length RLCG parameter matrix. BP neural network with strong nonlinear mapping ability is introduced to describe the random rotation of wiring harness to the ground. Combined with the finitedifference time-domain (FDTD) method, the crosstalk of the wiring harness is predicted. Experimental results show that the new method has good accuracy in predicting crosstalk of hand-assembled cable bundles. The higher the twisting degree of the wiring harness is, the more concentrated the crosstalk is.
Author(s): C. Yang, W. Yan, Y. Zhao, S. Wang, Q. Liu
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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Title: A K-band Spoof Surface Plasmon Polaritons Bandstop Filter with Capacitively Loaded Split-ring Resonator
Abstract: A K-band bandstop filter based on the spoof surface plasmon polaritons (SPP) and the capacitively loaded split-ring resonator (RSS) is proposed in this paper. The capacitively loaded RSS consists of two parts: the traditional rectangle RSS and a T-type stub placed at the center of the arm microstrip line of the rectangle RSS. Thanks to the capacitively loaded RSS, the operating frequency of the resonator is reduced, which is helpful for miniaturizing the circuit size. The dispersion feature of the capacitively loaded RSS is studied by simulation and the geometrical parameters effects on the filter’s final performance are discussed. A K-band bandstop filter with spoof SPP and capacitively loaded RSS is designed, fabricated and measured to verify the proposed design methodology. The measured results show that the bandstop filter works at 21.05 GHz-22.95 GHz with more than 40 dB insertion loss.
Author(s): P. Chen, L. Li, Z. Wang, K. Yang
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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Title: Influences of Amplitude Tapering and Feed Blockage on the Radiation Characteristics of Ku-Band Parabolic Reflector Antennas
Abstract: In this work, the influences of amplitude tapering and feed aperture blocking in gain and first sidelobe level of Ku-band parabolic reflector antennas are investigated. Two different parabolic antenna configuration groups are proposed to determine each of these degradation factors. Designed parabolic reflectors are fed by pyramidal and conic horns to observe the blockage effect of feed type on Ku-band satellite reception applications. In the first examination to designate the influence of illumination loss due to amplitude tapering four parabolic reflectors are designed with 8 dB, 10 dB, 15 dB and 20 dB edge taper values on reflector apertures. Thereafter, thanks to the reflectors designed with the same edge taper value, but having different diameters, it became possible to observe, purely the influence of feed blockage on the radiation characteristics. Both theoretical and simulated patterns of reflector systems are presented.
Author(s): N. T. Sonmez, F. Tokan
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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Title: Wideband Low Profile Multi-Polarization Reconfigurable Antenna with Quasi-cross-shaped Coupling Slot
Abstract: A wideband low profile multi-polarization reconfigurable antenna with quasi-cross-shaped coupling slot is proposed. The antenna consists of an upper oval radiating patch, the quasi-cross-shaped coupling slot, fork-shaped folded feed lines and a reconfigurable Wilkinson power divider network with four pairs of p-in diodes. The antenna reconfigurable polarization modes change among ±45° Linear polarization (LP), dual-LP, left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) by controlling the ON/OFF states of the p-i-n diodes. The designed prototype has been fabricated and measured. Good agreement between the measured and simulated results is achieved. Measured results show that the antenna has wide impedance bandwidth (over 21.35% for LP and 17.70% for CP) and axial ratio (AR) bandwidth (16.13% for LHCP and 16.88% for RHCP). The average realized gains are about 7.6 dBi for different polarization modes. The proposed antenna has the advantages of multi-polarization reconfigurable ability, wide bandwidth, low profile, and high gains, which make it possible to be applied to wireless communication systems.
Author(s): Q. Xu, Z. Liu, S. Liu, X. Kong, Z. Huang, B. Bian, Q. Yu, J. Qin
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
Download Link:Click here to download PDF     File Size: 1903 KB

Title: Assessment of Human Exposure in Case of Wireless Power Transfer for Automotive Applications using Stochastic Models
Abstract: In this paper, different non-intrusive stochastic approaches are compared in view of human exposure assessment from an inductive power transfer system at 85 kHz, dedicated to automotive applications. The stochastic approaches are combined with a 3D finite element method to build adequate meta-models based on Kriging and Polynomial Chaos Expansion. These models are used to consider the uncertainty and variability of several parameters defining the electromagnetic problem. Such fast predictions of uncertainties may help to improve the design of shields for inductive power transfer systems considering health and safety standards.
Author(s): S. Deshmukh, P. Lagouanelle, L. Pichon
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
Download Link:Click here to download PDF     File Size: 1686 KB

Title: Compact Multilayer Substrate Integrated Waveguide Dual-band Filtering Rat-race Coupler Based on Fan-shaped Cavities
Abstract: A new type of multilayer dual-band filtering rat-race coupler based on fan shaped substrate integrated waveguide (SIW) cavity is first proposed in this paper. Resonant frequencies of SIW fan-shaped cavity (SIFC) have been derived to construct a resonant cell. Magnetic and electric coupling between SIFCs are realized through multiple rectangular and circular slots located on metal layer, respectively. Specifically, the multiple rectangular slots are beneficial to increase coupling bandwidth and achieve better amplitude and phase balance. Moreover, the bandwidth ratio and center frequency of two pass-bands can be flexibly controlled by adjusting the size of band-stop resonators. The detailed analysis and the design method based on coupling matrix have been introduced to realize a dual-band filtering rat-race coupler. The new type of component should be able to provide at least three functions simultaneously, including in-phase and out-ofphase power dividing, filtering, and dual-band operation. Compared with other filtering couplers, the proposed design exhibits good dual-band filtering responses, high Q factor, better isolation, amplitude balance, as well as 0° and 180° phase differences.
Author(s): Z. Zhang, Y. Fan, Y. Cheng, Y. Zhang
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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Title: Research on Rotor Position Detection Method of Printed PMSM Based on Leakage Magnetic Field of Rotor
Abstract: With the merits of simple structure, strong stability and high power factor, the application of Permanent Magnet Synchronous Motor (PMSM) have become more and more widespread. Meanwhile, rotor position information of PMSM is of vital importance to motor driving. This paper is mainly to research the rotor position detection of Printed PMSM, and, by applying fluxgate technology into the detection process, the rotor position is determined based on the leakage magnetic field of the rotor. The simulation of the rotor leakage magnetic field is made using Finite Element Analysis (FEA), which verifies the feasibility of rotor position detection methods based on the Leakage Magnetic Field of Rotor. Finally, through the experimental prototype of Printed PMSM and fluxgate sensor, Printed PMSM can be driven using a rotor position detected by fluxgate sensors. Fluxgate sensors have advantages of high resolution, strong anti-interference ability, good stability, wide measurement range and ability of miniaturization design, making it suitable to detect weak leakage magnetic field at the end of the rotor so that Printed PMSM has advantages of integration and easy maintenance. Meanwhile, methods mentioned in this paper/article are also applicable to other kinds of PMSM and have certain guiding significance for the integration design of PMSM.
Author(s): X. Deng, J. Zhou, L. Hao, Z. Fan, N. Liu
File Type: Journal Paper
Issue:Volume: 35      Number: 3      Year: 2020
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