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Title: ACES Journal December 2018 Cover
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: ACES Journal December 2018 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: ACES Journal December 2018 Full
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: On the Numerical Dispersion of the Radial Point Interpolation Meshless (RPIM) Method in Lossy Media
Abstract: A general formula for numerical dispersion of the two-dimensional time-domain radial point interpolation meshless (2-D RPIM) method is analytically derived. Numerical loss and dispersion characteristics of the RPIM method with both Gaussian and multiquadric basis functions are investigated. It is found that numerical loss and dispersion errors of the RPIM vary with types of basis functions used and associated parameters, number of the nodes, and medium conductivities. In addition, condition numbers of the moment matrix of the meshless methods can also increase numerical dispersion errors. With a reasonable condition number of the moment matrix, the radial point interpolation meshless methods perform generally better than the FDTD method in terms of numerical dispersion errors.
Author(s): X. Zhang, Z. Chen, Y. Yu
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Eigenvalue Decomposition Approach for Beampattern Synthesis
Abstract: The relation between the manifold matrix of the array and the synthesized beampattern is investigated. The synthesized beampattern can be obtained by eigenvalue decomposition of the projection matrix of the array manifold matrix, while the least square error reaches the minimum. For an antenna array whose manifold matrix has been determined, the projection matrix can be derived easily from the array manifold matrix. Then, eigenvalue decomposition of the projection matrix is implemented to obtain the synthesized beampattern. The antenna element excitations can be obtained by an ameliorated least square method. The results of the simulations compared with the traditional least square method show that the matching degree between the targeted beampattern and the synthesized beampattern of the new method is higher and that the new method is more efficient.
Author(s): J. Chen, Y. Yin
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Discontinuous Galerkin Finite Element Time Domain Method for Analysis of Ferrite Circulator with Non-conforming Meshes
Abstract: In this paper, a Discontinuous Galerkin finite element time-domain method (DG-FETD) based on non-conforming hybrid meshes is presented for analysis of the ferrite device. The DG-FETD method with explicit difference scheme is firstly used to analyze the electromagnetic characteristics of complex medium such as ferrite material to reduce memory requirement and computational time. The recursive convolution (RC) method is applied into DG-FETD to deal with the constitutive relation of ferrite material. What’s more, the non-conforming hybrid mesh method with tetrahedron-hexahedron is employed to improve the flexibility and accuracy in mesh processing and reduce the number of unknowns. Numerical results show the efficiency of the proposed method.
Author(s): M. Li, X. D. Ye, F. Xu, N. M. Luo
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Time Domain Parabolic Equation Method for Scattering Analysis of Electrically Large Coated Objects by using Impedance Boundary Condition
Abstract: The time domain parabolic equation method (TDPE) is an efficient tool for analyzing electromagnetic (EM) scattering by electrically large objects. It reduces the cost of computational resources by dividing threedimensional solution space into multiple twodimensional transverse planes for calculating scattered fields one by one. For thin coated perfectly electrically conducting (PEC) objects, the efficiency of TDPE method will decrease if dielectric is considered to be meshed. As an approximate method, Leontovich impedance boundary condition (IBC) handles this problem by modeling a surface impedance on the outer surface of coating dielectric, instead of solving Maxwell's equations in the dielectric domain. Thus in this paper, TDPE method based on Leontovich IBC is proposed to analyze broadband scattering problems of large-scale coated PEC objects. Numerical results have validated the accuracy and efficiency of the proposed method.
Author(s): L. Guan, S. Tao
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Fast Wideband Electromagnetic Analysis Using the Interpolation Technique and Fast Generating Matrix Method
Abstract: A fast wideband electromagnetic scattering analysis method based on the interpolation technique and fast generating matrix method is proposed. By factoring out the dominant phase term, the matrix element is transformed into the element which fluctuates slowly with frequency. The matrices over the frequency band are fast generated via interpolation technique. Instead of employing different meshing grids at different frequencies, this new method requires only one mesh generated at the highest frequency of the given bandwidth. This approach not only saves much work in geometrical modeling but also leads to less time for wideband scattering problem. The proposed algorithm is implemented in the platform of FGG-FG-FFT, which is not sensitive to both the grid spacing and the expansion order. A method for fast generating matrix also is introduced to speed up filling the near matrix. Consequently, it can not only reduce the impedance matrix filling time in the whole frequency band but also accelerate the matrix filling process at frequency interpolation sampling points. Several numerical examples are provided to demonstrate the correctness and the efficiency of the proposed method for the wideband scattering analysis.
Author(s): W. B. Kong, X. F. Yang, F. Zhou, J. Y. Xie, R. G. Wang, K. L. Zheng
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: A Study on Upper Limit Frequency of Symmetric Extended TEM Cells
Abstract: TEM Cells is a commonly used electromagnetic field test device. The upper limit frequency of the TEM Cells is limited to the first resonant frequency. Through the electromagnetic numerical simulation, this paper analyzes the resonant frequency law of high-order modes and studies the resonant frequency characteristics and the upper limit of the frequency of symmetrically extended TEM Cells. Studies have shown that there is an error in the estimated value of the Xmn parameter used in the conventional standard TEM Cells resonant frequency calculation method, which may lead to errors in the order of the resonant modes. Symmetrically extended TEM Cells do not change the original resonant frequency, but because of the coupling modes of even mode and odd mode between two cell units, each of the original resonant frequencies will split two close resonant frequency.
Author(s): C. Song, X. Fu, F. Dai
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: On the Correction of the Probe Positioning Errors in a Non-Redundant Bi-Polar Near to Far-Field Transformation
Abstract: An effective procedure allowing one to correct the positioning errors in a bi-polar near to farfield transformation (NTFFT) technique, that requires a minimum number of near-field (NF) data, has been here assessed from the experimental viewpoint. This NTFFT utilizes an optimal sampling interpolation formula, got by considering the antenna under test as contained in an oblate spheroid and applying the non-redundant sampling representation to the probe measured voltage, to precisely determine the NF data needed by the standard NTFFT with plane-rectangular scan from the voltages at the points prescribed by the sampling representation. These voltages are not known and are accurately recovered from the positioning errors affected measured ones by applying an efficient singular value decomposition based technique.
Author(s): F. D’Agostino, F. Ferrara, C. Gennarelli, R. Guerriero, M. Migliozzi
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Far Field Reconstruction based on Compressive Sensing with Prior Knowledge
Abstract: Far field reconstruction in a large-scale space is time consuming and imprecise. However, if these data are sampled randomly and can be sparse on a specific transform domain, it will become quick and accurate to complete the field reconstruction by using the compressive sensing (CS). By taking the feature of the far field distribution for the half-wave dipole antenna in half space as an important prior knowledge, the sparse transform can be chosen appropriately. Moreover, a piecewise approximation method is presented to reconstruct the far field. The simulated results show that this proposed method has better performance for far field reconstruction than the traditional method.
Author(s): B. Li, W. Ke, H. Lu, S. Zhang, W. Tang
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: A Review of the Modal Decomposition Matrix for Calculating the Far Field of an Infinitely Flanged Rectangular Waveguide
Abstract: We determine the radiation from an infinitely flanged rectangular waveguide using the modal decomposition matrix (MDM) method. The MDM method computes the electromagnetic field components at the aperture in the Fourier domain by representing the radiated field in terms of a sampling of the free-space transverse wave number. The results of the MDM approach show good agreement with numerical approaches using commercial electromagnetic modeling software.
Author(s): G. A. Mitchell, W. Wasykiwskyj
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Using Superformula to Miniaturize CPW Rat Race Coupler
Abstract: This paper proposes a new CPW rat race coupler whose shape has been meandered using the superformula for size reduction. The coupler operates at a center frequency of 1.8 GHz. The size reduction in the proposed design is about 74% as compared to conventional ring rat race coupler. The bandwidth of the proposed coupler defined by |S11| < -15 dB is about 31.6%.
Author(s): A. A. Omar, N. I. Dib
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: A Miniaturized Antenna with Optimum Q-Factor and High NFD for UWB Microwave Imaging
Abstract: This paper presents an ultra-wideband (UWB) micro-strip patch antenna design for microwave breast phantom imaging system. By optimizing the shape of radiating elements, the antenna achieves UWB characteristics with excellent frequency ratio. The antenna was fabricated and tested in both time and frequency domain analysis. Sufficient agreement between the simulated and measured data was observed. The antenna achieves a wider bandwidth of 8.2 GHz (2.5 GHz to 11.2 GHz) with good gain and radiation pattern. The antenna has optimum design comparing to the theoretical Qfactor and the near field directivity (NFD) is also observed. Effective near-field microwave breast phantom measurement systems with an array of 9 UWB antennas is proposed and the performance is tested with and without tumor cells inside the breast phantom. The backward scattered signals analysis shows that the presence of tumor with higher dielectric constant than normal cells. Thus, the proposed antenna can be a good candidate for microwave breast tumor detection.
Author(s): M. T. Islam, M. Samsuzzaman, I. Yahya
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Powering Sensors in IoT System by Using Compact Seven Band PIFA Rectenna
Abstract: A compact seven band coplanar waveguide fed planar inverted F antenna (PIFA) is presented. The proposed antenna is designed to harvest the ambient radio frequency energy at GSM 900, GSM 1800, LTE band 11 and 7, UMTS 2100, Wi-Fi 2.4, LTE and WIMAX 5.2. The antenna is simulated using 3D electromagnetic simulators CST and HFSS. Moreover, the antenna is fabricated and it is used to measure the indoor RF spectrum in Egypt. A simple AC to DC converter unit is designed by using HSMS 2850 Schottky diode to convert the collected RF energy to DC energy. The antenna and the AC to DC converter are integrated to form the RF energy harvesting system. The maximum measured efficiency obtained at 2.4 GHz is about 63.7%.
Author(s): N. A. Eltresy, D. M. Elsheakh, E. A. Abdallah, H. M. Elhennawy
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Linearization of S-Parameter Cascading for Analysis of Multiple Reflections
Abstract: This paper develops a method to derive intuitive understanding of the root causes of reflective interference created by the many impedance discontinuities between the packages, PCBs and connectors. Scattering parameters are cascaded to describe the system response and linearized to analyze the multiple reflections. An upper error bound of the linearization is derived and is validated with Monte Carlo studies.
Author(s): R. J. Allred, C. M. Furse
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Biomimetic Radar Target Recognition Based on Hypersausage Chains
Abstract: A biomimetic radar target recognition method is proposed in this paper. From a geometrical perspective, the high resolution range profiles of radar targets are considered as points in high-dimensional feature space. Hypersausage chains are used to cognize the low-dimensional manifold embedding in the high-dimensional space. The topological framework construction algorithm for a hypersausage chain is improved and described in detail. A procedure for a reasonable selection of the hypersphere radius is also involved, which guarantees both acceptable generalization capability and excellent rejection capability of the classifier. The performance of proposed method is compared with the commonly used support vector machine (SVM) method with a radial basis function kernel or a polynomial kernel. Simulation results show that our proposed method outperforms the SVM methods in anti-noise capability, generalization capability and especially rejection capability.
Author(s): H.-H. Zhang, P.-Y. Chen
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: SAR Electromagnetic Image Conditioning Using a New Adaptive Particle Swarm Optimization
Abstract: In Synthetic Aperture Radar (SAR) image Objects or region detection is a difficult task because of improper variation of boundary due to speckle noise. So, it creates the problems of human being for the analysis. In fact, this process leads to inaccurate in the detection and measurement of object parameters. In this paper proposes a new automatic detection of objects from SAR images. For detection of objects an effective method is introduced using the variance of Particle Swarm Optimization (PSO) called Adaptive PSO (APSO). In this paper develops the dynamically varying the inertia weight for PSO and tuning the social components, cognitive components. This APSO find the optimal threshold value for making the better segmentation by preprocessing SAR image with effective Filter. The proposed APSO method has also compared with existing methods in terms of detection of object regions and parameter calculations.
Author(s): B. M. Reddy, M. Z. U. Rahman
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: A Study on the Distribution and Uniformity of Symmetric Extended TEM Cells
Abstract: TEM Cells can generate computable standard fields, which are often used in electromagnetic measurement systems. Their electromagnetic field uncertainty has a great influence on the evaluation of system measurement results. In this paper, a method and index for rigorous evaluation of the uniformity of electromagnetic field distribution in the test area are presented. The relationship between different measurement accuracies and the size limits of the test object is analyzed by HFSS. According to this relationship, the limit condition of the sample size is established when the E field measurement accuracy is 1dB. Among them, the height requirements are consistent with the traditional experience requirements, and the width requirements are more stringent. On this basis, the electric field distribution law of the symmetric extended TEM chamber is studied and analyzed. It shows that the field uniformity of the symmetric extended TEM room is basically unchanged when the test space is multiplied.
Author(s): C. Song, Y. Jin, F. Dai
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Air Plasma Key Parameters for Electromagnetic Wave Propagation at and Out of Thermal Equilibrium: Applications to Electromagnetic Compatibility
Abstract: This article addresses the importance of accurate characterization of plasma parameters for electromagnetic compatibility (EMC) purposes. Most of EMC issues involving plasma materials are obviously multi-physics problems (linking chemical, mechanical, thermal and electromagnetic wondering) with deep interactions. One of the main objectives of this paper is to establish the theoretical effect of thermal nonequilibrium of the plasma on electromagnetic wave propagation. This will be characterized throughout plasma key parameters (including complex permittivity). Numerical simulations based upon Finite Integral Technique (FIT) will demonstrate the EMC interest of this methodology for shielding purposes and general air plasma.
Author(s): P. Andre, G. Faure, A. Mahfouf, S. Lallechere
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Fast Calculation of the Filamentary Coil Impedance Using the Truncated Region Eigenfunction Expansion Method
Abstract: The paper presents a mathematical model of an ideal filamentary coil with a finite number of turns, derived by means of the method called truncated region eigenfunction expansion (TREE). The proposed solution allows quick computation of the filamentary coil impedance as well as of the impedance changes caused by the presence of a two-layered conductive material. The final formulas were presented in the closed form and implemented in Matlab. The results were verified using the finite element method in the COMSOL Multiphysics package as well as by means of other mathematical models. In all cases they show a very good agreement. The obtained values of coil impedance changes were compared in terms of the time of reaching the final results. In the case of the most significant calculations, which consisted of many iterations, the proposed solution turned out to be by far the fastest one.
Author(s): G. Tytko, L. Dziczkowski
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Analytical Modeling of Magnetic Field Considering the Saturation in Switched Reluctance Motor
Abstract: This paper aims at accurately predicting the severe magnetic saturation of a switched reluctance motor (SRM). Firstly, Method I based on the solution of the Laplacian or Poissonian field equation is used to predict the magnetic field in the air gap, but this method is only applicable to the mildly saturated magnetic field. Secondly, Method II based on the winding function theory (WFT) considering the saturation is utilized to predict the magnetic field, which can precisely compute the severely saturated magnetic field. Nevertheless, the tangential magnetic flux density is not considered by Method II. Finally, the synthetic method based on the advantages of Method I and Method II is proposed, which can predict the air-gap magnetic field in SRM having any number of stator slots and rotor poles for any rotor positions. The results indicate that the error of the air-gap magnetic field obtained by the synthetic method is within 5%. Moreover, the radial electromagnetic force and torque obtained by the Maxwell Stress equation are compared with the results computed by the FEM, verifying the effectiveness of the synthetic method. It lays the groundwork for the optimization of torque ripple, vibration and noise of SRM.
Author(s): S. Hu, S. Zuo
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Characterizations of Magnetic Field Distributions inside Buckling Pipelines
Abstract: High internal temperature and pressure often induces the subsea pipelines to buckle and then crack. This paper exposes the magnetic field distribution characterizations inside buckling pipelines in order to detect the buckling via magnetic measurements. J-A force-magnetic coupling model is used to obtain the permeability mu r as a function of the stress sigma. Finite element method with multiphysics coupling is deployed to calculate the magnetic fields inside the buckling pipe with different magnetizations, temperatures, and pressures by importing the mu r-sigma curve. The results demonstrate that complicated stress fields cause the magnetic fields inside the buckling pipe to have many noticeable characteristics that can be deployed to reliably and precisely identify the buckling. The signs and magnitudes of the buckling stress vary significantly in different cross-sections, and even reverse at the buckling starts, where the axial and radial components have two peaks and two peak-valleypeaks symmetrically distributed about the middle plane, respectively. The magnetic fields can reveal tiny buckling with stress but without visible deformation.
Author(s): Y. Zhang, Y. Xue, X. Huang, J. Li, S. Chen
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: A Novel Approach for Intruder Localization Based on Leaky Coaxial Cable Sensor with IQ Demodulation and Synchronous Subtraction
Abstract: Some aspects of the intruder detection system (IDS) based on the leaky coaxial cable (LCX) sensor are still unknown due to its complex propagation characteristics. In order to study the field disturbance mechanism of human intruder and to reduce the phase error caused by the initial state of the detection signal, a novel method of improving the localization accuracy is proposed. At the frequencies of 40MHz, 100MHz and 200MHz, the IDS based on the LCX sensor is proposed by analyzing the scattering characteristics of human intruder and using IQ demodulation method. According to the characteristics of the IDS, the electric field distribution is obtained by irradiating the human intruder from three typical radiation directions, which are front, side and low-side direction in the mentioned frequency range. Combined with the method of pulse accumulation and synchronous subtraction, the intruder localization can be easily realized by using pulse delay positioning method. The results demonstrate the improvement in localization accuracy and the decrement in false positive rate, and the positioning accuracy is less than 3 meter.
Author(s): Q. Guan, H. Lu, K. Wang, C. Chen
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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Title: Calculation and Analysis of an Analytical Model for Magnetic Field Monitoring Based on TREE in Eddy Current Testing
Abstract: In this work, theoretical model for magnetic field monitoring rather than traditional detection of coil impedance is investigated and analyzed. The truncated region eigenfunction expansion (TREE) method [1] offers analytical expressions by truncating the solution region to a finite length, so magnetic field can be derived in a series of proper eigenfunctions instead of the integral form, as it traditionally happens. The influences of truncation interval h, the number of summation n and excitation current frequency f on magnetic field above conductive plate for the model accuracy are estimated. The comparison of the results obtained between theoretical calculation and the finite element method shows excellent agreement under certain conditions. An applicative example is presented to assess the proposed theory to different conductor problem using the eddy current field derived by the analytical solution. The analytical model can be beneficial for analysis, parametric studies and development of eddy current testing system.
Author(s): F. Jiang, S. Liu
File Type: Journal Paper
Issue:Volume: 33      Number: 12      Year: 2018
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