ACES Publication Search
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| Title: | ACES January 2011 Full Journal |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 3857 KB |
| Title: | ACES January 2011 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 915 KB |
| Title: | A Subgridding Scheme Based on the FDTD Method and HIE-FDTD Method |
| Abstract: | To reduce the computer memory and time of the finite-difference time-domain (FDTD) method when the problems are simulated with fine structural features, the subgridding scheme that applies higher resolution only around critical areas is often used. In this paper, a new subgridding scheme is proposed which is based on the hybrid implicit-explicit finite-difference time-domain (HIE-FDTD) method and FDTD algorithm. The field components in fine local grids are updated using the HIE-FDTD method, and in the coarse main grids conventional FDTD method is utilized. Due to the weakly conditional stability of the HIE-FDTD method, the technique achieves the same time marching step in the whole domain as employed in the coarse FDTD scheme, and the need for the temporal interpolation of the fields in the fine grids is obviated, hence, the hybrid HIE-FDTD subgridding scheme is less time consuming and easy to implement. Practical application of hybrid algorithm in the simulation of the shielding effectiveness of an enclosure is reported. |
| Author(s): | J. Chen, A. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 552 KB |
| Title: | Finite Element Analysis of Switched Reluctance Generator under Fault Condition Oriented Towards Diagnosis of Eccentricity Fault |
| Abstract: | In this paper, a novel two phase double layer switched reluctance generator (DLSRG) under static eccentricity fault is introduced and analyzed. The proposed generator consists of two magnetically independent stator and rotor layers. There is a stationary reel, which has the field coils wrapped around it and is placed between the twostator sets. This paper then continues with modeling this generator in the field assisted mode for healthy condition as well as motor with static rotor eccentricity utilizing three-dimensional finite element analysis (3-D FEA). The results of the numerical analysis for a (4/2)×2 DLSRG including flux linkages, mutual inductances per phase in each layer and radial force for various eccentric generator conditions by considering the end effects and axial fringing fields for simulating reliable model are obtained and compared. Consequently, Fourier analysis is carried out to study the variations of mutual inductance as a diagnosis index. The obtained results present useful information as good candidates for fault indicators as well as the amount of eccentricity fault and the direction of fault occurrence. |
| Author(s): | E. Afjei, H. Torkaman |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 320 KB |
| Title: | Hybrid UV/MLFMA Analysis of Scattering by PEC Targets above a Lossy Half-Space |
| Abstract: | An efficient hybrid UV method and the multilevel fast multipole algorithm (MLFMA) is proposed for the analysis of scattering by arbitrary three-dimensional(3-D) perfect electric conductor (PEC) targets above a lossy half-space. The proposed method modifies the MLFMA based on the real-image representation of the half-space dyadic Green’s function. Unlike the original MLFMA, the interaction matrix of the UV/MLFMA is split into the “near” terms, the “intermediate” terms, and the “far” terms. The “near” terms are handled via the method of moments (MoM), the “intermediate” terms are handled via the UV method, and the “far” terms are handled via the MLFMA. The error arising from the approximation to the half-space dyadic Green’s function via the real-image representation in the “intermediate” terms can be avoided by using the UV matrix compression. The memory requirement and computational time of the “near” terms are also decreased significantly compared with the original MLFMA. |
| Author(s): | M. Li, H. Chen, C. Li, R. Chen, C. Ong |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 207 KB |
| Title: | An Alternative Multiresolution Basis in EFIE for Analysis of Low-Frequency Problems |
| Abstract: | An alternative multiresolution (MR) basis is presented for the method-of-moments (MoM) solution of the electric-field integral equation (EFIE) for the analysis of low-frequency problems. The proposed MR basis functions can be treated as an extension of the traditional looptree basis function to hierarchical functions. Similar to the loop-tree basis, the MR basis functions are linear combinations of standard Rao- Wilton-Glisson (RWG) functions. Therefore, the MR algorithm can be easily applied to MoM codes with RWG basis. Since the MR basis is immune from the so-called low-frequency breakdown, the MR basis is especially suitable for the analysis of low-frequency problems. Compared with the previous MR basis, the present MR basis is easier to construct and comprehend, and the basischanging matrix is sparser. Physical interpretation and comparison are given for the previous and present MR bases. Numerical results demonstrate that both the previous and present MR bases are efficient for 3D electromagnetic scattering problems at low frequencies. |
| Author(s): | J. Ding, J. Zhu, R. Chen, Z. H. Fan, K. W. Leung |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 311 KB |
| Title: | Performance Evaluation of State-of-the-Art Linear Iterative Solvers Based on IDR Theorem for Large Scale Electromagnetic Multiple Scattering Simulations |
| Abstract: | The present paper treats with the latest linear iterative solver IDR(s) method and its variants proposed by P. Sonneveld and M. van Gijzen. We derive preconditioned algorithms of the solvers based on right preconditioning and list them. The solvers are numerically tested in terms of convergence and accuracy for the computation of electromagnetic wave scattering from over 104 dielectric cylinders. Consequently, minimization schemes for residual vectors refine not only convergence but also accuracy for the original IDR(s) method. However, a spurious convergence may be confirmed and its influence is 1 or 2 digit error independently of parameter s. |
| Author(s): | N. Nakashima, S. Fujino, M. Tateiba |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 451 KB |
| Title: | A Search-and-Track Algorithm for Controlling the Number of Guided Modes of Planar Optical Waveguides with Arbitrary Refractive Index Profiles |
| Abstract: | A search-and-track algorithm is proposed for controlling the number of guided modes of planar optical waveguides with arbitrary refractive index profiles. The algorithm starts with an initial guess point in the parameter space that supports a specific number of guided modes. Then, it searches for, and tracks, the boundaries of this space or another space supporting a different number of modes. It does so by monitoring the sign of a unified cutoff dispersion function. The algorithm is applied to both symmetric and asymmetric silicon-based parabolic-index waveguides. It shows that unlike asymmetric waveguides, the single-mode condition of symmetric waveguides is controlled by TM-, as opposed to TE-, polarization. This abnormal polarization control is strongest for high index contrast waveguides of sub-micrometer core sizes. The results are verified by the full-vectorial beam propagation method. |
| Author(s): | T. A. Tamadan |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 505 KB |
| Title: | Systems for Homogeneous Electrical Fields Generation and Effects of External Bodies on Field Homogeneity |
| Abstract: | A procedure of modeling new systems consisting of thin toroidal electrodes placed at the surface of a sphere, for high homogeneity electric field generation, is presented in this paper. In order to investigate the influence of an external body shape and volume to the obtained field’s homogeneity, the external object is modeled as a sphere, prolate and oblate ellipsoidal electrode and placed in the centre of the system. Numerical results, obtained using the software Mathematica 7.0 and Femm, are compared and shown graphically. |
| Author(s): | Z. Cvetkovic, B. Petkovic, M. Peric |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 512 KB |
| Title: | Extension of Compact TLM Air-Vent Model on Rectangular and Hexagonal Apertures |
| Abstract: | Compact transmission line matrix (TLM) air-vent model extension, to allow for a computationally efficient modelling of airflow arrays with rectangular or hexagonal apertures, even in the case of significant thickness of a supporting metal panel, is presented. An empirically derived model is introduced as an equivalent circuit into an otherwise coarse TLM mesh to account for the electromagnetic (EM) presence of apertures. The model accuracy and efficiency are validated on several characteristic electromagnetic compatibility (EMC) examples. |
| Author(s): | N. Doncov, B. Milovanovic, Z. Stankovic |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 390 KB |
| Title: | Wideband Compact Antenna with Partially Radiating Coplanar Ground Plane |
| Abstract: | Many of today's portable communication applications require antennas that are compact, broadband, and easily integrable in a big variety of terminal geometries. This paper presents a compact wideband antenna with partially radiating coplanar ground plane. The prototype of the antenna shows a wide bandwidth (VSWR ? 2) of 92% (from 3.53GHz to 9.5GHz). The antenna also exhibits maximum gain of 3.5dBi and stable radiation patterns over the whole bandwidth. Nevertheless, in this paper the significance of the ground planes on the operating bandwidth are examined with the help of current distribution and discussed in detail with supporting parametric analysis. |
| Author(s): | A. T. Mobashsher, M. T. Islam, N. Misran |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 608 KB |
| Title: | Planar Compact U-Shaped Patch Antenna with High-Gain Operation for Wi-Fi/WiMAX Application |
| Abstract: | A planar inverted U-shaped patch antenna with high-gain operation applied for WLAN/WiMAX access point or base station has been proposed and investigated. It provides relatively wider impedance bandwidth of 180 MHz covering the operating bandwidth for WLAN/WiMAX system. The proposed planar patch antenna also provides the directional radiation patterns with maximum antenna peak gain and efficiency of 8.0 dBi and 80% across the operating band, respectively. Only with the antenna size of 44 × 35 × 4.0 mm3, the proposed patch antenna has the compact operation with more than 13% antenna size reduction. |
| Author(s): | J. Lu, H. Chin |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 1 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 391 KB |