ACES Publication Search
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| Title: | December 2008 Full Journal |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 4 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 4045 KB |
| Title: | December 2008 Journal Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 4 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 226 KB |
| Title: | Highly Accurate Implementations of Methods for Handling Singularities on a Planar Patch |
| Abstract: | Three methods for evaluating integrals containing the Green’s function singularity are studied from the standpoint of numerical accuracy at levels required in high order calculations. A significant source of potential error was found to be common to all methods. Suggestions for improving the accuracy of all three are proposed. |
| Author(s): | M. M. Bibby, A. F. Peterson, M. M. Bibby, A. F. Peterson |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 4 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 105 KB |
| Title: | Low-Frequency Full-Wave Finite Element Modeling Using the LU Recombination Method |
| Abstract: | In this paper, the low-frequency instability of full-wave finite element methods (FEM) is investigated. The curl part of the FEM matrix is shown to be singular. The paper explains how low-frequency instabilities are related to this singularity. Based on this analysis, an LU recombination method is implemented in FEM to solve the low-frequency problem. This method, which has previously been applied to the method of moments (MOM), reduces the errors in the curl part of the matrix and enforces the correct gauge condition. Moreover, the method is restructured to work more efficiently for sparse finite element matrices. |
| Author(s): | H. Ke, T. H. Hubing, H. Ke, T. H. Hubing |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 4 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 312 KB |
| Title: | A GPU Implementation of the 2-D Finite-Difference Time-Domain Code using High Level Shader Language |
| Abstract: | The authors have applied a graphics processing unit (GPU) to the finite-difference timedomain (FDTD) method to realize a cost-effective and high-speed computation of an FDTD simulation. The authors used the plane wave scattering by a perfectly conducting rectangular cylinder as the model and investigated the performance of this implementation. The authors timed the computation time of the scattered electromagnetic field by the two-dimensional (2-D) FDTD method at 1,000 steps. Using a PC equipped with an Intel 3.4-GHz Pentium 4 processor and an nVIDIA Geforce 7800 GTX GPU, the authors achieved an approximately 10-fold improvement in computation speed compared with the speed of a conventional central processing unit (CPU) executing the same task. |
| Author(s): | N. Takada, N. Masuda, T. Tanaka, Y. Abe, T. Ito, N. Takada, N. Masuda, T. Tanaka, Y. Abe, T. Ito |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 4 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 356 KB |
| Title: | EM Scattering from Bodies of Revolution using the Locally Corrected Nystrom Method |
| Abstract: | The locally corrected Nystr¨om method is applied to the magnetic field integral equation for a conducting body of revolution. A construction method is presented for the locally corrected weights for the resulting one-dimensional coupled scalar magnetic field integral equations. Special attention is paid to minimizing the cost for multi-frequency computations. Numerical results are presented for the sphere, oblate spheroid, and right circular cylinder. Good agreement with results from mature moment method codes is observed. |
| Author(s): | A. W. Wood, J. L. Fleming, A. W. Wood, J. L. Fleming |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 4 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 649 KB |
| Title: | Numerical Solution of Electromagnetic Scattering by Multiple Cylinders |
| Abstract: | A numerical solution based on integral equation is derived for an electromagnetic scattering from M multiple parallel cylinders. The problem is twodimensional and the integral equation is solved using the Nystr¨om method. To validate the algorithm, we compare our numerical results with the semi-analytical ones obtained from multipole expansion method. |
| Author(s): | F. Seydou, R. Duraiswami, T. Seppanen, F. Seydou, R. Duraiswami, T. Seppanen |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 4 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 393 KB |
| Title: | Design of a Near Field Protective Dielectric Radome “Window” for a Curved Phased Array Antenna-Axial Polarization Case |
| Abstract: | A systematic design method of near field dielectric windows for 2D conformal fed arrays was previously developed. This developed design yielded simultaneously well-behaved element patterns in both axial and circumferential polarization. The method includes dimensioning of the window thickness to maximize the radial decay rate of the radome induced surface waves, followed by inclusion of a sufficiently large gap to decouple the surface waves from the array face. This methodology has been successfully extended to 3D with circumferential polarization according to the previously established guidelines and has provided smooth patterns in the circumferential plane, but limited the scan in the axial plane. Here we will investigate the case with axial polarization and compare the available useful scan volume to that of circumferentially polarized excitation. |
| Author(s): | A. E. Fathy, A. E. Fathy |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 4 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 942 KB |
| Title: | Design, Modelling, and Synthesis of Radiation Pattern of Intelligent Antenna by Artificial Neural Networks |
| Abstract: | The work presented in this paper refers to the synthesis of the radiation pattern of intelligent antennas by the artificial neural networks (ANN) based on linear antennas array supplied with coaxial lines. The method of synthesis implemented for this type of antennas makes it possible to approach with an optimal desired radiation pattern specified by a gauge with modifying amplitude, phase excitation and sources space distribution. The approach used is based on geometry of the antennas and the artificial neural networks (ANN) which are able to model the linear antennas array. Our principal contribution in this paper is the extension of a synthesis model of the radiation pattern. The developed synthesis is based on the neural networks technique. |
| Author(s): | R. Ghayoula, N. Fadlallah, A. Gharsallah, M. Rammal, R. Ghayoula, N. Fadlallah, A. Gharsallah, M. Rammal |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 4 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 549 KB |
| Title: | Optimised Design of a Printed Elliptical Spiral Antenna with a Dielectric Superstrate |
| Abstract: | An elliptical spiral antenna embedded between a grounded dielectric substrate and superstrate is designed using a curved segment moment method employing complex images, which is driven by a marginal distribution optimisation algorithm. The spiral parameters together with substrate and superstrate permittivity and thickness values are optimised for low axial ratio and maximum gain and bandwidth. It is shown that the superstrate improves the bandwidth of the spiral. |
| Author(s): | S. K. Khamas, G. G. Cook, S. K. Khamas, G. G. Cook |
| File Type: | Journal Paper |
| Issue: | Volume: 23 Number: 4 Year: 2008 |
| Download Link: | Click here to download PDF File Size: 292 KB |