International Journal of Applied Electromagnetics and Mechanics - Volume 55, issue 1

Authors: Liao, Y.-H. | Zhu, H.-C. | Huang, K.-M.

Article Type: Research Article

Abstract: In this paper, an efficient finite element method (FEM) in solving electromagnetic scattering from body coated by thin-layer materials based on nonlinear coordinate transformation is presented. To solve scattering thin-layer material problems accurately, the traditional FEM employs rigor meshes to discretize the thin-layer structure resulting in numerous meshes, unknowns and ill-conditioned matrices. It requires much expensive storage and computational time. The proposed approach employing nonlinear coordinate transformation maps the dense thin-layer geometry space into a sparse space. In this manner, the need of rigor local mesh refinement can be eliminated. Thus, it provides an efficient approach to compute scattering from …body coated by thin-layer materials. Two examples validate the efficiency and accuracy of the proposed method. Show more

Keywords: Thin-layer materials, efficient FEM, electromagnetic scattering, nonlinear coordinate transformation, constitution relationship

DOI: 10.3233/JAE-170028

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 55, no. 1, pp. 139-150, 2017

Authors: Santos, Kenedy Marconi G. | Novo, Marcela Silva | Fontgalland, Glauco | Perotoni, Marcelo Bender

Article Type: Research Article

Abstract: This paper presents a simple methodology to measure the shielding quality in coaxial cables and connectors through the Shielding Effectiveness (SE) parameter at high frequencies. The discovery of complications as soon as possible is of paramount importance in order to avoid unpredicted costs in advanced phases of the project. This proposal describes an SE measurement setup using standard Electromagnetic Compatibility instrumentation such as electric field probe, signal generator, and power meter in a semi-anechoic shielded chamber and comparing physical measurement with computational simulations. A virtual model has been created based upon the physical coaxial cable, respecting dimensions and materials characteristics. …The agreement between measurements and simulations is good in the considered frequency range 240 MHz to 3 GHz. Show more

Keywords: Electric field, shielding effectiveness, coaxial cable, connectors

DOI: 10.3233/JAE-170032

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 55, no. 1, pp. 151-166, 2017

Authors: Jiang, Zhaoneng | Zhang, Qingchun | Zha, Liping | Yang, Xiaoyu

Article Type: Research Article

Abstract: For the electrically large problems, the discrete unknowns of surface integral equation are very large, resulting in the matrix condition is relatively poor. The high order hierarchical basis functions are utilized to reduce the discrete unknowns, thereby reducing the memory consumption and computation time. Meanwhile, modified multilevel compressed block decomposition (MMLCBD) is applied to accelerate the matrix-vector multiplication operations, which utilizes novel technique to improve the solving efficiency by combining a less accurate truncating threshold in MLCBD with a rapid and cheap iterative refinement process. Combining the high order hierarchical basis functions with MMLCBD can make good use of their …respective advantages to analyze the large-scale electromagnetic problems efficiently. The numerical results demonstrate that the proposed method is much more efficient than conventional MLCBD for analyzing the large-scale electromagnetic problems. Show more

Keywords: Multilevel compressed block decomposition (MLCBD), high order hierarchical basis functions, direct solution

DOI: 10.3233/JAE-170035

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 55, no. 1, pp. 167-175, 2017

Authors: Codecasa, Lorenzo | Di Rienzo, Luca

Article Type: Research Article

Abstract: An approach to quantify uncertainty in linear three-dimensional magnetostatic problems with correlated random reluctivities is proposed. Such strategy is based on a reduced-order model and a spectral approximation of the deterministic parametric magnetostatic problem for accurately and efficiently estimating the statistics of the quantities of interest.

Keywords: Uncertainty quantification, magnetostatics, finite integration technique

DOI: 10.3233/JAE-170063

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 55, no. 1, pp. 177-183, 2017