Computational electromagnetics

About: Computational electromagnetics is a research topic. Over the lifetime, 6412 publications have been published within this topic receiving 113727 citations. The topic is also known as: Electromagnetic field analysis.

Broadband Müller-MLFMA for Electromagnetic Scattering by Dielectric Objects

Abstract: The multilevel fast multipole algorithm (MLFMA) is very efficient for solving large-scale electromagnetic scattering problems. However, at low frequencies, or when the discretization is small compared with the wavelength, both the MLFMA and the underlying integral equation formulation typically suffer from a subwavelength breakdown. For the electromagnetic scattering from a homogeneous dielectric object, we obtain a stable and well-conditioned surface integral formulation using a variant of the classical Muumlller formulation and linear basis functions. To overcome the subwavelength breakdown of the MLFMA, we use both propagating and evanescent plane waves to represent the fields. The implementation is based on a combination of the spectral representation of the Green's function and Rokhlin's translation formula. We also present a new interpolation scheme for the evanescent part, which significantly improves the error-controllability of the MLFMA-implementation. Several numerical results verify both the error-controllability and scalability of the proposed algorithm

Application of the Random Coupling Model to Electromagnetic Statistics in Complex Enclosures

Abstract: The effectiveness of the random coupling model (RCM) in predicting electromagnetic wave coupling to targeted electronic components within a complex enclosure is examined. In the short-wavelength limit with respect to the characteristic length of the enclosure, electromagnetic wave propagation within a large enclosure is sensitive to small changes to the interior, or to the boundaries of the enclosure. Such changes can reduce or invalidate the applicability of deterministic predictions of the electromagnetic fields at radiofrequencies (RF) in large enclosures. Under such circumstances, a statistical approach is needed to provide a better understanding of RF coupling to components within large enclosures. In this paper, we experimentally demonstrate the applicability of a statistical technique, the RCM, to estimate the probabilistic magnitudes of RF fields on electrically large components (i.e., long cables, etc.) that are partially shielded within a complex, 3-D enclosure.

The ICVSIE: A General Purpose Integral Equation Method for Bio-Electromagnetic Analysis

Abstract: Objective: An internally combined volume surface integral equation (ICVSIE) for analyzing electromagnetic (EM) interactions with biological tissue and wide ranging diagnostic, therapeutic, and research applications, is proposed Method: The ICVSIE is a system of integral equations in terms of volume and surface equivalent currents in biological tissue subject to fields produced by externally or internally positioned devices The system is created by using equivalence principles and solved numerically; the resulting current values are used to evaluate scattered and total electric fields, specific absorption rates, and related quantities Results: The validity, applicability, and efficiency of the ICVSIE are demonstrated by EM analysis of transcranial magnetic stimulation, magnetic resonance imaging, and neuromuscular electrical stimulation Conclusion: Unlike previous integral equations, the ICVSIE is stable regardless of the electric permittivities of the tissue or frequency of operation, providing an application-agnostic computational framework for EM-biomedical analysis Significance: Use of the general purpose and robust ICVSIE permits streamlining the development, deployment, and safety analysis of EM-biomedical technologies

An hp-adaptive finite element method for scattering problems in computational electromagnetics

Abstract: An hp-adaptive finite element (FE) approach is presented for a reliable, efficient and accurate solution of 3D electromagnetic scattering problems. The radiation condition in the far field is satisfied automatically by approximation with infinite elements (IE). Near optimal discretizations that can effectively resolve local rapid variations in the scattered field are sought adaptively by mesh refinements blended with graded polynomial enrichments. The p-enrichments need not be spatially isotropic. The discretization error can be controlled by a self-adaptive process, which is driven by implicit or explicit a posteriori error estimates. The error may be estimated in the energy norm or in a quantity of interest. A radar cross section (RCS) related linear functional is used in the latter case. Adaptively constructed solutions are compared to pure uniform p approximations. Numerical, highly accurate, and fairly converged solutions for a number of generic problems are given and compared to previously published results. Copyright © 2004 John Wiley & Sons, Ltd.

A quasi three-dimensional distributed electromagnetic model for complex power distribution networks

Abstract: This paper describes a systematic methodology for the electromagnetic modeling of complex power distribution networks. The proposed methodology uses locally three-dimensional modifications to an otherwise two-dimensional description of the behavior of electromagnetic fields between power/ground plane pairs, to model correctly the field behavior at discontinuities such as vias, pins, as well as splits in the power/ground plane structure. Furthermore, a systematic synthesis methodology is presented for the direct generation of a SPICE-compatible multi-port macro-model for the power distribution network from its discrete quasi three-dimensional model. The proposed modeling and equivalent circuit synthesis methodologies are validated through a specific numerical simulation study of the transient electromagnetic analysis of a power/ground plane pair during switching.