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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.


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Journal ArticleDOI
01 Feb 2013
TL;DR: The application of the newly developed integral equation domain decomposition method (IE-DDM) to compute the plane-wave scattering from the jet aircraft, however with neither dielectrics nor lossy thin coatings.
Abstract: In this paper, we present our efforts in combating a challenging large multiscale electromagnetic scattering problem, viz. a plane-wave scattering from a mockup partially coated composite jet aircraft at X-band. We first summarize the application of the newly developed integral equation domain decomposition method (IE-DDM) to compute the plane-wave scattering from the jet aircraft, however with neither dielectrics nor lossy thin coatings. We proceed to compute the scattering from the aircraft with dielectrics and lossy thin coatings by employing two additional computational electromagnetics (CEM) techniques: a generalized combined field integral equation (G-CFIE) method to calculate electromagnetics (EM) scatterings from penetrable dielectric targets, and a hybrid finite elements and boundary elements method tailored specifically to address perfect electric conductor (PEC) targets partially coated with lossy thin materials.

77 citations

Journal ArticleDOI
TL;DR: In this article, a system of 3N linear simultaneous equations is derived from which the scattering properties of an assembly of N spheres can be obtained, except that the individual spheres must satisfy the criteria for the Rayleigh approximation, they may be of arbitrary volume and complex refractive index.
Abstract: A system of 3N linear simultaneous equations is derived from which the scattering properties of an assembly of N spheres can be obtained. Except that the individual spheres must satisfy the criteria for the Rayleigh approximation, they may be of arbitrary volume and complex refractive index. The results of numerical calculations are presented illustrating the properties of the scattered light, and comparisons are made with previous work. A diagnostic technique is proposed which should be capable of determining the size and complex refractive index of the spheres and the number of particles in a long chain agglomerate.

77 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigated the low-frequency behavior of the PEEC matrix and demonstrated that the system matrix is well behaved from a full-wave solution at high frequencies to a pure resistive circuit solution at dc, thereby enabling dc-to-daylight simulations.
Abstract: The partial element equivalent circuit (PEEC) formulation is an integral equation based approach for the solution of combined electromagnetic and circuit (EM-CKT) problems. In this paper, the low-frequency behavior of the PEEC matrix is investigated. Traditional EM solution methods, like the method of moments, suffer from singularity of the system matrix due to the decoupling of the charge and currents at low frequencies. Remedial techniques for this problem, like loop-star decomposition, require detection of loops and therefore present a complicated problem with nonlinear time scaling for practical geometries with holes and handles. Furthermore, for an adaptive mesh of an electrically large structure, the low-frequency problem may still occur at certain finely meshed regions. A widespread application of loop-star basis functions for the entire mesh is counterproductive to the matrix conditioning. Therefore, it is necessary to preidentify regions of low-frequency ill conditioning, which in itself represents a complex problem. In contrast, the charge and current basis functions are separated in the PEEC formulation and the system matrix is formulated accordingly. The incorporation of the resistive loss (R) for conductors and dielectric loss (G) for the surrounding medium leads to better system matrix conditioning throughout the entire frequency spectrum, and it also leads to a clean dc solution. We demonstrate that the system matrix is well behaved from a full-wave solution at high frequencies to a pure resistive circuit solution at dc, thereby enabling dc-to-daylight simulations. Finally, these techniques are applied to remedy the low-frequency conditioning of the electric field integral equation matrix

77 citations

Journal ArticleDOI
TL;DR: In this paper, a novel algorithm for efficient estimation of objective function sensitivities for time-domain transmission-line modeling (TLM) with nondispersive boundaries is presented, which is illustrated through the estimation of the sensitivities of objective functions with respect to the dimensions of waveguide discontinuities.
Abstract: We present a novel algorithm for efficient estimation of objective function sensitivities for time-domain transmission-line modeling (TLM) with nondispersive boundaries. The original electromagnetic structure is simulated using TLM. An adjoint TLM simulation that runs backward in time is derived and solved. The sensitivities of the objective function with respect to all designable parameters are estimated using only the original and adjoint simulations. Our approach is illustrated through the estimation of the sensitivities of objective functions with respect to the dimensions of waveguide discontinuities. A very good match is obtained between our sensitivity estimates and those obtained through the accurate and time-intensive central difference approximation.

77 citations

Journal ArticleDOI
TL;DR: In this article, a p-type multiplicative Schwarz (pMUS) method was proposed for solving three-dimensional waveguide discontinuity problems, which used hierarchical curl-conforming basis functions that incorporated a discrete Hodge decomposition explicitly and treated each polynomial space as an abstract grid/domain in the Schwarz method.
Abstract: This paper presents the application of a p-type multiplicative Schwarz (pMUS) method for solving three-dimensional waveguide discontinuity problems. The two major contributions of the proposed pMUS method are: 1) the use of hierarchical curl-conforming basis functions that incorporate a discrete Hodge decomposition explicitly and 2) the treatment of each polynomial space (or basis functions group) as an abstract grid/domain in the Schwarz method. These two features greatly improve the applicability of the curl-conforming vector finite-element methods (FEMs) for solving Maxwell equations. Various numerical examples are solved using the proposed approach. The performance of the pMUS method has been compared to commercial FEM software as well as the incomplete Choleski conjugate gradient method. It is found that the pMUS method exhibits superior efficiency and consumes far less memory and CPU times.

77 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202325
2022101
2021153
202091
2019109
2018107