A well‐conditioned integral equation for electromagnetic scattering from composite inhomogeneous bi‐anisotropic material and closed perfect electric conductor objects

Abstract

A well‐conditioned volume‐surface integral equation, called the volume integral equation‐ combined field integral equation, is applied to analyse electromagnetic (EM) scattering from arbitrarily shaped three‐dimensional composite objects comprising both inhomogeneous bi‐anisotropic material and closed perfect electric conductors (PECs). The equivalent surface and volume currents are respectively expanded using the commonly used RWG and SWG basis functions, while a matrix equation is derived by the method of moments. Because the magnetic field integral equation is involved in modelling the surface electric current, and the constitutive parameters are all tensors, some new kinds of singularities are encountered and properly handled in the filling process of the impedance matrix. Several numerical results of EM scattering from composite bi‐anisotropy and closed PEC objects are shown to illustrate the accuracy and efficiency of the proposed scheme. The validity of the continuity condition of electric flux enforced on the bi‐anisotropy‐PEC interfaces, which can be used to eliminate the volumetric electric unknowns, is also verified. Disciplines Electrical and Computer Engineering | Signal Processing Comments This is the published version of the following article: Liu, Jinbo, Jin Yuan, Zengrui Li, and Jiming Song. A well‐conditioned integral equation for electromagnetic scattering from composite inhomogeneous bi‐anisotropic material and closed perfect electric conductor objects. IET Microwaves, Antennas & Propagation (2021). DOI: 10.1049/mia2.12051. Posted with permission. Creative Commons License This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License This article is available at Iowa State University Digital Repository: https://lib.dr.iastate.edu/ece_pubs/302 Received: 3 November 2020 Revised: 12 January 2021 Accepted: 13 January 2021 IET Microwaves, Antennas & Propagation DOI: 10.1049/mia2.12051 OR I G INAL RE SEARCH PA PER A well‐conditioned integral equation for electromagnetic scattering from composite inhomogeneous bi‐anisotropic material and closed perfect electric conductor objects Jinbo Liu | Jin Yuan | Zengrui Li | Jiming Song State Key Laboratory of Media Convergence and Communication, Communication University of China, Beijing, China School of Information and Communication University, Communication University of China, Beijing, China Electrical and Computer Engineering, Iowa State University, Ames, Iowa, USA Correspondence Zengrui Li, Chaoyang District, Beijing, China, 100024. Email: [email protected] Funding information Fundamental Research Funds for the Central Universities, Grant/Award Number: CUC19ZD001; National Natural Science Foundation of China, Grant/Award Numbers: 61701447, 61971384, 62071436 Abstract A well‐conditioned volume‐surface integral equation, called the volume integral equation‐ combined field integral equation, is applied to analyse electromagnetic (EM) scattering from arbitrarily shaped three‐dimensional composite objects comprising both inhomogeneous bi‐anisotropic material and closed perfect electric conductors (PECs). The equivalent surface and volume currents are respectively expanded using the commonly used RWG and SWG basis functions, while a matrix equation is derived by the method of moments. Because the magnetic field integral equation is involved in modelling the surface electric current, and the constitutive parameters are all tensors, some new kinds of singularities are encountered and properly handled in the filling process of the impedance matrix. Several numerical results of EM scattering from composite bi‐anisotropy and closed PEC objects are shown to illustrate the accuracy and efficiency of the proposed scheme. The validity of the continuity condition of electric flux enforced on the bi‐anisotropy‐PEC interfaces, which can be used to eliminate the volumetric electric unknowns, is also verified.