Efficient Nyström Solutions of Electromagnetic Scattering by Composite Objects With Inhomogeneous Anisotropic Media

Analysis of electromagnetic (EM) scattering by composite objects with inhomogeneous or anisotropic media requires an efficient solution of volume integral equations (VIEs) or volume-surface integral equations (VSIEs) in the integral equation approach. The traditional method of moments (MoM) with the Rao-Wilton-Glisson (RWG) basis function and the Schaubert-Wilton-Glisson (SWG) basis function may not be convenient because the basis functions are defined over a triangular or tetrahedral element pairs and the SWG basis function could cause a surface charge density on the common faces separating dissimilar media. In this work, we develop an efficient Nyström scheme as an alternative to solve the VIEs or VSIEs for those objects. The advantages of Nyström method include the simple mechanism of implementation, allowance of nonconforming meshes, and removal of basis or testing function, making the method more suitable for solving such problems. Numerical examples for EM scattering by typical objects are presented to demonstrate the method.