Solution of Volume Integral Equation Using the Edge-MB Basis Functions for Inhomogeneous Dielectric Objects

This letter proposes a volume integral equation (VIE) scheme with reduced unknowns for analyzing electromagnetic scattering from complex inhomogeneous dielectric objects. This scheme utilizes a novel edge basis for the multibranch Schaubert-Wilton-Glisson function (EDGE-MB). The problem of over-mesh and increased unknowns is severe for high-contrast media and multi-domain structures. In the proposed scheme, the divergence-free condition is applied to the multibranch Schaubert–Wilton–Glisson (MB-SWG) basis function, and we use an EDGE-MB basis function defined within boundary tetrahedral elements instead of SWG basis functions. At the same time, the calculation process of matrix elements with the EDGE-MB scheme is more efficient than traditional SWG-VIE or MB-VIE for multiboundary and multimedium problems. Finally, several numerical results are presented to demonstrate the accuracy and efficiency of the proposed method.