A Modified Dielectric Contrast based Integral Equation for 2D TE Scattering by Inhomogeneous Domains

Abstract: This work presents a modified domain integral equation approach for the forward problem of TE scattering, employing a modified definition of dielectric contrast and discretizing the electric field density using Rao-Wilton-Glisson (RWG) basis functions. The proposed formulation mitigates the numerical challenges introduced by the gradient-divergence operator in traditional electric field-based vector formulations. The use of RWG basis functions over triangular meshes enhances geometric conformity, ensures tangential continuity across dielectric interfaces, and facilitates the application of well known singularity extraction techniques for numerical accuracy. Validation through numerical experiments on a two-layered dielectric cylinder demonstrates excellent agreement between computed and analytical scattered fields. Convergence studies confirm improving solution accuracy with mesh refinement indicating robustness with respect to discretization without increasing the iterations.