An Entire Domain CFVIE-CDSE Method for EM Scattering on Electrically Large Highly Inhomogeneous Gyrotropic Circular Cylinders

Abstract

A coupled-field volume integral equation (CFVIE) method for electromagnetic (EM) scattering on electrically large, highly inhomogeneous gyrotropic circular cylinders, under normal incidence, is developed in this work. The CFVIEs are solved by the cylindrical Dini series expansion (CDSE) method where the unknown fields are expanded by entire domain orthogonal vectorial basis functions. The main advantage of the present method is that it permits the scatterer to have continuously varying highly inhomogeneous gyrotropic characteristics, i.e., the constitutive parameters of the cylinder can be highly inhomogeneous in both gyroelectric and gyromagnetic tensors. Initially, the 2-D Green's function (GF) is expanded in a tensorial form using the cylindrical vector wave functions (CVWFs). Then, by employing the CDSE for the unknown fields, the 2-D volumetric integrals are carried out analytically, reducing the CFVIEs to a set of algebraic equations. The method is validated by comparisons with the exact solution based on the separation of variables method (SVM) for homogeneous gyroelectric/gyromagnetic cylinders, with HFSS commercial software for three-layered gyroelectric cylinders, as well as with the recently developed hybrid projection method (HPM) for electrically large continuously varying highly inhomogeneous isotropic cylinders. Results for combined gyroelectric-continuously varying highly inhomogeneous isotropic cylinders are presented and discussed.