Scattering analysis of arbitrarily shaped 3-D PEC bodies inserted above or below flat and lossy half-spaces by current decomposition method

This paper presents a method for modifying surface integral equations (SIEs) to address scattering problems of PEC targets above or below flat dielectric surfaces. This method decomposes the surface current densities on an infinitely long flat interface into two parts. The first part represents the induced current in the absence of the target, whereas the second part represents the perturbation current on a finite partition of the infinite surface. This method enables a more precise analysis of the current distribution on the surface. Additionally, it assumes that perturbation currents have negligible amplitude when far away from the target object. For this purpose, the PMCHWT (Poggio–Miller–Chang–Harrington–Wu-Tsai) formulation is employed for the dielectric interface, and the current on the PEC target is formulated with the EFIE (Electric Field Integral Equation). Then, the method of moments (MoM) is used to solve the resulting SIEs, while well-known RWG (Rao-Wilton-Glisson) basis functions are exploited for discretization. Besides, the proposed approach is compared and proven against image theory, commercial EM solver, and literature studies.