Surface Integral Equation Method for Generalized Soft-and-Hard Boundary Condition

A surface integral equation (SIE) method is developed for analyzing electromagnetic scattering by objects with generalized soft-and-hard (GSH) boundary conditions. GSH boundary condition is an anisotropic impedance boundary condition, which limits the tangential electric and magnetic fields in specified directions. In the developed SIE formulation, the GSH boundary condition is expressed in a vector form with two sets of orthogonal vectors, which can be combined with the field integral equations. The resulting equation can be discretized with the standard method of moments (MoM) using triangular elements and the Rao-Wilton-Glisson (RWG) functions. By varying the GSH condition the direction of the tangential electric and magnetic fields on the surface can be flexibly changed.