Scattering from coated cracks for sub-millimeter wave applications by KP method

The Kobayashi Potential (KP) is an analytical technique used for solving mixed boundary geometrical problems. In this paper scattering by a 2D dielectric filled rectangular crack on a ground plane, coated by a dielectric layer for TM case is studied using KP method. The fields in three distinctive regions of the geometry are expressed in terms of Bessel eigenfunctions. The problem is reduced to a system of equations involving summations with an infinite number of unknown coefficients. By applying Weber-Schafheitlin discontinuous integrals, the summations truncated with high numerical accuracy. We employ finite element method (FEM) for validation of our method. Finally, the influence of coating dielectric layer is investigated on the scattered field. This technique could open practical means for non destructive testing in Terahertz frequency region.