High-frequency scattering by the edge of a thin dielectric slab loaded by a metallic strip grating

A heuristic diffraction coefficient is presented that is suitable to describe the scattering from the edge of a thin dielectric half-plane, loaded by a metallic strip grating on one of its faces, when the grating period is much smaller than the free-space wavelength. The most general case of oblique incidence is analysed, with the incident plane wave arbitrarily polarised. The direction of the strips can be arbitrarily oriented with respect to the edge of the half-plane. Extensive numerical tests have been performed to verify the effectiveness of the heuristic solution and to check its accuracy through comparisons with reference data