H-Polarized Wave Diffraction by Two Layers of Semi-Infinite Strip Gratings

This study investigates the diffraction of a plane H-polarized electromagnetic wave by a dual-layered grating. Each layer is composed of a semi-infinite array of infinitely thin, perfectly electric conducting (PEC) strips. The expression for the scattered field is formulated as a superposition of the field from an infinite perfectly periodic grating and a correction field. Both components are derived from a set of hypersingular integral equations, which are solved using a Nyström-type discretization scheme.