Electromagnetic wave scattering from an impedance plane covered with a dielectric layer

The problem of a plane wave scattering from an inhomogeneous periodic impedance plane, which is covered with a homogeneous layer of lossy dielectric, is solved in rigorous formulation. The solution is obtained in closed analytical form. The wave is scattered from a plane with non-specular reflecting reactance produced by the periodic groove structure. The grooves are filled with a low-loss dielectric and covered with a uniform dielectric layer.