A Study of Uniform Approximation of Plane Gratings by Oblique Incidence

Abstract

Plane gratings with small periodicity must be approximated by equivalent surface resistive sheet. In this paper, uniform approximation of equivalent surface resistance is considered for electromagnetic scattering problem of plane gratings by circularly polarized incidence. By investigating the difference between the equivalent surface resistance and the numerical values corresponding to surface resistance of plane gratings, the applicable condition of the uniform approximation is directly cleared.