A General Solution to the Scattering of Electromagnetic Waves from a Strip Grating

Abstract

We describe a new robust approach for the analysis of strip gratings, both of finite and infinite conductivity, for the TE and TM cases. The field distributions in the plane of the grating are expanded in a Fourier series, whose coefficients are derived as the solution to an infinite-dimensional system of linear equations. Various configurations of the scatterer are considered and it is shown that even in cases where the Tsao-Mittra SIT procedures fails to converge and the moment method requires a large matrix to arrive at a solution, our method yields reasonable results even for small matrix sizes. The accuracy of the solution procedure is analysed by considering the mean-square error in the field magnitudes as a function of the truncation size of the infinite system of linear equations.