Electromagnetic wave scattering by a plane metallic grating loaded with three dielectric layers

Abstract

AbstractIn this paper, electromagnetic wave scattering by a plane metallic grating loaded with three dielectric layers is precisely analyzed by use of a new type of spectral domain method combined with the sampling theorem. Two different polarizations, E‐ and H‐waves, are considered here. Induced surface currents on the conducting strips are expanded in terms of weighted Fourier series taking into account the field singularity near an edge and spectral expressions for the scattered fields are given. Then the unknown coefficients related to surface current expansions are solved in spectral domain by imposing the boundary condition associated with a conducting strip. Accuracy of the numerical results is checked in comparison with extrapolated values, and numerical calculations are carried out for frequency characteristics of reflectivity and transmittivity as well as surface current distributions. Insertion loss of dielectric layers is also described in connection with a polarization discriminator of antennas. Although we cannot compare the numerical results with the rigorous ones as in the case of no dielectric loading, it seems that the present numerical results are considerably good.