EFFECTIVENESS OF RESISTIVE BOUNDARY-CONDITIONS FOR PLANE GRATINGS

The spectral Galerkin procedure is often used to analyze scattering by metallic gratings. The resistive boundary condition is applied to met allic gratings that are assumed to be zero-thickness plane gratings. H owever, it is difficult to simulate plane gratings without knowing the limits of thickness in the application of such boundary conditions. I n this report, the relations between a plane metallic grating and a th in dielectric grating with complex permittivity are investigated by us ing the conventional method for dielectric gratings. From numerical re sults, the effectiveness of resistive boundary conditions is discussed . (C) 1998 Scripta Technica.