Characterization of a resistive half plane over a resistive sheet

The diffraction by a resistive half plane vertically displaced from a uniform resistive sheet is considered. The corresponding exact diffraction coefficient is derived for this configuration with an H-polarized illumination using the dual integral equation method, following a development similar to that in Y. Sunahara and T. Sekiguchi (1981) and M. A. Ricoy and J. L. Volakis (1989). The encountered Wiener-Hopf split function is factorized via an efficient numerical procedure. When the separation between the resistive half plane and resistive sheet is on the order of a tenth of a wavelength or less, the structure is virtually planar. Thus, a simplified model of the original configuration is a single equivalent resistive half plane illuminated by a direct and an image wave. The equivalent resistivity is determined using an approximate image theory such that the geometrical-optics field of the original structure is preserved for all angles. The diffracted field of the model is in good agreement with the exact solution, which is in turn validated using a moment method solution.<>