The surface impedance of metallic objects: rigorous calculations for imperfectly conducting diffraction gratings

An accurate computation of the surface impedance of highly conducting metallic gratings is presented. A rigorous electromagnetic formalism is used for solving for the fields at the grating boundary. The influence of the local curvature of the grating profile, the refractive index of the metal, and the angle of incidence are studied. Particular attention is given to the comparison between the efficiencies obtained using the rigorous method and those obtained assuming that the surface impedance is a constant.<
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