High-frequency scattering from anisotropic impedance wedges at oblique incidence

An exact integral representation for electromagnetic scattering from a wedge with isotropic impedance faces, illuminated at normal incidence by a plane wave, has been given by Malyuzhinets (1958). Spectral integral solutions have also been obtained for some special wedge configurations in the more general case of skew incidence. Moreover, a numerical solution, based on the parabolic equation method, has been derived for more general configurations. The paper presents an approximate analytical solution for the analysis of plane wave diffraction from an anisotropic impedance wedge with an arbitrary exterior angle at skew incidence. The method proposed is an extension of the perturbative procedure. Preliminary numerical results for the anisotropic wedge problem, obtained by the application of this technique, are presented and compared with reference solutions available in the literature and with data derived by extending the parabolic model proposed by Pelosi, Selleri and Graglia (see IEEE Trans. Antennas Propagat., vol.AP-44, no.2, 1996). Finally, it is worth observing that this solution contains as a limit the case of the isotropic impedance wedge as well, extending previous analytic solutions for three-dimensional electromagnetic scattering to more general configurations with arbitrary impedance faces and arbitrary wedge angles.