Diffraction at edges in planar impedance surfaces: revisited exact solutions at skew incidence

In this paper, the revisited exact solutions are presented for the electromagnetic problems of a half plane with surface impedance faces and a surface impedance edge discontinuity on a plane, when they are illuminated at skew incidence. They are obtained by introducing a suitable new set of combined spectra that exhibit all the desired properties. As a consequence, the final expressions of the spectra satisfy all the Malyuzhinets method conditions, the edge conditions, explicitly satisfy reciprocity and nicely reduce to the original Malyuzhinets solution for normal incidence. The importance of the achieved symmetry with respect to incidence and observation aspects, is further emphasized in extending the solutions to dipole source illuminations.