Some diffraction patterns of an absorbing half-plane

Abstract

Far-field diffraction patterns are presented for the two-dimensional electromagnetic problem of plane wave scattering by a half-plane with a constant surface impedance. Previous results have been mainly concerned with a small surface impedance. In contrast with this, our diffraction patterns have been computed for the relatively arbitrary impedance of a half-plane which acts like a black screen for a prescribed angle of plane wave incidence. Such a half-plane may produce no reflected plane wave. Numerical calculations for the far fields show that the back-scattered fields are more noticeably influenced by the surface impedance than the forward-scattered fields. Nulls are found in the back-scattered fields. This type of black screen produces approximately the same scattering as the Sommerfeld black screen. Simple qualitative estimates of the diffracted far fields may be made without elaborate calculations.