UC Irvine

A closed form, high-frequency solution is presented for the scattering in the near zone by a semi-infinite thick screen, when it is illuminated by a line source at finite distance. This solution is derived for a thick screen with perfectly conducting side walls, and either perfectly conducting or artificially soft boundary condition on the top face joining the two wedges. This last condition is practically obtained by etching on this face a quarter of wavelength deep corrugations with a small periodicity with respect to the wavelength. Owing to the particular properties of the artificially soft surface, a strong decoupling effect in the shadow region is achieved for both polarizations; thus, an effective shielding from undesired interferences is obtained.