Scattering by anisotropic surfaces

Two types of anisotropic surfaces have been studied: the unidirectionally conducting (UEC) surface and the strip grating (SG) surface. The UEC surface is an idealised homogenous model of the SG surface. The plane wave scattering from a UEC strip has been analysed employing different approximate techniques such as Physical Optics, Physical Theory of Diffraction and Geometrical Theory of Diffraction. These techniques are all based on the exact analytical solution for the UEC half-plane problem established by Lumholt and account for different scattering mechanisms such as first-order edge diffraction, second-order edge diffraction and surface wave diffraction. The accuracy of the different approximate techniques was determined through comparisons with integral equation (IE) results. The plane wave scattering from the SG surface has been analysed employing both an approximate analytical model and an integral equation approach. Numerous comparisons between the two types of surfaces were carried out to investigate under which conditions the UEC surface provides an accurate model for the SG surfaces. These conditions were quantified in terms of periodicity of the SG surface and the frequency, polarisation and direction of propagation of the incident plane wave.