EM scattering from edges in artificially hard and soft surfaces illuminated at oblique incidence

A canonical problem of remarkable importance for applications in the framework of high-frequency techniques is the diffraction from a wedge with arbitrary anisotropic impedance boundary conditions (IBCs) on its faces. At oblique incidence, the above scattering problem has not yet been solved analytically for the most general configurations. This paper provides uniform diffraction coefficients for those anisotropic impedance wedge configurations for which exact integral representations for the field are presently available. The specific class of anisotropic IBCs considered for the wedge faces is characterized by a surface impedance tensor with its principal axes parallel and perpendicular to the edge and exhibiting a vanishing surface impedance in one of the principal directions. Such an impedance tensor is suitable to simulate the behavior of artificially hard and soft surfaces, that are usually realized by means of dielectric filled corrugations in metallic surfaces or strip-loaded grounded dielectric slabs.