Image theory for the soft and hard surface

Image theory is developed for sources above a planar anisotropic boundary surface, often labeled as soft and hard surface. Realizable with tuned corrugations so that the electric and magnetic field components along the corrugations become zero. The idea pursued is to decompose the original source in two components, giving rise to fields TE and TM to the direction of corrugation, respectively. This makes the problem split into two parts for which the image sources can be easily constructed. For an electric dipole, the image turns out to consist of a rotated dipole in the mirror image point plus a transmission-line current source parallel to the corrugations. The theory is readily applicable to various microwave problems involving a planar soft and hard surface