A New Analytical Model of Diffraction by 3D Dielectric Corners

We present a novel model of the dielectric cubic corner, that is suitable for inclusion in a standard electromagnetic (EM) simulator. The model starts from a consideration of the equivalent current densities on the cube facets. It proceeds by employing a classical multipole expansion of the Green's function at the corner and introduces the novel principle of simultaneous transverse resonance diffraction (STRD) in order to determine the order of singularity. The theory is validated by numerical simulations, yielding information about the accuracy of the near field around a 90 deg. dielectric corner.