Diffraction of a TM whispering gallery mode by the edge of a nonperfectly conducting spherically curved sheet

Electromagnetic scattering is a function of the scatterer´s material properties as well as its geometry. Therefore, it is necessary to examine the effect of the physical properties of a body on diffraction phenomena besides the geometrical properties. The aim here is to give a rigorous asymptotic solution for the diffraction of high-frequency electromagnetic fields by an edge on a spherically curved sheet having a particular impedance property. The solution is interpreted with the terminology of the geometrical theory of diffraction (GTD).