Analytical Explanation of Electromagnetic Diffraction From Double-layered Dielectric Wedge

This article explains the phenomenon of electromagnetic diffraction from a double-layered dielectric wedge analytically. Mountain ridges with forest or snow cover, concrete building with wooden interior wall decoration or vertical garden, et cetera are good examples of double-layered dielectric wedges that often appear in indoor and outdoor propagation channel models. The analytical model presented here considers the contributions from the inner and outer wedges individually. Then the total diffracted field is calculated by superimposing one upon another. The problem becomes complex because the field diffracted from the inner wedge has a cylindrical wavefront, which gets the chance to reach air only after transmitting through the outer wedge’s dielectric material. Moreover, since the interface between air and the outer wedge dielectric is not planar, it adds to the complexity of the problem. The proposed analytical model has been validated by comparing its results with the results from finite-difference time-domain (FDTD) simulations.