TE Wave Excitation and Scattering by Obstacles in Guiding and Surround Regions of Asymmetric Planar Dielectric Waveguide

Abstract

Scattering of bound surface waves by dielectric obstacles along planar dielectric waveguide is studied. An asymmetric planar dielectric waveguide is formed by the tri-layered substrate/film/cover environment, typical of integrated circuits for millimeter and optical wavelengths. An electric Green's function (believed new) is constructed for the TE field maintained in either the film or cover layers by currents immersed in those regions. Using a direct complex analysis approach, the Green's function is expanded in the discrete and continuous propagation spectrum components for the asymmetric planar waveguide. This electric Green's function is exploited to study scattering of TE surface waves by uniform dielectric discontinuity placed arbitrarily along the asymmetric waveguide. A polarization EFIE description of the discontinuity region is developed. Scattering coefficients are subsequently calculated in terms of the induced field. Method of moment (MOM) numerical solutions are implemented for slice discontinuities along an asymmetric slab waveguide.