Scattering of modes by the end of a diaphragm-loaded planar dielectric waveguide

A planar dielectric waveguide loaded with an infinitely thin perfectly conducting diaphragm is considered. The problem of the guided mode reflection from the end of such a waveguide is analyzed with the help of the integral equation method and the variational method. Dependences of the fundamental mode reflection coefficient on the waveguide parameters and on the dimension of the aperture are calculated.