Coupling losses of rectangular waveguide resonator-angular-spectrum analysis

Considers the rectangular waveguide resonator in which a spherical mirror of radius R is positioned at a distance d from the waveguide end, which coincides with the plane z=0. The cross-section of the waveguide is 2ax2b. We assume that the electric field is x polarized, the EH/sub 11/-mode only exists in the waveguide when the field is polar in the direction x and the reflectivity of the mirror is 1. The results of computation show that for the rectangular waveguide resonator there only exist the configuration to provide low coupling losses corresponding to plane-parallel geometry. Comparison in terms of diffraction integral, calculation process is simplified and the results are more accurate.