Synthesis of directional couplers based on ridged waveguides coupled by a system of circular apertures

A technique of electrodynamic analysis and synthesis of directional couplers based on Π-shaaped waveguides with a system of small coupling apertures is reported. Parameters of coupling between two waveguides through a small aperture are calculated within quasi-static Bethe’s theory. Critical wavenumbers and components of the electromagnetic fields of ridged waveguides are calculated with allowance for the features of the electromagnetic field on the edge. The characteristics of synthesized directional couplers based on Π-shaped waveguides with coupling along the wide wall of 20 and 10 dB are reported.