Synthesis of Elliptic Filter on Complex Resonant Diaphragms in Rectangular Waveguide

The synthesis of waveguide band-pass elliptical filters is realized. The thin transverse resonance diaphragms with an aperture in the form of a rectangular window with two metal L-shaped ridges are used as resonators of the filter. The electrodynamic problem of calculating the complex conductivity of the diaphragm is solved. An equivalent circuit of the resonant diaphragm is proposed and the correspondence between the geometric dimensions of its aperture and the parameters of the circuit is determined. The synthesis results of an elliptic filter for a rectangular waveguide WR137 with passband of 7,5% and length of 34 mm are presented.