Electrodynamic Analysis and Synthesis of an Elliptic Filter Based on Complex Resonant Irises in a Rectangular Waveguide

Abstract

We have synthesized elliptic bandpass waveguide filters. The resonators of the filter are thin plane-transverse resonant irises with an aperture in the form of a rectangular window with two metal L-shaped ridges. The electrodynamic problem of calculating the complex conductance of the iris is solved. An equivalent circuit of the resonant iris is proposed, and the correspondence of the geometric size of its aperture to the parameters of the circuit is established. The results of synthesis of an elliptic filter for the WR137 rectangular waveguide with a passband of 6.35–6.83 GHz at a level of −3 dB are presented. The longitudinal size of the filter is 34 mm, which ensures the small size of the developed device.