An Equivalent Circuit for the Design of E-Plane Metal-Insert Filters in Millimeter-Wave Applications

An equivalent circuit composed of a shunt inductance between two waveguide sections is proposed for the metal fins of an E-plane metal-insert filter. The parameters of the equivalent circuit have been computed by the mode-matching technique for a number of geometrical dimensions and frequencies. The resulting model allows a fast and accurate design of metal-insert filters, without resorting to time-consuming procedures of optimization based on field analysis.