Filters based on thin inductive irises in a circular waveguide

Abstract

Bandpass filters (BPF) based on planar-transverse inhomogeneities in a circular waveguide with an azimuthally inhomogeneous wave mode H₁₁ find application in radioengineering systems which operate on two mutually orthogonal polarizations. Below we present the results of a theoretical and experimental investigation of BPF based on thin inductive irises in a circular waveguide. A filter having a Chebyshev or maximally flat frequency response of the inserted attenuation is calculated (see [1]) in the one-wave approximation without allowance for the mutual effect of the irises with respect to waves of the higher modes or for losses in the resonators. The synthesis of the filter (see [1]) is based on iterative calculation of the coefficients of reflection from the irises from the parameters of the impedance inverters, which are determined from the initial stipulation governing the amplitude-frequency response (AFR).