Use of 3D field simulators in the synthesis of waveguide capacitive iris coupled lowpass filters

This paper presents the generalized lowpass filter design method of Levy ba sed on three-dimensional electromagnetic analysis and discontinuity modelin g using commercially available full-wave electromagnetic simulators, It sho ws how to use Levy's method for very accurate theoretical design of a waveg uide capacitive iris lowpass filter, using modern 3D EM field-solvers based on the finite element method (FEM), the mode matching method (MM), and the transmission line matrix (TLM) analysis method, This is the first time tha t design curves and equations, based on full electromagnetic modeling, have been presented for constant thickness capacitive iris filters, We will dem onstrate our approach by designing a number of waveguide capacitive iris fi lters. This paper also demonstrates the generality of the method. This meth od can be applied to many other types of waveguide lowpass and bandpass fil ters. (C) 2000 John Wiley & Sons, Inc.