Advanced analysis of propagation losses in rectangular waveguide structures using perturbation of boundary conditions

In this paper, propagation losses effects present in rectangular waveguide structures are rigorously considered. For this purpose, a new formulation based on the perturbation of the boundary conditions on the metallic walls of the waveguides combined with an Integral-Equation (IE) analysis technique is proposed. Following this advanced technique, the drawbacks of the classical power-loss method are overcome and a complex modal propagation constant is computed. To validate this theory, we have successfully compared our results with numerical data of lossy hollow waveguides. Next, a Computed-Aided-Design (CAD) software package based on such a novel modal analysis tool has been used to predict the propagation losses effects in a 2-pole symmetric bandpass filter.This work has been supported by Ministerio de Ciencia e Innovación, Spanish Government, under the Grant JC2009-0221 and the coordinated R&D project TEC2010-21520-C04, by University of Alicante under the project GRE10-22, as well as by the European COST Office under Action IC-0803 “RF/Microwave Communication Subsystems for Emerging Wireless Technologies (RFCSET)”