Rigorous evaluation of propagation losses in arbitrarily shaped waveguide structures using boundary integral resonant mode expansion and perturbation of boundary conditions

This paper is a preprint of a paper submitted to IET Microwaves Antennas and Propagation and is subject to Institution of Engineering and Technology Copyright. If accepted, the copy of record will be available at IET Digital Library The accurate consideration of propagation losses in arbitrarily shaped waveguide-based structures is studied in this paper. For such a purpose, a software tool based on the perturbation of the boundary conditions on the waveguide metallic walls and on the boundary integral resonant mode expansion method has been developed. To show the advantages of the proposed technique with respect to the classic power-loss method, the complex propagation wavenumbers of a double ridge and an elliptical waveguide have been first computed and compared with results of a commercial software based on the finite element technique. Next a circular, a sectorial shaped and a triangular shaped waveguide have been considered. Then, a computer-aided design software package based on this modal analysis tool has been applied to predict the propagation loss effects in complex waveguide structures, such as an evanescent mode ridge waveguide filter, a traditional dual mode filter with circular cavities and a twist component for K-band applications. This work has been supported by the Ministerio de Economia y Competitividad (MINECO), Spanish Government, by the coordinated R&D project TEC 2010-21520-C04 and the Grant JC 2009-0221, and by University of Alicante under the project GRE 10-22. Marini, S.; Soto Pacheco, P.; Mattes, M.; Gimeno Martinez, B.; Bleda Pérez, S.; Vidal Pantaleoni, A.; Boria Esbert, VE. (2014). Rigorous evaluation of propagation losses in arbitrarily shaped waveguide structures using boundary integral resonant mode expansion and perturbation of boundary conditions. IET Microwaves Antennas and Propagation. 8(12):980-989. https://doi.org/10.1049/iet-map.2013.0414