Efficient boundary integral-resonant mode expansion method implementation for full-wave analysis of passive devices based on circular waveguides with arbitrary perturbations

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 LibraryIn this study, the efficient full-wave analysis of passive devices composed of circular and arbitrarily-shaped waveguides is considered. For this purpose, the well-known boundary integral-resonant mode expansion (BI RME) method has been properly extended. Circular waveguides are used for resonant mode expansion, whereas the arbitrary contour is defined by any combination of straight, circular and elliptical segments, thus allowing the exact representation of the most widely used geometries. The proposed algorithm extends previous implementations of the BI RME method based on circular waveguides by considering circular and elliptical arcs for defining arbitrary geometries. Similarly, it allows the efficient analysis of passive devices based on circular waveguides with arbitrary perturbations, thus providing more accurate results with less computational efforts than a rectangular waveguide-based BI RME approach. The extended method has been successfully tested with several practical application examples, having compared its performance with the BI RME method based on rectangular waveguides.This work was supported by Ministerio de Ciencia e Innovacion, Spanish Government, under Research Project TEC2010-21520-C04-01.Carceller Candau, C.; Cogollos Borras, S.; Soto Pacheco, P.; Gil Raga, J.; Boria Esbert, VE.; Vicente Quiles, CP.; Gimeno Martinez, B. (2013). Efficient boundary integral-resonant mode expansion method implementation for full-wave analysis of passive devices based on circular waveguides with arbitrary perturbations. IET Microwaves Antennas and Propagation. 7(1):44-53. https://doi.org/10.1049/iet-map.2012.0603S44537

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 LibraryThe 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.2013.0414S98098981

A New Method for the Measurement of the Cutoff-Frequency of Varactor Diodes

(Adopted as a standard by the IEC

Meaning of the negative impedance

It is shown that the negative real part of an input impedance does not mean instability of the related circuit. A negative real part of the input impedance means only that the concerned circuit is active