Full-wave analysis and applications of EBG waveguides periodically loaded with metal ridges

In this paper, a fast and accurate full-wave analysis tool of passive structures based on Electromagnetic-Bandgap (EBG) waveguides periodically loaded with metal ridges is proposed. For this purpose, a very efficient Integral Equation (IE) technique is followed to model the planar steps involving arbitrary waveguides. The well-known Boundary Integral - Resonant Mode Expansion (BI-RME) method is used to obtain the modal chart of the ridged waveguides. In order to show the advantages of this tool, a periodically loaded E-plane filter with improved stopband performance is analyzed and compared to standard implementation. Dispersion relations are also derived and used as guidelines for designing an EBG fifth-order low-pass filter

Multipactor effect analysis and design rules for wedge-shaped hollow waveguides

A numerical model for predicting the multipactor breakdown effect in wedge-shaped hollow waveguides is presented in this paper. The computation of electromagnetic fields is based on the boundary integral–resonant mode expansion method, which provides the modal chart of hollow waveguides with any arbitrary cross section. The advantage of using wedge-shaped waveguides with respect to conventional rectangular ones is the deviation of the resonant paths of the electrons toward regions with lower voltages, thus reducing the probability of multipactor threshold for certain input power. To validate this method, our results have been compared with simulations from previous theoretical studies. Once the simulation tool is validated, it is used to predict the multipactor threshold of wedge-shaped waveguides with different symmetric inclination angles of their horizontal plates. Finally, susceptibility curves as the ones already available for rectangular waveguides are presented. These charts are useful for designing innovative waveguide geometries with improved multipactor-free working power ranges.This work was supported by the Ministerio de Ciencia e Innovación, Spain, under Research Project TEC2007-67630-C03-01/TCM

Efficient coupling integrals computation of waveguide step discontinuities using BI-RME and Nyström methods

This paper describes a novel technique for the very efficient and accurate computation of the coupling integrals of waveguide step discontinuities between arbitrary cross section waveguides. This new technique relies on solving the Integral Equation (IE) that provides the well-known Boundary Integral - Resonant Mode Expansion (Bi-RME) method by the Nystrom approach, instead of using the traditional Galerkin version of the Method of Moments (MoM), thus providing large savings on computational costs. Comparative benchmarks between the results provided by the new technique and the original BI-RME method are successfully presented

Peak Power Handling Capability in Groove Gap Waveguide Filters Based on Horizontally Polarized Resonators and Enhancement Solutions

This letter studies the peak power handling capability (PPHC) in groove gap waveguide filters based on horizontally polarized resonators. Moreover, a modification of the resonant cavity is proposed, where the central pins of the original structure are replaced by a rounded metal block. As a result of this change, the TE₁₀₁-like mode can still be excited, but the maximum electric field strength is shifted to the center of the cavity, which leads to a higher PPHC. The main advantages of the original structure are maintained, and greater robustness in the manufacturing process is achieved. Next, some guidelines for the design of the coupling windows and the dimensions of the blocks are shown to minimize the electric field strength and, consequently, maximize the PPHC. Finally, two third-order bandpass filters (with pins and with blocks) centered at 16 GHz have been manufactured and tested in a measurement campaign, where a PPHC enhancement of 8.7 dB at high pressures is achieved for the novel solution presented in this work.This work was supported in part by the University of Alicante through the Fellowship Grant UAFPU2018-054 and in part by MCIN/AEI/10.13039/501100011033 through the Sub-Projects C41 and C43 of the Coordinated Project under Grant PID2019-103982RB

Caracterización modal eficiente de estructuras guiadas arbitrarias usando los métodos BI-RME y Nyström

This paper describes a novel technique for the very efficient and accurate full-wave modal analysis of cylindrical waveguides with arbitrary cross-sections. This new technique relies on solving the integral equations that provide the well-known Boundary Integral - Resonant Mode Expansion (BI-RME) method by the Nyström approach, instead of using the traditional Galerkin version of the Method of Moments (MoM), thus providing large savings on computational costs. Accuracy aspects of this simple and fast procedure, which are directly connected to the rigorous treatment of the singular behaviour of the integral equation kernels, are carefully considered for waveguides defined by straight, circular and/or elliptical arcs. Comparative benchmarks between the new technique and the original BI-RME method are successfully presented for singleand multi-ridged waveguides, elliptical waveguides and rectangular waveguides with rounded corners

Fast and accurate CAD tool of periodically loaded E-plane filters

In this paper, a fast and accurate Computer-Aided Design (CAD) tool of periodically loaded E-plane filters is proposed. The tool is based on a very efficient Integral Equation (IE) technique that provides a full-wave modal analysis of discontinuities between arbitrarily shaped waveguides, i.e. ridge waveguides, and rectangular ones. For solving the complete filter, the Boundary Integral - Resonant Mode Expansion (BI-RME) method is also employed. In order to show the advantages of this CAD tool, a periodically loaded E-plane filter with improved stop-band performance is analyzed and compared to standard solutions. For validation purposes, numerical and experimental results are successfully compared

Efficient CAD tool of complex passive devices composed of arbitrarily shaped waveguides using Nyström and BI-RME methods

This paper presents a novel CAD tool for the complete characterization of complex passive microwave devices in waveguide technology. The analysis is based on an Integral Equation (E)tec hnique that provides a very efficient characterization of discontinuities between waveguides with an arbitrary cross-section composed of linear, circular and elliptical am. The modal analysis of such waveguides is based on a modified version of the well-known Boundary Integral - Resonant Mode Expansion BI-RME) method using the Nystrom approach, instead of using the traditional Galerkin version of the Method of Moments (MOM), thus providing significant savings on computational costs. Previous results concerning this Nystrom BI-RME approach only compared the loss of accuracy in computing the modal spectrum of arbitrary waveguides. In this work, new comparative benchmarks between the results provided by the new technique and the original BI-RME method are successfully presented for real complex passive waveguide devices

Análisis eficiente de dispositivos complejos en microondas usando BI-RME y Nyström

This work presents the complete characterization of complex passive microwave devices in waveguide technology for linear, circular and elliptical geometries. The analysis is based on an Integral Equation (IE) technique that provides a very efficient characterization of discontinuities between waveguides with an arbitrary cross-section. The modal analysis of such waveguides is based on a modified version of the well-known Boundary Integral - Resonant Mode Expansion (BI-RME) method using the Nyström approach, instead of using the traditional Galerkin version of the Method of Moments (MoM), thus providing significant savings on computational costs. Previous results concerning this Nyström BI-RME approach only compared the loss of accuracy in computing the modal spectrum. In this work, new comparative benchmarks between the results provided by the new technique and the original BI-RME approach are successfully presented for a selected choice of real complex passive microwave devices

CAD of complex passive devices composed of arbitrarily shaped waveguides using Nyström and BI-RME methods

In this paper, a novel computer-aided design (CAD) tool of complex passive microwave devices in waveguide technology is proposed. Such a tool is based on a very efficient integral-equation analysis technique that provides a full-wave characterization of discontinuities between arbitrarily shaped waveguides defined by linear, circular, and/or elliptical arcs. For solving the modal analysis of such arbitrary waveguides, a modified version of the well-known boundary integral-resonant-mode expansion (BI-RME) method using the Nyström approach, instead of the traditional Galerkin version of the method of moments, is proposed, thus providing significant savings on computational costs and implementation complexity. The novel theoretical aspects of this Nyström approach, as well as their impact on the original BI-RME formulation, are fully described. Comparative benchmarks between this new technique and the classical BI-RME formulation using Galerkin are successfully presented for the full-wave analysis of frequently used irises (i.e., rectangular cross-shaped and circular multiridged) and for the CAD of complex waveguide components (such as rectangular waveguide filters considering mechanization effects and dual-mode circular waveguide filters with elliptical irises).This work was supported by the Ministerio de Ciencia y Tecnología, Spanish Government, under the Special Action of Space National Plan ESP2001-4547-PE

Efficient full wave modal analysis of arbitrarily shaped waveguides using BI-RME and Nyström methods

This paper describes a novel technique for the very efficient and accurate full-wave modal analysis of cylindrical waveguides with arbitrary cross-section. This new technique relies on solving the integral equations that provide the well-known Boundary Integral - Resonant Mode Expansion (BI-RME) method by the Nyström approach, instead of using the traditional Galerkin version of the Method of Moments (MoM), thus providing large savings on computational costs. Accuracy aspects of this simple and fast procedure, which are directly connected to the rigorous treatment of the singular behaviour of the integral equation kernels, are carefully considered for waveguides defined by straight, circular and/or elliptical arcs. Comparative benchmarks between the new technique and the original BI-RME method are successfully presented for single- and multi-ridged waveguides, elliptical waveguides and rectangular waveguides with rounded corners