ANÁLISIS Y DISEÑO OPTIMIZADO DE DISPOSITIVOS PASIVOS DE MICROONDAS DE BANDA AMPLIA CON GUÍAS DE SECCIÓN TRANSVERSAL ARBITRARIA

La evolución actual de los sistemas de telecomunicación se caracteriza por la optimización constante en el uso y en el manejo del ancho de banda, para poder ofertar así el mayor rango posible de servicios a los usuarios y al menor coste posible. El área de los dispositivos pasivos de microondas, tanto en lo que respecta a enlaces terrestres como a las comunicaciones espaciales, no ha sido ajeno a esta evolución. De hecho, este campo ha experimentado grandes avances en los últimos años para poder cumplir con unos requisitos cada vez más exigentes, lo que ha fomentado la aparición de nuevos dispositivos e importantes mejoras en los ya existentes. El trabajo desarrollado en esta tesis se enmarca dentro de este contexto, y pretende contribuir a la mejora de los procedimientos de análisis y diseño de aquellos dispositivos pasivos de microondas que deben satisfacer unas especificaciones que abarquen un amplio ancho de banda. Es importane destacar que, conforme avanza la tecnología, la influencia de estos dispositivos en las prestaciones finales de los sistemas de telecomunicación es cada vez más importante. Esta tesis se centra en las tres familias de filtros de microondas en tecnología de guía onda probablemente más habituales en la práctica: los filtros inductivos, los filtros de modo evanescente y los filtros corrugados. No obstante, muchos de los procedimientos aquí desarrollados y los resultados obtenidos se podrían también extender a otros dispositivos pasivos con un gran ancho de banda de operación. En primer lugar se han implementado una serie de herramientas basadas en técnicas modales, las cuales permiten realizar el análisis de estos componenetes de una forma extremadamente precisa y eficiente. Para poder ampliar el rango de aplicación de las técnicas modales a dispositivos con guías no canónicas, se ha desarrollado a su vez un nuevo procedimiento para obtener con gran rapidez y rigurosidad el espectro modal de guías con una sección transversal prácticamente arbitraria.Soto Pacheco, P. (2012). ANÁLISIS Y DISEÑO OPTIMIZADO DE DISPOSITIVOS PASIVOS DE MICROONDAS DE BANDA AMPLIA CON GUÍAS DE SECCIÓN TRANSVERSAL ARBITRARIA [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/15865Palanci

Distributed Models for Filter Synthesis

The limitations of filter synthesis methods based on classic equivalent circuits with the enhanced distributed models and synthesis procedures able to overcome such limitations are presented. A modified procedure that corrects the waveguide lengths has been proposed. The input and output reflection coefficients of the ideal prototype steps are real. The shunt capacitive effect introduces a phase shift in the reflection coefficients of each waveguide step. The representation of the filter structure can be improved if the waveguide steps are analyzed with a full-wave electromagnetic (EM) simulator, and their responses are stored in the form of ABCD matrices. The desired filter passband cutoff frequency was 11 GHz, with a specified return loss of 25 dB, and a gap height greater than 4.25 mm. High-power applications with wide stopbands often require impractical waveguide sections. The accurate EM simulators are used to find an almost exact equivalence between the prototype and the filter parts.Boria Esbert, VE.; Soto Pacheco, P.; Cogollos Borras, S. (2011). Distributed Models for Filter Synthesis. IEEE Microwave Magazine. 12(6):87-100. doi:10.1109/MMM.2011.942010S8710012

Capacitive Obstacle Realizing Multiple Transmission Zeros for In-Line Rectangular Waveguide Filters

(c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other worksThis paper presents a capacitive obstacle for rectangular waveguide filters capable of realizing multiple transmission zeros (TZs). By combining a capacitive window with multiple thin stubs, a filter designer has the ability to control the total coupling implemented by the obstacle, and the frequency location of the TZs generated. The resulting structure is compact, and can be employed at the input/output and intermediate stages of direct-coupled-resonator filters. This letter includes a parametric analysis of the obstacle and practical design guidelines. To validate its practical application, an in-line five-pole filter realizing three TZs has been successfully realized.This work was supported by the Spanish Ministerio de Economia y Competitividad under R&D project TEC2013-47037-C5-1-R.Carceller Candau, C.; Soto Pacheco, P.; Boria Esbert, VE.; Guglielmi, M. (2016). Capacitive Obstacle Realizing Multiple Transmission Zeros for In-Line Rectangular Waveguide Filters. IEEE Microwave and Wireless Components Letters. 26(10):795-797. https://doi.org/10.1109/LMWC.2016.2605462S795797261

A New Model to Determine Passive Intermodulation Terms When Non-Contributing Carriers are Added to Classical Scenarios

[EN] This paper provides a new theoretical model for the characterization of passive intermodulation behaviour when non-contributing carriers (i.e., carriers which do not directly affect the particular non-linear contribution under analysis) are added to classical two or three carriers scenarios. According to traditional models, the power of a particular passive intermodulation frequency term is only related to the contributing carriers which combines in non-linear way to generate this term, thus the presence of additional (i.e., non-contributing) carriers should not affect to the predicted power of such an intermodulation product. However, recent laboratory tests reveal that non-contributing carriers do reduce the power of unrelated passive intermodulation terms. A heuristic model is proposed in this work to explain this effect, which shows a good matching with measured results already published in the technical literature. The study is focused in third order non-linear contributions, as being the most critical in practical applications.This work was supported in part by the Ministerio de Ciencia e Innovacion (Spanish Government) under Research and Development Project PID2019-103982RB-C41, and in part by the European Regional Development Fund.Smacchia, D.; Soto Pacheco, P.; Boria Esbert, VE.; Raboso García-Baquero, D. (2021). A New Model to Determine Passive Intermodulation Terms When Non-Contributing Carriers are Added to Classical Scenarios. IEEE Access. 9:152070-152074. https://doi.org/10.1109/ACCESS.2021.3126903S152070152074

A Wideband Diplexer for Ka-Band Passive Intermodulation Measurement

In this paper we propose a novel Ka-band waveguide diplexer for passive intermodulation (PIM) measurements. Due to the higher operating frequency, this type of measurement setup usually requires wideband filters. In addition, due to the very large separation between satellite uplink and downlink bands, the PIM measurement diplexer unit must operate over a very wide frequency band. To satisfy such wide bandwidth requirements, the proposed topology is based on a band-reject filter for the downlink frequency band which is designed to provide, at the same time, the optimal passband performance for the downlink, and the optimal equiripple rejection over the PIM band. For the PIM channel, a band-pass filter combined with a high-pass section has been used. To validate the design, a prototype has been designed and manufactured. Very good agreement is shown between simulations and measurements, thereby fully validating the proposed solution.Smacchia, D.; Carceller, C.; Guglielmi, M.; Soto Pacheco, P.; Boria Esbert, VE.; Ruiz, J.; González-Santatecla, P. (2018). A Wideband Diplexer for Ka-Band Passive Intermodulation Measurement. IEEE. 1106-1109. https://doi.org/10.1109/MWSYM.2018.84391911106110

A 3D Smith Chart based on the Riemann Sphere for Active and Passive Microwave Circuits

“© © 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.”This letter proposes a spherical 3-D Smith Chart suitable for representing both active and passive microwave circuits. Using the mathematical concept of the Riemann sphere, the extended reflection coefficient plane is transformed into the surface of the unit sphere. Since the proposed Smith Chart compiles the whole complex plane, all possible loads are included. A simple graphic tool is thus obtained that successfully unifies active and passive circuits. In addition, lossy lines with complex characteristic impedances can also be represented. The letter presents the 3-D Smith Chart, provides its main governing equations, and also enumerates its more important properties. © 2011 IEEE.This work was supported in part by the POSDRU ID 7713 European Project and by the Ministerio de Ciencia e Innovacion, Spanish Government under Research Project TEC2010-21520-C04-01.Muller, AA.; Soto Pacheco, P.; Dascalu, D.; Neculoiu, D.; Boria Esbert, VE. (2011). A 3D Smith Chart based on the Riemann Sphere for Active and Passive Microwave Circuits. IEEE Microwave and Wireless Components Letters. 21(6):286-288. https://doi.org/10.1109/LMWC.2011.2132697S28628821

Practical Design of Filters Using EBG Waveguides Periodically Loaded with Metal Ridges

[EN] The dispersion diagram of infinite periodic structures is useful for the practical design of waveguide filters. Starting from the dispersion diagram of a unit cell, it is possible to generate a finite structure with very similar pass- and stop-bands (gaps). However, truncation of the infinite periodic structure degrades the pass-band performance. In this paper, these impairments are overcome by means of suitable waveguide tapers matching the impedance of the periodic structure to the access ports. As a result, the design of practical low-pass filters, derived from passive structures based on Electromagnetic Band-Gap (EBG) waveguides periodically loaded with metal ridges, is successfully addressed. According to this procedure, a five-order and an eight-order EBG low-pass filters are obtained after an optimization step. Measurements of a manufactured prototype fully validate the proposed approach.This work was supported by the Ministerio de Economía y Competitividad (MINECO), Spanish Government, under the R&D projects TEC2013-47037-C5-1-R and TEC2013-47037-C5-4-R. The authors would like to thank ITACA (Instituto de Aplicaciones de las Tecnologías y de las Comunicaciones Avanzadas), from Technical University of Valencia (Valencia, Spain), for their support in the accurate manufacturing of the low-pass filter prototypeMarini, S.; Soto Pacheco, P.; Coves, A.; Gimeno Martinez, B.; Boria Esbert, VE. (2016). Practical Design of Filters Using EBG Waveguides Periodically Loaded with Metal Ridges. Progress in ElectromagneticsResearch C. Pier C. 63:13-21. https://doi.org/10.2528/PIERC15111603S13216

Design of Compact Wideband Manifold-Coupled Multiplexers

The design of manifold-coupled multiplexers for wideband applications is considered in this paper. A systematic procedure, based on the sequential connection of filters to the manifold and subsequent adjustment of the interconnection elements, is presented. The filters are attached to the manifold without using stubs in order to minimize the effect of spurious resonances. The interconnection elements, the manifold, and the remaining filters are considered as the first inverter of each new filter that is attached. This technique has been applied to several practical examples. The obtained results validate the proposed design methodology.This work was supported by the Spanish Ministerio de Economi-a y Competitividad under Research and Development Project TEC2013-47037-C5-1-R.Carceller Candau, C.; Soto Pacheco, P.; Boria Esbert, VE.; Guglielmi, M.; Gil Raga, J. (2015). Design of Compact Wideband Manifold-Coupled Multiplexers. IEEE Transactions on Microwave Theory and Techniques. 63(10):3398-3407. https://doi.org/10.1109/TMTT.2015.2460738S33983407631

On Multimode Equivalent Network Representation of Finite Arrays of Open-Ended Waveguides

[EN] This communication describes a multimode equivalent network (MEN) representation of a finite array of open-ended lossless waveguides on an infinite ground plane. The derivation is based on an integral equation formulated at the interface between the waveguides and the free-space region. The MEN is formulated using the concept of accessible and localized modes, and includes ports for the free-space plane waves. The MEN derived can be easily combined with the MENs of other microwave components, thus allowing for the accurate analysis and design of more complex systems composed of waveguide elements and radiating apertures. Both simulated and experimental results are presented showing a very good agreement, thereby fully validating the proposed equivalent network representation.This work was supported in part by the Spanish Ministry of Economics and Competitiveness under Project TEC2013-47360-C3-3-P, Project TEC2016-79700-C2-1-R, Project TEC2016-78028-C3-3-P, Project TEC2013-47037-C5-1-R, and Project TEC2016-75934-C4-1-R and in part by the Generalitat Valenciana under Project GV/2015/065.Sánchez-Escuderos, D.; Baquero Escudero, M.; Soto Pacheco, P.; Boria Esbert, VE.; Guglielmi, M. (2017). On Multimode Equivalent Network Representation of Finite Arrays of Open-Ended Waveguides. IEEE Transactions on Antennas and Propagation. 65(8):4334-4339. https://doi.org/10.1109/TAP.2017.2710267S4334433965

Efficient full-wave modal analysis of waveguides with arbitrary geometry defined by straight, circular and elliptical segments

Many modern waveguide devices, such as dual-mode filters and diplexers, can be modelled considering the whole circuit as a cascade of waveguide step discontinuities. Most of such discontinuities usually involve waveguides with arbitrary cross-section defined by linear, circular and/or elliptical segments. A fast and accurate procedure for the full-wave modal characterization of such arbitrarily shaped waveguides is based on the Boundary Integral— Resonant Mode Expansion (BI-RME) technique well described in [1]. In this paper, we present a very efficient implementation of a full-wave modal analysis tool for arbitrarily shaped waveguides based on the BI-RME theory.This work was supported by the European Commission under the Research and Training Networks Programme, Contract No. HPRN-CT-2000-00043