Caracterización modal de guías arbitrarias y aplicación a dispositivos de microondas

En esta tesis se desarrollan una serie de técnicas de análisis y diseño de dispositivos de microondas que harán hincapié en la necesidad de precisión y eficiencia en los mencionados procesos tanto para analizar como para diseñar dispositivos de microondas que se describirán de manera exhaustiva en la tesis. A su vez, se desarrollan técnicas de aceleración de algoritmos de análisis que reducen en gran medida el tiempo de caracterización de estructuras que componen los dispositivos. Debido a la complejidad de los dispositivos actuales, un incremento en la velocidad de análisis mejora a su vez los tiempos requeridos para el diseño y desarrollo de estos complejos dispositivos. Esto es debido a que las técnicas CAD requieren algoritmos de optimización que invocan a los módulos de análisis repetidas veces. Este objetivo de aumento de velocidad y precisión en el análisis y diseño ha requerido una cuidadosa elección de técnicas así como una profunda mejora de las mismas.Cogollos Borras, S. (2002). Caracterización modal de guías arbitrarias y aplicación a dispositivos de microondas [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/5081Palanci

Analysis and design of re-configurable combline filters using dielectric tuners

[EN] This article describes different tunable structures for typical waveguide combline filters. In this context, several configurations using dielectric tuners have been studied for resonators, inter-resonator couplings, and input/output couplings. All configurations are analyzed in a wide frequency range showing advantages and drawbacks. Using the best structures in terms of performance, a fully re-configurable filter has been designed. The filter provides a wide tuning range in terms of center frequency while maintaining a high Q factor, and a constant bandwidth and return losses. A first filter prototype has been designed at L-band. The structure demonstrates a tunability in terms of frequency range of about 400 %, thereby clearly demonstrating that the approach we propose is indeed a very promising candidate for implementing tunable combline filters based on dielectric tuners.Sharma, A.; Cogollos, S.; Boria Esbert, VE.; Guglielmi, M. (2022). Analysis and design of re-configurable combline filters using dielectric tuners. IEEE. 122-125. https://doi.org/10.23919/EuMC50147.2022.978434512212

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

A New Family of Multiband Waveguide Filters Based on a Folded Topology

[EN] In this article, we describe a new family of multiband waveguide filters based on a folded topology. The folded topology allows to use the filters of different orders and the introduction of transmission zeros. The design of the multiband filter is based on the aggressive space mapping (ASM) technique and is able to take into account manufacturing details, such as round corners and tuning elements. The filter structure is validated by designing, manufacturing, and measuring a triband filter. The agreement between simulations and measurements is shown to be excellent, thereby fully validating both the filter topology and the design process.This work was supported in part by the La Caixa Foundation under Grant B004442 and in part by the Agencia Estatal de Investigacion (AEI) and Union Europea through the Fondo Europeo de Desarrollo Regional (FEDER) "Una manera de hacer Europa" (AEI/FEDER, UE) under Research Project TEC2016-75934-C4-1-R.Melgarejo, JC.; Cogollos, S.; Guglielmi, M.; Boria Esbert, VE. (2020). A New Family of Multiband Waveguide Filters Based on a Folded Topology. IEEE Transactions on Microwave Theory and Techniques. 68(7):2590-2600. https://doi.org/10.1109/TMTT.2020.2989111S2590260068

Compact Wideband Hybrid Filters in Rectangular Waveguide With Enhanced Out-of-Band Response

[EN] This paper describes the design procedure of a compact wideband waveguide filter, based on stepped impedance resonators (SIR) and a combined usage of capacitive and inductive coupling irises, that provides a significant improvement in the out-of-band response of the filter with respect to the state-ofthe- art. In addition to theory, several filter prototypes have been designed and manufactured. A detailed sensitivity analysis has been also carried out. Finally, simulations and measurements are compared, showing very good agreement, thereby fully validating the new filter topology.This work was supported in part by the Ministerio de Economia y Empresa (MINECO) (Spanish Government) through the R&D Project under Grant TEC2016-75934-C4-1-R and in part by Generalitat Valenciana through Santiago Grisolia under Grant GRISOLIA/2017/073.Valencia-Sullca, JF.; Boria Esbert, VE.; Guglielmi, M.; Cogollos, S. (2020). Compact Wideband Hybrid Filters in Rectangular Waveguide With Enhanced Out-of-Band Response. IEEE Transactions on Microwave Theory and Techniques. 68(1):87-101. https://doi.org/10.1109/TMTT.2019.2947911S8710168

Hybrid Wideband Staircase Filters in Rectangular Waveguide With Enhanced Out-of-Band Response

[EN] The objective of this article is to describe the design of a new family of wideband filters in a rectangular waveguide based on hybrid couplings and a staircase configuration. The use of E-plane T-junctions and E-plane folded structures is also discussed, in order to enhance the out-of-band response and the selectivity of the filter with respect to the current state of the art. The design of several hybrid filter prototypes is discussed in detail, including manufacturing sensitivity and high-power analysis. Finally, simulations and measurements for an eight-pole filter prototype are also compared, showing very good agreement, thereby fully validating both the design procedure and the new filter topology that we propose.This work was supported in part by the Ministerio de Ciencia e Innovacion (Spanish Government) through the R&D Project under Grant PID2019-103982RB-C41 and in part by Generalitat Valenciana under Santiago Grisolia Grant GRISOLIA/2017/073.Valencia-Sullca, JF.; Guglielmi, M.; Cogollos, S.; Boria Esbert, VE. (2021). Hybrid Wideband Staircase Filters in Rectangular Waveguide With Enhanced Out-of-Band Response. IEEE Transactions on Microwave Theory and Techniques. 69(8):3783-3796. https://doi.org/10.1109/TMTT.2021.30760613783379669

Compact Dual-Band and Wideband Filters With Resonant Apertures in Rectangular Waveguide

[EN] The objective of this article is to describe a new family of microwave bandpass filters in the rectangular waveguide based on resonant apertures, which can be used to implement both single- and dual-band transfer functions. The use of capacitive stubs and a staircase configuration is also discussed in order to enhance the out-of-band response and the selectivity of the filter with respect to the state of the art. Finally, simulations are compared with measured results, showing very good agreement, thereby fully validating both the new filter topologies and the design procedure.This work was supported in part by the Ministerio de Ciencia e Innovacion, Spanish Government, through the Research and Development Project PID2019-103982RB, under Grant MCIN/AEI/10.13039/501100011033; and in part by the Generalitat Valenciana under Santiago Grisolia Grant GRISOLIA/2017/073. This article is an expanded version from the IEEE MTT-S International Microwave Symposium (IMS 2021), Atlanta, GA, USA, June 20-25, 2021 [DOI: 10.1109/IMS19712.2021.9574801].Valencia Sullca, JF.; Cogollos, S.; Boria Esbert, VE.; Guglielmi, M. (2022). Compact Dual-Band and Wideband Filters With Resonant Apertures in Rectangular Waveguide. IEEE Transactions on Microwave Theory and Techniques. 70(6):3125-3140. https://doi.org/10.1109/TMTT.2022.31623073125314070

A New Family of Reconfigurable Waveguide Filters and Diplexers for High-Power Applications

In this paper, we discuss how the use of the recently developed modified tuning pin (MTP) can be extended to the design of filters and diplexers implemented in rectangular waveguide, that can be reconfigured in a number of discrete states, and that can be used in high-power payloads. As an application example, the design of two reconfigurable filters and a reconfigurable diplexer is fully described. The highpower behavior of these components (in particular, with respect to corona and multipaction effects) is also studied in detail, in order to demonstrate that the structures that we discuss can operate correctly under highpower conditions. Furthermore, comparisons between simulations and measurements of several prototypes are also included, showing an excellent agreement between simulated and experimental data, thereby fully validating both the design approach and the filter reconfiguration strateg

Inductive Cascaded Quadruplet With Diagonal Cross-Coupling in Rectangular Waveguide

[EN] The objective of this paper is to show how inductive quadruplets with diagonal cross-couplings can be used as building blocks for filters in rectangular waveguide. Starting with the coupling matrix synthesis, we show how very general transfer functions can be easily implemented with a very simple step-by-step procedure. In addition to coupling matrix theory, we also describe distributed networks that can be effectively used to carry out the transition from coupling matrix descriptions to actual waveguide structures. Several filter design examples are also described in detail. Finally, measured results are also discussed showing excellent agreement with simulations, thereby fully validating both the new family of filter structures and the related design procedures.This work was supported by the Ministerio de Ciencia e Innovacion (MICIN) (MICIN/AEI/10.13039/501100011033), Spanish Government, through the Research and Development Project under Grant PID2019-103982RB-C41.Cogollos, S.; Cameron, RJ.; Guglielmi, M.; Melgarejo, JC.; Boria Esbert, VE. (2022). Inductive Cascaded Quadruplet With Diagonal Cross-Coupling in Rectangular Waveguide. IEEE Access. 10:45241-45255. https://doi.org/10.1109/ACCESS.2022.316977445241452551

Novel Planar and Waveguide Implementations of Impedance Matching Networks Based on Tapered Lines Using Generalized Superellipses

(c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this[EN] For the practical implementation of RF and microwave impedance matching networks, a widely employed solution¿alternative to the use of classical impedance transformers¿is based on tapered lines. This paper shows a simple method to design smooth tapers that take into account the dispersion of the line and the required design bandwidth simultaneously. A planar taper has been designed in microstrip technology with the same length of classical ones but improving their performances. A waveguide prototype has also been designed with similar performance to a commercial one but with one third of its length. Both tapered structures have been obtained through the optimization of very few parameters using the same design strategy. As a result, the reflection coefficient of the tapers can be optimally adapted to a given specific mask using the prescribed value of physical length. Experimental results for both tapers are included for the validation of the proposed topologies and the related design method.This work was supported by MINECO (Spanish Government) through R&D under Project TEC2016-75934-C4-1-R.Cogollos, S.; Vague Cardona, JJ.; Boria Esbert, VE.; Martínez Pérez, JD. (2018). Novel Planar and Waveguide Implementations of Impedance Matching Networks Based on Tapered Lines Using Generalized Superellipses. IEEE Transactions on Microwave Theory and Techniques. 66(4):1874-1884. https://doi.org/10.1109/TMTT.2018.2791952S1874188466