Open Access
Multipactor breakdown analysis of Ku-band meandered low-pass filter
(2022) Sami, Abdul; Teberio Berdún, Fernando; Arnedo Gil, Israel; Martín Iglesias, Petronilo; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Arregui Padilla, Iván; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In this work, a very compact rectangular waveguide low-pass filter with meandered topology based on commensurate lines for Ku-band satellite applications is analysed for high-power handling capabilities. The device consists of rectangular waveguide sections properly cascaded to form a meandered topology to obtain the desired value of the local reflection coefficients. which are essential to achieve the target frequency response and also to keep large mechanical gaps. Hence, this technique allows us not only to design a filter with compact size but a filter geometry which is suitable for high power applications. In the paper, the low-pass filter based on commensurate lines is first designed by cascading E-plane mitered bends (±90° EMBs) in CST Microwave Studio (MWS) and then the values of the electromagnetic fields at the passband frequencies are exported to Spark3D to perform a multipactor analysis. The critical areas inside the device where the multipactor discharge occurs will also be identified in the high-power analysis. https://doi.org/10.5281/zenodo.7343236
Open Access
Sistema de medición de condiciones atmosféricas basado en el estudio del flujo de muones
(Universidad de Castilla La Mancha, 2024) Armendáriz Armenteros, Miguel Ángel; Vertiz Conde, Amaia; Martín Iglesias, Petronilo; Gómez Laso, Miguel Ángel; Muro Pérez, Aitor; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
To date, there is no straightforward method for monitoring meteorological conditions in real-time through experimental measurements. Consequently, all weather predictions rely on forecasting models, which are unable to adapt to actual weather changes, thereby compromising their accuracy. The project described in this paper seeks to establish a weather measurement system that leverages the relationship between climatic conditions and the phenomena of cosmic ray degradation and muon generation. If this relationship is accurately defined, it could lead to the development of a model that predicts atmospheric conditions based on the flux of muons and cosmic rays and the occurrence of the aforementioned phenomena. This paper provides a theoretical foundation to support the viability of the project, outlines the proposed configuration of the system, and discusses the implementation of its most crucial components. This project was undertaken by students from the Degree in Engineering in Telecommunication Technologies at the Public University of Navarre (UPNA), within the course Projects in Telecommunication Systems
Embargo
Additive manufacturing-oriented designs for space RF/microwave applications and high-power considerations
(2025) Martín Iglesias, Petronilo; Gómez Laso, Miguel Ángel; Boria Esbert, Vicente; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektriko eta Elektronikoaren eta Komunikazio Ingeniaritzaren
This thesis delves into the intricate relationship between additive manufacturing and high-power operation within the field of RF/microwave components. Two fundamental themes guide this research: advancements in materials and a deep understanding of material characterization, particularly focusing on the impact of properties like surface roughness on Secondary Electron Emission (SEE) and high-frequency performance. These themes are deeply intertwined, with a comprehensive grasp of one significantly influencing the others. For instance, a thorough understanding of a specific additive manufacturing process and its inherent characteristics is crucial for optimizing the design of components that fully exploit the process’s unique capabilities, streamlining the design and analysis phases, and ultimately pushing the boundaries of RF performance by increasing power handling or miniaturizing components. This understanding serves as the foundation for selecting the most suitable additive manufacturing process for a given application. Chapters 2, 3, and 4 provide concrete examples of this interplay, demonstrating how surface roughness can be strategically manipulated to minimize multipactor risk and enhance peak power handling, intentionally increased to create effective metal loads with good impedance matching, or carefully reduced to optimize performance at high power levels. Furthermore, this thesis introduces a novel material with exceptional thermal stability, promising significant advancements in high-power device performance by offering a compelling pathway towards improved thermal conductivity and enhanced operational stability.
Open Access
Integrating multiple stubs in stepped-impedance filter aiming for high selectivity
(IET, 2022) Sami, Abdul; Gómez Laso, Miguel Ángel; Lopetegui Beregaña, José María; Arnedo Gil, Israel; Calero Fernández, Ibai; Teberio Berdún, Fernando; Martín Iglesias, Petronilo; Benito Pertusa, David; Arregui Padilla, Iván; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
A design technique to include multiple and fully-controlled transmission zeros (TZs) in the frequency response of rectangular waveguide commensurate-line stepped-impedance filters is presented in this letter. These bandpass filters (BPFs) are known for having reduced sensitivities against manufacturing inaccuracies and are composed of multiple waveguide sections. In order to improve their selectivity, 3λg/4 and λg/4-stubs are included to create multiple TZs around the passband. The proposed technique allows us to add multiple stubs in a single section and, therefore, only minor adjustments in the affected part of the filter are required, which simplifies the overall design process. The technique has been verified with a design example with four TZs (two on each side) near the passband.
Open Access
Diseño de filtros en tecnología de línea coaxial sin dieléctricos mediante impresión 3D
(Universidad de Castilla La Mancha, 2024) Pons Abenza, Alejandro; Arregui Padilla, Iván; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Álvarez Botero, Germán Andrés; Martín Iglesias, Petronilo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
This article presents the design and manufacturing of a fully metallic X-band bandpass filter in coaxial-line technology. The device is 3D-printed as a self-supported structure without any dielectric inside. A short-circuit λ/4 parallel stub bandpass filter provides the required mechanical support for the self-supported 3D-printing process. To enhance filter out-of-band performance, a second stage consisting of a stepped-impedance low-pass filter is integrated, also using coaxial-line technology. Both filters are designed separately and then combined to achieve desired frequency specifications. A prototype with a passband at X-band (between 8 and 12 GHz) is manufactured using Selective Laser Melting, showing excellent agreement between simulations and measurements. This approach promises highly integrated, multifunctional monoblock coaxial filters with additional benefits such as increased RF shielding and protection against electrostatic discharge.
Open Access
Integración de múltiples stubs en filtros de saltos de impedancias de alta selectividad
(URSI, 2023) Gómez Laso, Miguel Ángel; Sami, Abdul; Lopetegui Beregaña, José María; Martín Iglesias, Petronilo; Álvarez Botero, Germán Andrés; Pons Abenza, Alejandro; Arregui Padilla, Iván; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
Rectangular waveguide commensurate-line stepped-impedance bandpass filters have been shown to have an increased fabrication robustness using conventional CNC milling. In this paper, their frequency response is improved by adding multiple transmission zeros at fully-controlled positions around the passband. The technique starts with the design of the filter without transmission zeros and only requires that one of the filter sections is slightly redesigned, while the rest keep unaltered, when lambda_g/¿¿ and 3*lambda_g/¿¿ stubs are included in the section to increase the overall filter selectivity around the passband. The design example is a 7th-order Chebyshev bandpass filter in Ku-band.
Open Access
Design procedure for new compact waffle-iron ilters with transmission zeros
(IEEE, 2018) Teberio Berdún, Fernando; Percaz Ciriza, Jon Mikel; Arregui Padilla, Iván; Martín Iglesias, Petronilo; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Arnedo Gil, Israel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
In this paper, a novel waffle-iron filter with transmission zeros at multiple frequencies, along with its design procedure, is presented. The proposed filter features a high-power behavior and a wide rejected band in a single compact structure by means of a set of transmission zeros that can also be placed close to the passband. Its design method rests on a divide-and-rule strategy, where the physical dimensions of the constituent design entities (DEs) can be easily computed in a very short time. A novel high-power compact waffle-iron filter with transmission zeros at multiple frequencies has been designed as well as several classical waffle-iron filters with transmission zeros at one frequency only, using a detailed step-by-step procedure which avoids the bruteforce optimizations needed until now. Multipactor and corona simulations have been conducted proving a high-power handling capability of 1.8 kW and 78.6 W, respectively. A prototype of the novel filter has been fabricated, obtaining a remarkable accordance between the simulated and measured results.
Open Access
High-power filter design in waveguide technology: future generation of waveguide satellite filters in payloads handling increasing bit rates and numbers of channels
(IEEE, 2020) Arregui Padilla, Iván; Teberio Berdún, Fernando; Arnedo Gil, Israel; Percaz Ciriza, Jon Mikel; Martín Iglesias, Petronilo; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
To design a filter for a particular application, many issues must first be considered. Which technology will be the most convenient? What design technique will provide better results for a particular set of frequency specifications? Once the device has been designed, will it fulfill all of the (not only electrical) requirements? It is not always easy to answer such questions in advance. In this article, we try to shed some light on these questions when our aim is the design of filters for high-power operation.
Open Access
Compact harmonic rejection filter for C-band high-power satellite applications
(IEEE, 2020) Teberio Berdún, Fernando; Martín Iglesias, Petronilo; Arregui Padilla, Iván; Arnedo Gil, Israel; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
A compact high-power low-pass filter for C-band broadband satellite applications is presented in this paper. The filter is composed of three different sections. A 9th-order compact high-power multi-ridge structure achieves the fundamental mode stopband and the suppression of all-higher order modes. The required slope between the pass- and the stopband is accomplished by means of two step-shaped bandstop elements separated by very short waveguide sections. The passband of the filter is achieved through two compact matching networks. The filter is only 164-mm long, has less than 0.05 dB of insertion loss, handles 9.6 kW (single-carrier multipactor analysis), and has a very wide stopband (up to Ku-band). A dramatic size reduction has been achieved with respect to other commercially available solutions.
Open Access
General synthesis of tapered matching sections for single mode operation using the coupled-mode theory
(IEEE, 2019) Percaz Ciriza, Jon Mikel; Arnedo Gil, Israel; Arregui Padilla, Iván; Teberio Berdún, Fernando; Martín Iglesias, Petronilo; Gómez Laso, Miguel Ángel; Lopetegui Beregaña, José María; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
In this paper, a novel and general method to synthetize microwave waveguide tapers intended for single mode operation is proposed. The technique is based on the use of an exact series solution of the inverse scattering synthesis problem. An additional strategy necessary for dealing with waveguides where the propagation constant varies with the position is included. The coupled-mode theory is employed to model the electromagnetic behavior of the taper with the inherent mismatch caused by the connection of the waveguides with different cross-sections. The novel method allows us to synthesize the (classical) transmission line taper functions of Klopfenstein and Hecken, making them suitable for general waveguide tapers with single mode operation. Additionally, a new type of taper functions, also suitable for general waveguide tapers, is presented. The novel functions are obtained by partially employing the frequency response of multisection transformers, resulting in fully smooth tapers that can offer shorter lengths than the classical proposals. The taper synthesis procedure is demonstrated in rectangular waveguide technology, by requiring realistic and challenging specifications for different cases with different waveguide cross-sections to be matched: height mismatch, width mismatch, and simultaneous height and width mismatch. Several prototypes of Klopfenstein, Hecken and novel function tapers have been fabricated in an aluminum alloy by means of an Additive Manufacturing technique (Direct Metal Laser Sintering). The simulation and measurement results obtained for the rectangular waveguide taper prototypes confirm the accuracy of the novel synthesis technique proposed.