Open Access
Novel design method for millimeter-wave gap waveguide low-pass filters using advanced manufacturing techniques
(IEEE, 2023) Santiago Arriazu, David; Gómez Laso, Miguel Ángel; Lopetegui Beregaña, José María; Arregui Padilla, Iván; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
In this paper, a groove gap waveguide (GGW) low-pass filter is proposed for the first time. Gap waveguide technology represents an interesting alternative as a low-loss, cost-effective, high- performance transmission line and packaging solution for microwave and millimeter-wave systems. This technology may exhibit a frequency behavior similar to rectangular waveguide but with some advantages such as the no need of electrical contact between the upper and lower plates of the GGW, making it an attractive alternative in the design of satellite devices at high frequencies. However, all the previous literature focused on band-pass filters, while design methods for GGW low-pass filters have not been reported. Furthermore, in this paper a new manufacturing approach is proposed and its performance has been compared with traditional methods such as Computer Numerical Control (CNC) milling. The new approach relies on the Selective Laser Melting (SLM)-3D printing of the filter followed by a post-processing step, in which it is partially mechanized using CNC milling to improve the surface finish. Measurements of the manufactured prototypes are also included to compare both techniques at millimeter-waves, showing the advantages of the new fabrication method and the excellent agreement with the simulations.
Open Access
Metal 3D printing for RF/microwave high-frequency parts
(Springer, 2022) Martín Iglesias, Petronilo; Gómez Laso, Miguel Ángel; Lopetegui Beregaña, José María; Teberio Berdún, Fernando; Arregui Padilla, Iván; Marechal, M.; Calves, P.; Hazard, M.; Pambaguian, L.; Brandao, A.; Rodríguez Castillo, S.; Martin, T.; Percaz Ciriza, Jon Mikel; Iza, V.; Martín-Iglesias, Santiago; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Space Systems have been historically characterised by high performance, high reliability and high cost. Every new generation of space systems tends to improve performance, keep as much as possible reliability, speeding the lead time and lower the cost. Aggressive approach is nowadays followed by some of the players of the new space ecosystem where, for instance, reli- ability can be relaxed thanks for the in-orbit redundancy or robustness to failures by having a constellation with a high number of satellites. This push towards the technology and system limit requires to investigate new methods for the manufacturing of RF/Microwave parts. RF devices such as those based on waveguide structures, benefit from an additive manufacturing approach in terms of radio frequency (RF) performance and compactness. However each manufacturing approach comes with specific features and limitations which need to be well understood and, in some cases, even taking advantage of them. This paper provides a short review of some of the RF/Microwave parts already manufactured using this technology. The paper will focus mainly on metal 3D printing parts since this technology is, at the moment, well accepted by the space community.
Open Access
Wideband channel modeling for mm-wave inside trains for 5G-related applications
(Hindawi / Wiley, 2018) Moreno García-Loygorri, Juan; Briso Rodríguez, César; Arnedo Gil, Israel; Calvo, César; Gómez Laso, Miguel Ángel; He, Danping; Jiménez, Florentino; González Posadas, Vicente; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Passenger trains and especially metro trains have been identified as one of the key scenarios for 5G deployments. The wireless channel inside a train car is reported in the frequency range between 26.5GHz and 40GHz. These bands have received a lot of interest for high-density scenarios with a high-traffic demand, two of the most relevant aspects of a 5G network. In this paper we provide a full description of the wideband channel estimating Power-Delay Profiles (PDP), Saleh-Valenzuela model parameters, time-of-arrival (TOA) ranging, and path-loss results.Moreover, the performance of an automatic clustering algorithm is evaluated. The results show a remarkable degree of coherence and general conclusions are obtained.
Open Access
Cavity-stacked filter in CLAF-SIW technology for millimeter waves
(Elsevier, 2025-03-01) Segura-Gómez, Cleofás; Biedma-Pérez, Andrés; Santiago Arriazu, David; Palomares-Caballero, Ángel; Arregui Padilla, Iván; Gómez Laso, Miguel Ángel; Padilla, Pablo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
This work presents the design of a cavity-stacked bandpass filter (BPF) using contactless air-filled substrate integrated waveguide (CLAF-SIW) technology for millimeter-wave frequencies. This technology is a variant of air-filled SIW technology, incorporating contactless techniques. It enables the reduction of dielectric losses in SIW filters while supporting multilayer structures with robust assembly. The cavity-stacked filter topology allows for very good frequency responses with a reduced footprint and no transitions needed. As an example, a 4th-order Chebyshev bandpass filter composed of four stacked cavities, coupled through irises, is shown. The iris layers are fabricated by metallizing the slot edges of a PCB, while the cavity layers are implemented using CLAF-SIW. The filter has been designed and manufactured to provide a passband response from 36 GHz to 37.5 GHz. A good agreement between measurement and simulation has been achieved. The losses in the proposed CLAF-SIW filter are primarily due to the metal roughness of the low-cost commercial laminates used.
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
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
Robust and flexible design for effective low-pass filters exploiting a passband replica
(IEEE, 2024) Santiago Arriazu, David; Gómez Laso, Miguel Ángel; Lopetegui Beregaña, José María; Arregui Padilla, Iván; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
In this paper, a design approach for effective low-pass filters (LPF) that use the Rth-passband replica of the stepped-impedance prototype response is presented. Traditional LPF design methods often rely on well-established techniques, but they may not always deliver the desired performance or flexibility. By incorporating the Rth-passband replica of the stepped-impedance prototype, we introduce a new perspective that opens up new possibilities in filter design. This approach has the potential to overcome some of the limitations associated with existing methods, offering improved filter performance, robustness, and novel design possibilities and flexibility. Additionally, we will showcase its practical application by designing, fabricating, and measuring a 5th-order gap waveguide LPF that employs the first replica as per the provided guidelines.
Open Access
Caracterización de composites magneto-dieléctricos usando sensores resonantes de microondas y redes neuronales
(Universidad de Castilla La Mancha, 2024) Álvarez Botero, Germán Andrés; Lobato-Morales, Humberto; Hui, Katherine; Tarabay, Naji; Sánchez-Vargas, Jeu; Méndez-Jerónimo, Gabriela; Pons Abenza, Alejandro; Arregui Padilla, Iván; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Vélez, Camilo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako Gobernua
In this paper, we introduce an innovative approach for determining the complex permittivity (ε) and permeability (𝜇)) of magnetodielectric composites. Our methodology uses artificial neural network (ANN) modeling to determine these key parameters from S-parameter data collected at 2.45 GHz. These measurements are performed by a novel microstrip split ring resonator (SRR)-based resonant sensor, offering enhanced precision and reliability in the estimation process.
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
Diseño de filtro en guía de onda en banda W mediante guía multicapa con simetría glide
(URSI, 2023) García-Martínez, Sergio; Santiago Arriazu, David; Tamayo-Domínguez, Adrián; Sánchez-Olivares, Pablo; Arregui Padilla, Iván; Lopetegui Beregaña, José María; Fernández González, J. M.; Gómez Laso, Miguel Ángel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
Este artículo presenta el diseño e implementación de un filtro paso banda de cuarto orden en tecnología de guía de onda multicapa a 100 GHz. Para evitar fugas de campo en las paredes de la guía y permitir la implementación del filtro en múltiples capas sin necesidad de contacto eléctrico, se ha utilizado una estructura periódica con agujeros y simetría de deslizamiento, con agujeros circulares, como una estructura de banda prohibida electromagnética (EBG). Se presenta un filtro robusto y compacto, capaz de mantener una buena respuesta en la banda para un amplio rango de entrehierro entre capas. Este enfoque permite la implementación de la estructura compleja del filtro en bandas milimétricas, ofreciendo alta precisión y facilidad de fabricación.