Open Access
Gap waveguide topology with reduced height pins for millimeter-wave components
(URSI Publications, 2022) 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
A new topology for groove gap waveguide (GGW) technology is proposed to ease its manufacturing process by computer numerical control (CNC) milling. GGW technology consists of two metal plates, where one of them presents a λ/4 height pin bed that avoids contact with the other plate, making it an ideal alternative to other waveguides for millimeterwave applications. However, the manufacture of the pins by CNC milling may be troublesome due to the large pin height required. A GGW with reduced height pins will be proposed, maintaining the standard dimensions of the equivalent rectangular waveguide ports and the operation bandwidth. The performance of this new topology will be compared with other proposals by means of simulations and measurements, and a bandpass filter will be also implemented and manufactured in this technology to validate its usefulness.
Open Access
W-band filtering antenna based on a slot array and stacked coupled resonators using gap waveguide technology
(IEEE, 2024) Santiago Arriazu, David; Fang, Mu; Zaman, Ashraf Uz; 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
This letter proposes a new design approach for filtering antennas. The novel matching reflection coefficient based method allows the integration of filters and antennas without compromising the frequency behavior of either of these components. Moreover, this integration is done avoiding the need of lengthy optimization processes and provides a high degree of flexibility in the types of antennas that can be used. In order to validate it, two examples are provided. In both cases, a 4 th -order Chebyshev bandpass filter at 101.5 GHz implemented in stacked groove gap waveguide (GGW) configuration is used, firstly along with a single aperture antenna and, subsequently, with a slotted ridge gap waveguide (RGW) array. This second example has been manufactured to demonstrate the usefulness of the new design methodology. Excellent measured performance has been obtained for a filtering antenna at W-band for the first time.
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
The Canfranc Axion Detection Experiment (CADEx): search for axions at 90 GHz with Kinetic Inductance Detectors
(IOP Publishing, 2022) Aja, Beatriz; Arguedas Cuendis, Sergio; Arregui Padilla, Iván; Artal, Eduardo; Barreiro, R. Belén; Casas, Francisco J.; Ory, Marina C. de; Díaz-Morcillo, Alejandro; Fuente, Luisa de la; Gallego, Juan Daniel; García-Barceló, José María; Gimeno, Benito; Gómez, Alicia; Granados, Daniel; Kavanagh, Bradley J.; Gómez Laso, Miguel Ángel; Lopetegui Beregaña, José María; Lozano-Guerrero, Antonio José; Magaz, María T.; Martín-Pintado, Jesús; Martínez-González, Enrique; Miralda-Escudé, Jordi; Monzó-Cabrera, Juan; Najarro de la Parra, Francisco; Navarro-Madrid, José R.; Núñez Chico, Ana B.; Pascual, Juan Pablo; Pelegrin, Jorge; Peña Garay, Carlos; Rodríguez, David; Socuéllamos, Juan M.; Teberio Berdún, Fernando; Teniente Vallinas, Jorge; Vielva, Patricio; Vila, Iván; Vilar, Rocío; Villa, Enrique; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
We propose a novel experiment, the Canfranc Axion Detection Experiment (CADEx), to probe dark matter axions with masses in the range 330–460 μeV, within the W-band (80–110 GHz), an unexplored parameter space in the well-motivated dark matter window of Quantum ChromoDynamics (QCD) axions. The experimental design consists of a microwave resonant cavity haloscope in a high static magnetic field coupled to a highly sensitive detecting system based on Kinetic Inductance Detectors via optimized quasi-optics (horns and mirrors). The experiment is in preparation and will be installed in the dilution refrigerator of the Canfranc Underground Laboratory. Sensitivity forecasts for axion detection with CADEx, together with the potential of the experiment to search for dark photons, are presented.
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
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
Improvement of corona breakdown threshold (peak power handling) in smooth-profiled microstrip filters
(2022) Ahmad, Jamil; Hussain, Jabir; Arregui Padilla, Iván; Martín Iglesias, Petronilo; Arnedo Gil, Israel; Gómez Laso, Miguel Ángel; Lopetegui Beregaña, José María; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
In this paper, the PPHCs of two filter design techniques, stepped-impedance (SI) and smooth-profile (SP), are presented for four design prototypes. Smooth-profiled filters feature smooth variations in the characteristic impedance profile, avoiding sharp edges, which accumulate electric fields. The absence of sharp edges in SP reduces the voltage magnification factor, which in turn improves the PPHC of the filter. The phenomenon of electric fields accumulation at the sharp corners of the SI filters is presented and compared with smooth transitions in SP filters. Furthermore, 1D graphs of electric field intensity are presented along the strip contour of the microstrip lines. Finally, SPARK3D results clearly demonstrate that SP filters can handle higher peak powers than their SI counterparts between critical pressure and ambient pressure, for all the studied designs.
Open Access
Synthesis of rectangular waveguide filters with smooth profile oriented to direct metal additive manufacturing
(IEEE, 2023) Percaz Ciriza, Jon Mikel; Hussain, Jabir; Arregui Padilla, Iván; Teberio Berdún, Fernando; Benito Pertusa, David; Martín Iglesias, Petronilo; Arnedo Gil, Israel; Gómez Laso, Miguel Ángel; Lopetegui Beregaña, José María; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
In this paper, a novel design method for rectangular waveguide filters intended for fabrication using direct metal additive manufacturing is proposed. The synthesized filters will feature a smooth profile that allows us to fabricate them orienting the filter propagation axis in the vertical building direction, achieving an optimum configuration for direct metal additive manufacturing fabrication. The novel design method is valid for any all-pole transfer function, which is initially implemented with a commensurate-line distributed unit element prototype. The impulse response of that initial prototype is then properly interpolated to obtain the target response for a smooth-profiled filter with similar length and profile excursion. Finally, the target impulse response just generated is implemented in rectangular waveguide technology employing a novel inverse scattering synthesis technique that relies on the coupled-mode theory to model the electromagnetic behavior of the waveguide filter. The novel inverse scattering synthesis technique is general and also valid for the case of filters with very high rejection levels, which is of great relevance in rectangular waveguide technology. A Ku-band low-pass filter with stringent satellite specifications is designed using the proposed method, fabricated by means of a direct metal additive manufacturing technique, and measured with a vector network analyzer. A very good agreement is achieved between the simulated and measured results, fulfilling the required specifications and demonstrating the feasibility and performance of the novel design method.
Open Access
Robust tolerance design of bandpass filter with improved frequency response for Q-band satellite applications
(IEEE, 2021) Sami, Abdul; Teberio Berdún, Fernando; Miranda Santafé, Luis; Arnedo Gil, Israel; Martín Iglesias, Petronilo; Benito Pertusa, David; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Arregui Padilla, Iván; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
A rectangular waveguide bandpass filter for Q-band with simple fabrication is proposed in this letter. The design is based on the use of the first passband replica of commensurate-line stepped-impedance structures and achieves the suppression of their inherent low-pass response. In order to do it, the filter is implemented by rectangular waveguide sections with different widths and heights that can be analytically calculated. The technique is validated by a 9th order Chebyshev filter with passband between 40 and 43 GHz and fabrication yield equal to 84 % for a manufacturing error of ± 20 μm. The measured results of the prototype fabricated with CNC milling are in good agreement with the simulated ones.
Open Access
Enhancement of the peak power handling capability in microstrip filters by employing smooth-profiled conductor strips
(2023) Ahmad, Jamil; Hussain, Jabir; Arregui Padilla, Iván; Martín Iglesias, Petronilo; Arnedo Gil, Israel; Gómez Laso, Miguel Ángel; Lopetegui Beregaña, José María; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
This paper presents a design methodology that significantly increases the peak power handling capability (PPHC) of microstrip filters. The PPHC is limited in microstrip technology by the corona effect: a physical phenomenon caused by the ionization of the air under the presence of strong electric fields around the planar circuit. Microstrip filters with a low electric field strength in the air increases the corona threshold level, resulting in high PPHC. Conventional stepped impedance (SI) filters, which consist of cascaded step-shaped elements, exhibit sharp discontinuities. These geometric edges amplify the electric field strength in the air, consequently reducing the corona threshold. Our research group has recently reported a new synthesis technique that introduces a smooth-profile (SP) conductor strip. This SP strip eliminates any sharp discontinuities and significantly reduces the strength of the electric field. This paper focuses on the examination of the high power performance of 7th-order SP and SI low-pass filters. The cut-off frequency (fc) for both types of filters is set at 447.45 MHz, while the frequency for maximum stop-band rejection (fo) is 1 GHz. The findings indicate that the SP filter shows a notable enhancement in peak power handling capability (PPHC), with gains of 2.48 dB and 4.80 dB observed at critical pressure and ambient pressure, respectively.