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
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
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
Synthesis of one dimensional electromagnetic bandgap structures with fully controlled parameters
(IEEE, 2017) Arnedo Gil, Israel; Chudzik, Magdalena; Percaz Ciriza, Jon Mikel; Arregui Padilla, Iván; Teberio Berdún, Fernando; Benito Pertusa, David; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, we propose a novel synthesis strategy for the design of one dimensional electromagnetic bandgap (1- D-EBG) structures where all the performance parameters of these devices can fully be controlled, i.e., the central frequency of the forbidden band, its attenuation level and bandwidth, and the ripple level at the passbands. The novel synthesis strategy employs a new inverse-scattering technique to accurately synthesize the 1-D-EBG structure, targeting a properly interpolated version of a classical periodic filter fulfilling the required frequency specifications. The new inverse-scattering technique follows a continuous layer peeling approach and relies on the coupled-mode theory to precisely model the microwave structures. Telecommunication and radar systems, as well as material characterization devices, will be profited by this proposal with which enhanced filters, sensors, power dividers, couplers, mixers, oscillators, and amplifiers can be designed in many different technologies. As a proof of concept, a 1-D-EBG structure in microstrip technology with a single forbidden band (free of spurious stopband replicas), with attenuation level of 30 dB, fractional bandwidth larger than 100%, and return loss level at the passbands of 20 dB, has been designed and fabricated. The measurements obtained are in very good agreement with the simulations and target specifications, being free of spurious replicas up to the 15th harmonic, showing the robustness and very good performance of the novel design strategy proposed.
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
Producing and exploiting simultaneously the forward and backward coupling in EBG-assisted microstrip coupled lines
(IEEE, 2016) Percaz Ciriza, Jon Mikel; Chudzik, Magdalena; Arnedo Gil, Israel; Arregui Padilla, Iván; Teberio Berdún, Fernando; Gómez Laso, Miguel Ángel; Lopetegui Beregaña, José María; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, a methodology is proposed for the design of EBG-assisted coupled line structures in microstrip technology, controlling independently the forward and backward coupling. It is based on the use of a single-frequency-tuned electromagnetic bandgap (EBG) structure to produce a single backward-coupled frequency band, in combination with the forward-coupled frequency bands produced by the difference between the even and odd mode propagation constants present in microstrip technology. Thus, the central frequency of the backward-coupled band is controlled by the period of the EBG structure, while the frequencies of the forward coupled bands are fixed by the length of the device. The rest of the frequencies go to the direct port giving rise to a device with the input port matched at all the frequencies and where the coupled bands are easily controllable by adjusting the corresponding design parameter. The novel methodology proposed has been successfully demonstrated by designing a triplexer intended for the GSM (900 MHz) and WLAN (2.4 GHz and 5.5 GHz) telecommunication bands.