Grupos Investigadores

Miembros del Grupo

Estevez Hidalgo
Jafait Junior
Fodop Sokoudjou
Villa González
José Antonio

Líneas de Investigación

  • Diseño y caracterización de antenas
  • Fabricación de sensores
  • Sensores inalámbricos
  • Sensores inalámbricos RFID y chipless
  • Simulación y Caracterización electromagnética
  • Software y Hardware de instrumentación

Palabras Clave

  • Antenna design
  • Electromagnetic simulation
  • Hardware and software
  • Instrumentation
  • Wireless chipless sensors
  • Wireless RFID sensors

Publicaciones Científicas desde 2018

  • Autores: Estévez, A. (Autor de correspondencia); Pérez Hernández, Noemí; Valderas Gázquez, Daniel; et al.
    ISSN: 2076-3417 Vol.13 N° 7 2023 págs. 4187
    The present work describes a new approach for the design of a Frequency-Selective Surface (FSS) in the context of frequency filters to increase isolation between two vehicle-borne antennas. A compact FSS design based on nested square meandered resonators is optimized for multifrequency operation. Furthermore, a design workflow is proposed. In general, the measurement of low-profile FSS does not correspond to simulation through Floquet modes based on periodic boundary conditions due to the lack of uniformity of mutual coupling among the FSS unit cells. The proposed method demonstrates the agreement between the infinite simulation and the measurement of the finite prototype once a convenient scale factor is applied, which facilitates the design workflow. In this case, an FSS is used as an efficient filter to increase the isolation between antennas by 6 dB in three representative bands (3GPP, WiFI I and II). In this way, multifrequency antennas can be placed at approximately half their actual distance with the same performance in spatial-constrained vehicular environments.
  • Autores: Valderas Gázquez, Daniel (Autor de correspondencia); Villa González, Fatima; Bhattacharyya, Rahul; et al.
    ISSN: 1530-437X Vol.23 N° 17 2023 págs. 19028 - 19036
  • Autores: Villa Gonzalez, Fatima (Autor de correspondencia); Rezola Garciandía, Ainhoa; del Río Orduña, David; et al.
    ISSN: 0018-9456 Vol.72 2023 págs. 1-14
    This article presents a high-performance frequency-domain chipless RFID reader with vector background subtraction capabilities, implemented in a software-defined radio (SDR) for the first time. The proposed reader is low-cost, compact size, and versatile. It is implemented in a USRP N210 paired to a modified CBX-40 daughterboard, enabling magnitude and phase data acquisition in a monostatic (one antenna) set up. The reader can perform a vector background subtraction operation between two complex measurements (with and without a chipless tag) to suppress the self-interference (SI) that hinders the response of the tag and provide 40 dB of dynamic range. To demonstrate the performance of the reader, the spectral signatures of three frequency-coded (FC) tags with four resonant frequencies are captured over the 1.5-4-GHz band scanned with 10-MHz resolution in 251 ms, obtaining comparable measurements to those of an expensive laboratory vector network analyzer (VNA) from 20 to 40 cm. The detected resonant frequency offset between both devices is Delta f(r) <= 4.18% . It is also demonstrated that the proposed reader can track a resonant frequency shift and therefore be used in real-time sensing applications.
  • Autores: Estévez, Ailyn (Autor de correspondencia); Fofop Sokoudjou, Jafait Junior; Sancho Seuma, Juan Ignacio; et al.
    ISSN: 1530-437X Vol.23 N° 18 2023 págs. 21234 - 21245
    Temperature monitoring is essential in several industries driving the need for sensors. Chipless radio frequency identification (RFID) technology has emerged as a cost-effective solution, enabling wireless detection without the need for a power supply or electronics embedded in the sensor tags. However, a significant challenge lies in wirelessly monitoring temperature within liquid environments using chipless RFID tags as resonances vanish due to energy absorption in liquids. This work presents a chipless RFID sensor for wireless detection of oil temperature in a glass container. The temperature monitoring is based on the characterization of the permittivity of oil samples with different concentrations of total polar compounds (TPCs). After evaluating two chipless RFID tag designs, we propose to use a complementary ring resonator (CRR) tag as it exhibits a robust response to oil liquid volume, improving the detection of temperature in low-loss liquids and offering higher sensitivity. When the measurement results are coupled with machine learning (ML), we demonstrate that the response of the proposed tag as a wireless sensor can be used to estimate the temperature of oil samples with different quality (TPC) with an average test RMSE of 4 degrees C (standard deviation < 2 degrees C), in the approximate range 22 degrees C-95 degrees C.
  • Autores: Sancho Seuma, Juan Ignacio (Autor de correspondencia); Almandoz, I.; Barandiaran, M.; et al.
    ISSN: 0278-0046 Vol.69 N° 1 2022 págs. 1011 - 1020
    A scalable system for wireless wear monitoring in a distributed harsh industrial environment, in which installation of the electronic equipment near the distributed wearing measuring locations is unfeasible, has been successfully designed, developed and deployed. The system is composed of a novel LC-type passive wireless wear sensor system, a sensor readout coil, an electronic equipment, a readout unit for a scalable multisensor system and a control and monitoring system. The capacitor structure, employed as a sensing device in the LC sensor manufactured on low cost PCB, provides a linear response to the wear level. This allowed us to define a measuring and calibration method to suppress the cable effects from each distributed readout coil to the electronic equipment readout unit. It was possible to achieve a multiple simultaneous measurements in different sensors distributed along an industrial process without significant cabling influence. Concerning the sensor data analysis, a double Holt-Winters method with trend was used to reduce noise effects and an "experience based learning" tool was implemented in order to solve any misbehavior or time lag. Laboratory measurements and on-site operation results in an article mill indicate 1 mm precision and about 0, 5 MHz/mm sensitivity of the LC-type passive wireless wear sensor system.
  • Autores: Valderas Gázquez, Daniel (Autor de correspondencia); Sancho Seuma, Juan Ignacio; Benli, K.; et al.
    ISSN: 0018-9545 Vol.70 N° 6 2021 págs. 5592 - 5604
    This paper presents a model to anticipate the impact of Eddy Current Brakes (ECBs) installed in high-speed trains on the readouts of rail-side wheel sensors. The purpose is to anticipate false positive readouts of train wheels when traversing, one of the main obstacles for full ECB deployment. The ECB type EWB 154 from Knorr-Bremse and Wheel Sensor types RSR180 and RSR123 from Frauscher Sensor Technology are represented in a comprehensive model, integrating LTSpice and CST Microwave Studio. The wheel sensor predicted readout error is 4% compared to measurements when DC current is not applied to the ECB (passive case). It is demonstrated that the RSR180 is not compatible with ECBs, whereas the RSR123 is. The impact of active (DC current fed) brakes is analyzed when performing running tests with a high-speed ICE 3 train equipped with ECBs. The model is adjusted to study the saturation of the rail and ECB pole cores. The extra damping of the wheel sensor fingerprint is modeled by an extra 6% drop that may well be applicable to passive tests in a laboratory setting to shift to active tests without actually performing them. In this way, cost and time would be saved. Based on the model outcomes, a test bench is recommended for laboratory tests to emulate active behavior.
  • Autores: Ortego, I.; Rezola Garciandía, Ainhoa; Gao, Y.; et al.
    ISSN: 2076-3417 Vol.11 N° 13 2021 págs. 6032
    In this work, the optimum homogeneous phantom size for an equivalent whole-body electromagnetic (EM) modeling is calculated. This will enable the simple characterization of plane wave EM attenuation and far-field link budgets in Active Medical Implant (AMI) applications in the core region of the body for Industrial, Scientific, Medical and MedRadio frequency bands. A computational analysis is done to determine the optimum size in which a minimum phantom size reliably represents a whole-body situation for the corresponding frequency of operation, saving computer and laboratory resources. After the definition of a converge criterion, the computed minimum phantom size for subcutaneous applications, 0-10 mm insertion depth, is 355 x 160 x 255 mm(3) for 402 MHz and 868 MHz and a cube with a side of 100 mm and 50 mm for 2.45 GHz and 5.8 GHz, respectively. For deep AMI applications, 10-50 mm insertion depth, the dimensions are 355 x 260 x 255 mm(3) for 402 MHz and 868 MHz, and a cube with a side of 200 mm and 150 mm for 2.45 GHz and 5.8 GHz, respectively. A significant reduction in both computational and manufacturing resources for phantom development is thereby achieved. The verification of the model is performed by field measurements in phantoms made by aqueous solutions with sugar.
  • Autores: Villa, F. (Autor de correspondencia); Cortes, I.; Urain, A.; et al.
    ISSN: 1045-9243 Vol.61 N° 4 2019 págs. 90 - 96
    This article presents the design of a complete radio system receiver to detect, in real time, the direction of arrival (DOA) of an incoming industrial, scientific, and medical (ISM)-band signal at 5.8 GHz. When a transmitter continuously sends a binary phase-shift keying (BPSK), modulated pseudo-noise (PN) code, the receiver estimates the DOA based on the received signal strength (RSS) and performs the channel sounding. The device that we describe includes a pattern-reconfigurable monopole antenna array, a front end, and a systemon-module (SOM). The SOM controls the antenna's main lobe direction by positive-intrinsic-negative (p-i-n) diode switching, configures the front-end modules, completes the data acquisition, and performs the digital signal processing (DSP) for the DOA estimation. The system has an average DOA resolution of 90° in the horizontal plane, with a success rate higher than 90%. It is presented as an educational platform for electrical engineering undergraduate and M.S. degree students.
  • Autores: Sancho Seuma, Juan Ignacio (Autor de correspondencia); Pérez Hernández, Noemí; de Nó Lengaran, Joaquín; et al.
    Revista: SENSORS
    ISSN: 1424-8220 Vol.19 N° 23 2019 págs. 5183
    Inductor-capacitor (LC) passive wireless sensors are widely used for remote sensing. These devices are limited in applications where multiparameter sensing is required, because of the mutual coupling between neighboring sensors. This article presents two effective decoupling techniques for multiparameter sensing, based on partially overlapped sensors and decoupling coils, which, when combined, reduce the mutual coupling between sensors to near zero. A multiparameter LC sensor prototype with these two decoupling mechanisms has been designed, simulated, and measured. This prototype is capable of simultaneously measuring four parameters. The measurements demonstrate that the changes in capacitance in one individual sensor do not affect the measurements of the other sensors. This principle has been applied to simultaneous wear sensing using four identical wear sensors.

Proyectos desde 2018

  • Título: BEE-Building Energy Efficiency : Estimación precisa de la ocupación en edificios para una mejor gestión energética (Proyectos I+D)
    Código de expediente: 2023-CIEN-000050-01
    Investigador principal: DANIEL VALDERAS GAZQUEZ.
    Convocatoria: 2023 Programa de Red Guipuzcoana de Ciencia, Tecnología e Innovación
    Fecha de inicio: 18-04-2023
    Fecha fin: 30-09-2024
    Importe concedido: 72.896,00€
    Otros fondos: -
  • Título: WISTREM - Wireless Industrial Systems for Extreme Enviroments Investigación en sistemas inalámbricos para entornos hostiles de temperatura y físicos. Proyectos I+D Empresarial
    Código de expediente: 2022-CIEN-000081-01
    Investigador principal: DANIEL VALDERAS GAZQUEZ.
    Convocatoria: Programa Red Guipuzcoana de Ciencia, Tecnología e Innovación 2022
    Fecha de inicio: 05-05-2022
    Fecha fin: 04-05-2024
    Importe concedido: 53.159,00€
    Otros fondos: -
  • Título: Aislamiento entre antenas con metamateriales para comunicaciones inalámbricas multiestandar en vehículos - ISOLAN (Programa Red guipuzcoana de Ciencia, Tecnología e Innovación 2021)
    Código de expediente: 2021-CIEN-000105-01
    Investigador principal: NOEMI PEREZ HERNANDEZ.
    Convocatoria: Programa Red guipuzcoana de Ciencia, Tecnología e Innovación_DFG 2021
    Fecha de inicio: 09-06-2021
    Fecha fin: 01-10-2021
    Importe concedido: 77.528,00€
    Otros fondos: -
  • Título: Radiómetros avanzados en rango milimétrico para instrumentos de observación terrestre de nueva generación para predicción meteorológica y evaluación de cambio climático
    Código de expediente: PID2019-109984RB-C44
    Investigador principal: DANIEL VALDERAS GAZQUEZ.
    Convocatoria: 2019 AEI PROYECTOS I+D+i (incluye Generación del conocimiento y Retos investigación)
    Fecha de inicio: 01-06-2020
    Fecha fin: 01-01-2023
    Importe concedido: 106.117,00€
    Otros fondos: -