Comunicaciones y ponencias de congresos DIEC - IEKS Biltzarretako komunikazioak eta txostenak
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Publication Open Access Lithography-free perfect narrowband absorbers using simple layered structures(IEEE, 2024-10-08) Lezaun Capdevila, Carlos; Navajas Hernández, David; Liberal Olleta, Íñigo; Beruete Díaz, Miguel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCLight absorbers are key components for multiple applications ranging from heat and energy management to communications and sensing. This work explores different complex permittivity combinations for material-reflector and material-spacer-reflector configurations, achieving perfect absorption under different permittivity regimes and thicknesses. Using silicon carbide, we discuss polarization and angle dependencies, and the potential of exploiting different permittivity regimes within a device for multi-band absorption. This work helps standardize absorber design and offer insights to engineer perfect absorbers for applications such as thermal emission, absorption, communication and sensing.Publication Open Access Perfect narrowband absorbers using simple lithography-free structures(IEEE, 2024-10-08) Lezaun Capdevila, Carlos; Navajas Hernández, David; Liberal Olleta, Íñigo; Beruete Díaz, Miguel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCLight absorption is a key phenomenon for a variety of technologies [1]: radiative cooling, photovoltaics, sensing, communication and camouflaging are just a few examples. These applications demand scalable and compact devices that modulate their absorption spectra, usually engineered using cavities and/or periodic structures acting as resonators. Weak light matter interaction limits the absorption within ultra-compact devices, although epsilon-near-zero (ENZ) materials allows to greatly increase such interaction [2]. The lack of design standardization presents a big gap for designing absorbers. We present a thorough analysis of an arbitrary material on top of a PEC (perfect electric reflector) and a material separated by a spacer from the PEC. We overview the absorption phenomena for different permittivity regions, thicknesses, angles of incidence and polarization. This work helps standardize the design of these absorber configuration.Publication Open Access Dielectric sensing of deeply subwavelength analytes using epsilon-near-zero waveguides(IEEE, 2024-10-08) Lezaun Capdevila, Carlos; Pacheco-Peña, Víctor; Beruete Díaz, Miguel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThe advent of metamaterials brought new wave-matter interaction paradigms to manipulate field and waves at will. Their applications are numerous: antennas, lenses, invisibility cloaking, computing, vortex beams and more. In turn, epsilon-near-zero (ENZ) metamaterials opened up new phenomena for light manipulation due to their exotic propagation constant, wavenumber and characteristic impedance. In 2008, it was demonstrated that a rectangular waveguide can emulate ENZ media by working near the cutoff frequency [1]. Moreover, the incredible field confinement inside the ENZ waveguide provided interesting features for sensing applications [2]. Our work further develops the idea of a dielectric body sensor based on a ENZ waveguide by considering an analyte partially filling the waveguide [3] and demonstrating empirically the setup [4].Publication Open Access Ultra-low detection limit lossy mode resonance-based fibre-optic biosensor(Optica Publishing Group, 2018) Chiavaioli, Francesco; Zubiate Orzanco, Pablo; Del Villar, Ignacio; Ruiz Zamarreño, Carlos; Giannetti, Ambra; Tombelli, Sara; Trono, Cosimo; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Baldini, Francesco; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCWe report on ultra-low detection limit lossy mode resonance-based fibre-optic biosensor coated with nm-thick tin dioxide film, which allows measuring fibre-surrounding medium changes with very high sensitivity for label-free and real-time biomolecular interaction analysisPublication Open Access Short single strand DNA detection by means of Lossy Mode Resonance based fiber-optic sensor(IEEE, 2019-01-14) Zubiate Orzanco, Pablo; Ciáurriz Gortari, Paula; Tellechea Malda, Edurne; Santano Rivero, Desiree; Del Villar, Ignacio; Urrutia Azcona, Aitor; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ruiz Zamarreño, Carlos; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA26Development of DNA and RNA biosensors and the associated diagnostic tests have gained growing interest in recent years. In particular, short RNA chains (around 25 oligonucleotides), known as micro RNAs, can be associated different stroke and neurodegenerative diseases. Here, we present the utilization of highly sensitive fiber optic sensor based on Lossy Mode Resonance (LMR) for the detection of single strand complementary DNA (ssDNA) associated to Huntington disease (Hsa-miR-34b).Publication Open Access A wide beamwidth magneto-electric dipole atenna for wide beam scanning antenna arrays(IEEE, 2024-09-30) Khan, Ihtesham; Zhao, Huiling; Iriarte Galarregui, Juan Carlos; Ederra Urzainqui, Íñigo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio IngeniaritzaIn this study, a simple and cost-effective configuration to broaden the beamwidths of the patch antenna has been studied. The proposed wide beamwidths antenna consists of two parasitic magnetic dipoles placed orthogonally to a driven electric dipole. Due to the complementary far-field radiation behaviors of both antennas in their respective E-plane and H-plane, the antenna half-power beamwidth broadens. An excellent wide beam of 138.6° and 110.9° in E-plane and H-plane, respectively, has been achieved at 4.72 GHz. The proposed antenna has been fabricated and tested. Measurements shows good agreement with the simulations. The proposed antenna can find its application for the increasing the scanning coverage of the patch antenna arrays.Publication Open Access Exploring surface roughness in epsilon-near-zero materials(IEEE, 2024-10-08) Navajas Hernández, David; Pérez Escudero, José Manuel; Liberal Olleta, Íñigo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThe practical application of materials with epsilon-near-zero (ENZ) characteristics heavily depends on the quality of real-world ENZ materials, considering factors like material losses and surface roughness. These materials have drawn interest due to their strong nonlinear responses and unique behavior. In this study, an experimental examination of how surface roughness affects ENZ substrates is presented. We employed silicon carbide (SiC) substrates deliberately engineered to exhibit different levels of roughness, enabling us to analyze samples spanning from a few to hundreds of nanometers in size scales. Substrates with nanoscale roughness experience adverse effects due to longitudinal phonon coupling and strong ENZ fields, while at larger roughness scales, the ENZ band demonstrates to be more robust compared to dielectric and surface phonon polariton (SPhP) bands.Publication Open Access Impact of diffraction on terahertz compressed sensing single-pixel imaging(IEEE, 2024) Ndagijimana, Adolphe; Ederra Urzainqui, Íñigo; Heredia Conde, Miguel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio IngeniaritzaTerahertz (THz) single-pixel imaging, through compressive sensing, enables sampling below Nyquist rates and bypasses the need for mechanical scanning and the limitation of availability of high-resolution cost-effective THz imaging array detectors off-the-shelf. This research investigates how diffraction phenomena affect THz single-pixel imaging and properties of sensing matrices, along with the sparse signal reconstruction process. We introduce a variety of strategies designed to mitigate the effects of diffraction, along with novel methods to counteract the disruptions caused by THz physics, thereby preserving the integrity of the original sensing matrix and improving signal recoverability. A comprehensive simulation study sheds light on the effects of diffraction on the sensing matrices and their impact on signal reconstruction. Our results highlight the importance of accurate diffraction minimization techniques and sophisticated modelling in enhancing THz imaging systems.Publication Open Access Symmetries in time-varying media: on the conservation of spin angular momentum, helicity, and chirality(IEEE, 2024) Mohammadi Jajin, Mohsen; Vázquez Lozano, Juan Enrique; Liberal Olleta, Íñigo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCOur results demonstrate that time-varying media exacerbate the differences between the symmetries and conserved quantities associated with dynamical properties associated with the circular polarization of light. In this manner, we provide further insights into the physical meaning of helicity and chirality, including their similarities and differences, as well as the fundamental role played by the symmetries of the electromagnetic Lagrangian in time-varying media.Publication Open Access Gain of bifacial PV modules on horizontal single-axis trackers in desert climates(IEEE, 2024-11-15) Parra Laita, Íñigo de la; García Solano, Miguel; Marcos Álvarez, Javier; Marroyo Palomo, Luis; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA2023-11389Over the last few years, the demand for bifacial PV modules has continuously increased. However, there are still some aspects regarding their outdoor performance under real conditions that need further investigation. This paper analyzes the bifacial PV modules gain obtained over one year in a horizontally tracked PV power plant located in the Atacama Desert, Chile. The study was carried out over the course of a year for two different types of trackers: a standard tracker as used in the rest of the plant and a tracker that, according to the manufacturer, is specially designed to maximize the production of the bifacial modules. The results show that bifacial PV modules with a conventional tracker are able to gain approximately a 5% in terms of both radiation and production whereas the bifacial PV modules mounted on the special bifacial tracker can gain up to 5.8% and 6.1 % respectively.Publication Open Access A Fabry-Perot cavity antenna with a SiGe on-chip feeder for submm-wave applications(IEEE, 2024-09-30) Khan, Ihtesham; Herrera-Martín, Juan M.; Urain, Álvaro; Iriarte Galarregui, Juan Carlos; Teniente Vallinas, Jorge; Ederra Urzainqui, Íñigo; Berenguer, Roc; González Posadas, Vicente; Segovia-Vargas, Daniel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThis paper analyzes the performance of a Fabry-Perot cavity antenna fed by an on-chip spiral antenna and compares it with an on-chip antenna designed to be integrated in IHP's 130nmSiGe BiCMOS chip in a 2 × 2 array configuration. The results show the increase in directivity obtained by the combination of the Fabry-Perot cavity and a single spiral antenna versus the directivity obtained by forming a complex sequentially rotated 2 × 2 spiral array.Publication Open Access Partially coated long period fiber Bragg gratings in multicore optical fibers(Optica, 2018) Barrera, David; Goicoechea Fernández, Javier; Madrigal, Javier; González Larequi, Marta; Arregui San Martín, Francisco Javier; Sales, Salvador; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCMulticore optical fibers (MCFs) have attracted considerable interest in the last years due to their potential in many applications including broadband communications, microwave photonics, and optical sensing [1,2]. In optical sensing, MCFs has been used in the past for implementing curvature and shape sensors [3]. However, the potential of MCFs for optical sensing is not limited to mechanical sensors and they can be used for implementing other types of sensors. In this paper, we investigate the use of MCFs for external refractive index (RI) sensing. We use LPGs inscribed in the cores of the fiber to detect changes in the external refractive index. Partially coating the surface of the optical fiber we can modify the sensitivity of the cores.Publication Open Access Liquid crystals in reconfigurable reflectarray antennas for sub-millimeter waves(IEEE, 2024-08-21) Pérez Quintana, Dayan; Aguirre Gallego, Erik; Olariaga Jauregui, Eduardo; Kuznetsov, Sergei A.; Lapanik, Valeri I.; Sutormin, Vitaly S.; Zyryanov, Victor Ya; Marcotegui Iturmendi, José Antonio; Beruete Díaz, Miguel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCAccelerated technological progress responds to the dynamic evolution of wireless communication systems, fueled by the advent of 5G, the emergence of 6G, and the pervasive integration of the IoT paradigm. Smart antennas play a pivotal role in this advancement, facilitating electronic beam steering to meet escalating demands for enhanced bandwidth and elevated operating frequencies. The spotlight shifts to reconfigurable reflectarray antennas, gaining prominence over conventional phased arrays. Notably, liquid crystals (LCs) emerge as a promising avenue for creating electronically reconfigurable/switchable reflectarrays, specifically tailored for short millimeter and terahertz waves. LCs, as a unique aggregate state combining solid and liquid features, address current technology limitations. Their uniaxial nature and the ability to manipulate molecule orientation enable effective fine-tuning of dielectric permittivity without drawbacks present in existing technologies.Publication Open Access Integration of wind and PV power in the spanish electric system using existing hydroelectric power(IEEE, 2024-08-30) Garwa, Asheem; Pascual Miqueleiz, Julio María; Marroyo Palomo, Luis; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThis paper analyses the potential reduction of electric energy generated with fossil fuels with 40 GW of PV power and 40 GW of wind power in the existing Spanish electric system and its integration by making use of existing hydroelectric power and reserves with different levels of flexibility. We use 10-minute data for 2 years and we firstly assume that hydro power remains the same as originally, observing an already high reduction in fossil fuel use in the electric mix. Then we increasingly allow more flexibility in hydro power use, i.e., we allow to use hydro reserves with different time horizons, and we analyze the incremental reduction in fossil fuel generation as we increase this flexibility. We observe that we can obtain notable gains in terms of fossil fuel reduction when increasing flexibility just slightly showing how hydro power can integrate large amounts of variable renewable energy in Spain with only a small change in the reserves profile.Publication Open Access Optimizing graphene oxide saturable absorbers for short pulse generation in fiber lasers: characterization and aging assessment(SPIE, 2024-06-20) Monteiro, Catarina S.; Pérez Herrera, Rosa Ana; Silva, Nuno A.; Silva, Susana; Frazão, Orlando; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThe generation of short pulses in fiber lasers using saturable absorbers made of graphene oxide (GO), focusing on film thickness, was studied and optimized. The saturable absorber comprised a GO thin film deposited onto a single-mode fiber using the spray coating technique. Water-dispersed GO with a concentration of 4 mg/mL, characterized by a high proportion of monolayer flakes, was employed. This thin film was integrated into a cavity ring laser featuring an erbium-doped fiber amplifier (EDFA), resulting in a fiber laser emitting at a central emission wavelength of approximately 1564 nm and having a total cavity length of approximately 120 m. By controlling intracavity polarization, short-pulsed light was generated through mode-locking, Q switching, or a combination of both regimes. This work presents a comprehensive characterization of the cavity ring laser operating under the mode-locking regime. It encompasses an analysis of the spectral behavior, focusing on the evolution of the Kelly¿s sidebands with increasing pump power, as well as an assessment of its temporal stability. Moreover, the effects of the aging of the saturable absorber material were studied after a time period of 6 months after the fabrication. It was observed that the general characteristics of spectral signal of the laser were maintained, with long-term stability.Publication Open Access Detection of wind turbine gearbox oil degradation with etched single-mode multimode single-mode (SMS) fiber(Optica, 2018) Del Villar, Ignacio; Goñi Carnicero, Jaime; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako GobernuaThe application of an etching process in a single-mode multimode single-mode (SMS) fiber allows monitoring the change of refractive index of wind turbine gearbox oil due to temperature and degradation. The SMS was designed for operating at short wavelengths, where the setup is less expensivePublication Open Access Thin film coated D-shaped fiber regenerable biosensor(Optica, 2020) Santano Rivero, Desiree; Ciáurriz Gortari, Paula; Tellechea Malda, Edurne; Zubiate Orzanco, Pablo; Socorro Leránoz, Abián Bentor; Del Villar, Ignacio; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCWe present a novel covalent functionalization of a D-shape fiber biosensor based on Lossy Mode Resonances. IgG/anti-IgG model is applied to prove the regeneration of the union and thus the re-usability of the sensor.Publication Open Access Analog electronics projects to encourage active learning(IEEE, 2024-08-01) Escribano Simón, Leyre; Tainta Ausejo, Santiago; Erro Betrán, María José; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PINNE2022-UPNAIn this work we present a proposal to include Project Based Learning (PBL) in an Analog Electronics course. For this purpose, several projects have been developed to be implemented in an advanced degree course, covering advanced concepts related to amplifiers, oscillators, and active filters. The results obtained after the rollout of one of these projects in an Industrial Engineering degree course are reported.Publication Open Access Optical gateway for intelligent buildings: a new open-up window to the optical fibre sensors market?(SPIE, 2004-06-09) Fernández Valdivielso, Carlos; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Bariáin Aisa, Cándido; López-Amo Sáinz, Manuel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako GobernuaThis paper presents the first optical fibre sensor gateway for integrating these special measurement devices in Home Automation Systems, concretely in those buildings that use the KNX European Intelligent Buildings Standard.Publication Open Access Experimental teaching of digital PID controllers(IEEE, 2024-08-01) Tainta Ausejo, Santiago; Cruz Blas, Carlos Aristóteles de la; Cid Monjaraz, Jaime; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio IngeniaritzaPID controllers are a fundamental building block of industrial control systems. In this paper we present a simple demonstrator that can be assembled using basic electronic components and an Arduino UNO development board as plant and digital controller, respectively. The complete system can be easily built using components that are often available in a basic electronic lab, avoiding mechanical or electromechanical systems. The proposed system is open and flexible, allowing the study of digital PID control systems and the experimental evaluation of different tuning methods.