• 3-D-printed transmit-array antenna for broadband backhaul 5G links at V-band 

      Matos, Sérgio A.; Teixeira, Jorge P.; Costa, Jorge R.; Fernandes, Carlos A.; Río Bocio, Carlos del Upna Orcid (IEEE, 2020)   Artículo / Artikulua  OpenAccess
      The low cost and compactness of transmit-array antennas (TAs) make them attractive for 5G backhaul links. However, the TA advantage is less obvious when considering the broadband operation requirement. Two main factors ...
    • 300 GHz optoelectronic transmitter combining integrated photonics and electronic multipliers for wireless communication 

      Ali, Muhsin; Pérez Escudero, José Manuel Upna Orcid; Guzmán Martínez, Robinson Cruzoe; Lo, Mu Chieh; Ederra Urzainqui, Íñigo Upna Orcid; Gonzalo García, Ramón Upna Orcid; García Muñoz, Luis Enrique (MDPI, 2019)   Artículo / Artikulua  OpenAccess
      THz communications systems at carrier frequencies above 200 GHz are the key to enable next-generation mobile communication networks with 100 Gbit/s wireless data rates. One of the key questions is, which carrier frequency ...
    • 360 nW gate-driven ultra-low voltage CMOS linear transconductor with 1 MHz bandwidth and wide input range 

      Rico-Aniles, Héctor Daniel; Ramírez-Angulo, Jaime; López Martín, Antonio Upna Orcid; González Carvajal, Ramón (IEEE, 2020)   Artículo / Artikulua  OpenAccess
      A low voltage linear transconductor is introduced. The circuit is a pseudo differential architecture that operates with ±0.2V supplies and uses 900nA total biasing current. It employs a floating battery technique to achieve ...
    • A 3D ray launching time-frequency channel modeling approach for UWB ranging applications 

      Otim, Timothy Upna; López Iturri, Peio Upna Orcid; Azpilicueta Fernández de las Heras, Leyre Upna Orcid; Bahillo, Alfonso; Falcone Lanas, Francisco Javier Upna Orcid (IEEE, 2020)   Artículo / Artikulua  OpenAccess
      Ultrawideband (UWB) has the ability to achieve decimetre level of ranging accuracy, hence, its wider usage nowadays in the field of positioning. In spite of the attractiveness of UWB, its performance is strongly dependent ...
    • 3D-ray launching MIMO channel geometric estimation 

      Rodríguez Corbo, Fidel Alejandro; Azpilicueta Fernández de las Heras, Leyre Upna Orcid; Celaya Echarri, Mikel Upna Orcid; Shubair, Raed M.; Falcone Lanas, Francisco Javier Upna Orcid (IEEE, 2022)   Artículo / Artikulua  OpenAccess
      The complete multiple-input–multiple-output (MIMO) channel simulation in deterministic techniques can be a computationally intensive task, due to the inherent scenario’s complexity and number of antennas. The spatial ...
    • 5G spatial modeling of personal RF-EMF assessment within aircrafts cabin environments 

      Celaya Echarri, Mikel Upna Orcid; Azpilicueta Fernández de las Heras, Leyre Upna Orcid; Rodríguez Corbo, Fidel Alejandro; López Iturri, Peio Upna Orcid; Shubair, Raed M.; Ramos González, Victoria; Falcone Lanas, Francisco Javier Upna Orcid (IEEE, 2022)   Artículo / Artikulua  OpenAccess
      Recently, new wireless communication systems within aircrafts cabins have drawn higher attention due to the growing demand of passenger services and applications and their corresponding requirements and constraints. In ...
    • 60 GHz single-layer slot-array antenna fed by groove gap waveguide 

      Ferrando Rocher, Miguel; Valero Nogueira, Alejandro; Herranz Herruzo, José I.; Teniente Vallinas, Jorge Upna Orcid (IEEE, 2019)   Artículo / Artikulua  OpenAccess
      A V-band single-layer low-loss slot-array antenna is presented in this letter. Radiating slots are backed by coaxial cavities, which are fed through a groove gap waveguide E-plane corporate feed network. Cavity resonances ...
    • AC amplifiers with ultra-low corner frequency by using bootstrapping 

      Martincorena Arraiza, Maite Upna Orcid; Carlosena García, Alfonso Upna Orcid; Cruz Blas, Carlos Aristóteles de la Upna Orcid; López Martín, Antonio Upna Orcid (Institution of Engineering and Technology, 2021)   Artículo / Artikulua  OpenAccess
      A novel architecture for an AC (i.e. high-pass) amplifier is proposed allowing a drastic reduction of the cutoff frequency to the sub-Hertz range. It builds upon the classic AC configuration with a high gain amplifier and ...
    • AC coupled amplifier with a resistance multiplier technique for ultra-low frequency operation 

      Martincorena Arraiza, Maite Upna Orcid; Cruz Blas, Carlos Aristóteles de la Upna Orcid; Carlosena García, Alfonso Upna Orcid; López Martín, Antonio Upna Orcid (Elsevier, 2022)   Artículo / Artikulua  OpenAccess
      This paper proposes a novel, tunable AC coupled capacitive feedback amplifier, exhibiting an ultra-low high pass corner frequency. This is accomplished by actively boosting the output resistive value of a MOS transistor ...
    • Accurate pupil center detection in off-the-shelf eye tracking systems using convolutional neural networks 

      Larumbe Bergera, Andoni Upna Orcid; Garde Lecumberri, Gonzalo Upna; Porta Cuéllar, Sonia Upna Orcid; Cabeza Laguna, Rafael Upna Orcid; Villanueva Larre, Arantxa Upna Orcid (MDPI, 2021)   Artículo / Artikulua  OpenAccess
      Remote eye tracking technology has suffered an increasing growth in recent years due to its applicability in many research areas. In this paper, a video-oculography method based on convolutional neural networks (CNNs) for ...
    • Addressing the impact of surface roughness on epsilon-near-zero silicon carbide substrates 

      Navajas Hernández, David Upna; Pérez Escudero, José Manuel Upna Orcid; Martínez Hernández, María Elena Upna Orcid; Goicoechea Fernández, Javier Upna Orcid; Liberal Olleta, Íñigo Upna Orcid (American Chemical Society, 2023)   Artículo / Artikulua  OpenAccess
      Epsilon-near-zero (ENZ) media have been very actively investigated due to their unconventional wave phenomena and strengthened nonlinear response. However, the technological impact of ENZ media will be determined by the ...
    • Advanced graphene-based transparent conductive electrodes for photovoltaic applications 

      Fernández, Susana; Boscá, Alberto; Pedrós, Jorge; Inés Ortigosa, Andrea; Fernández Vallejo, Montserrat Upna; Arnedo Gil, Israel Upna Orcid; González, José Pablo (MDPI, 2019)   Artículo / Artikulua  OpenAccess
      New architectures of transparent conductive electrodes (TCEs) incorporating graphene monolayers in different configurations have been explored with the aim to improve the performance of silicon-heterojunction (SHJ) cell ...
    • Advances in fiber optic DNA-based sensors: a review 

      Santano, Desiree Upna Orcid; Urrutia Azcona, Aitor Upna Orcid; Ruiz Zamarreño, Carlos Upna Orcid; Del Villar, Ignacio Upna Orcid (IEEE, 2021)   Artículo / Artikulua  OpenAccess
      DNA is becoming increasingly important in the domain of optical fiber sensors, either as a tool for biosensing, or as a target to detect. In this review the main contributions of the last years are presented both in the ...
    • Ag@Fe3O4-coated U-shaped plastic optical fiber sensor for H2S detection 

      López Vargas, Juan David; Dante, Alex; Allil, Regina C.; Del Villar, Ignacio Upna Orcid; Matías Maestro, Ignacio Upna Orcid; Werneck, Marcelo M. (Elsevier, 2024)   Artículo / Artikulua
      This work presents the fabrication of U-shaped plastic optical fiber (POF) sensors for hydrogen sulfide (H2S) detection, coated with Fe3O4 nanoparticles synthetized using the Pulsed Laser Ablation in Liquid (PLAL) technique. ...
    • Aggregator to electric vehicle LoRaWAN based communication analysis in vehicle-to-grid systems in smart cities 

      Klaina, Hicham Upna; Picallo Guembe, Imanol Upna Orcid; López Iturri, Peio Upna Orcid; Astrain Escola, José Javier Upna Orcid; Azpilicueta Fernández de las Heras, Leyre Upna Orcid; Falcone Lanas, Francisco Javier Upna Orcid (IEEE, 2020)   Artículo / Artikulua  OpenAccess
      Recently, there has been growing attention to the power grid management due to the increasing concerns on global warming. With the advancement in electric vehicles (EV) industry and the evolution in batteries, EVs become ...
    • All-fiber ellipsometer for nanoscale dielectric coatings 

      Imas González, José Javier Upna Orcid; Matías Maestro, Ignacio Upna Orcid; Del Villar, Ignacio Upna Orcid; Ozcariz Celaya, Aritz Upna Orcid; Ruiz Zamarreño, Carlos Upna Orcid; Albert, Jacques (Chinese Academy of Sciences, 2023)   Artículo / Artikulua  OpenAccess
      Multiple mode resonance shifts in tilted fiber Bragg gratings (TFBGs) are used to simultaneously measure the thickness and the refractive index of TiO2 thin films formed by Atomic Layer Deposition (ALD) on optical fibers. ...
    • Aluminum doped zinc oxide (AZO) coated optical fiber LMR refractometers. An experimental demonstration 

      Ozcariz Celaya, Aritz Upna Orcid; Piña-Azamar, Dafne A.; Ruiz Zamarreño, Carlos Upna Orcid; Domínguez Cruz, René; Arregui San Martín, Francisco Javier Upna Orcid (Elsevier, 2019)   Artículo / Artikulua  OpenAccess
      This work presents the experimental demonstration of lossy mode resonance generation by means of aluminum doped zinc oxide thin-films. The use of such material may allow to optimize the performance of LMR-based sensors, ...
    • Ammonia gas optical sensor based on lossy mode resonances 

      Armas, Dayron; Zubiate Orzanco, Pablo Upna Orcid; Ruiz Zamarreño, Carlos Upna Orcid; Matías Maestro, Ignacio Upna Orcid (IEEE, 2023)   Artículo / Artikulua  OpenAccess
      This letter presents the fabrication and characterization of an ammonia (NH 3) gas optical sensor based on lossy mode resonances (LMRs). A chromium (III) oxide (Cr 2 O 3) thin film deposited onto a planar waveguide was ...
    • Analysis and modelling of calendar ageing in second-life lithium-ion batteries from electric vehicles 

      Braco Sola, Elisa Upna; San Martín Biurrun, Idoia Upna Orcid; Sanchis Gúrpide, Pablo Upna Orcid; Ursúa Rubio, Alfredo Upna Orcid (IEEE, 2022)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      The reuse of Li-ion batteries from electric vehicles is a promising alternative to recycling nowadays. However, the technical and economic viability of these second-life (SL) batteries is not yet clear. Degradation ...
    • Analysis of gyrobianisotropic media effect on the input impedance, field distribution and mutual coupling of a printed dipole antenna 

      Bouknia, Mohamed Lamine; Zebiri, Chemseddine; Sayad, Djamel; Elfergani, Issa; Matin, Mohammad; Alibakhshikenari, Mohammad; Alharbi, Abdullah G.; Hu, Yim Fun; Abd-Alhameed, Raed; Rodriguez, Jonathan; Falcone Lanas, Francisco Javier Upna Orcid; Limiti, Ernesto (Springer Nature, 2022)   Artículo / Artikulua  OpenAccess
      In this paper, we present an analytical study for the investigation of the effects of the magnetoelectric elements of a reciprocal and nonreciprocal bianisotropic grounded substrate on the input impedance, resonant length ...

      El Repositorio ha recibido la ayuda de la Fundación Española para la Ciencia y la Tecnología para la realización de actividades en el ámbito del fomento de la investigación científica de excelencia, en la Línea 2. Repositorios institucionales (convocatoria 2020-2021).
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