• ±0.25 V Class-AB CMOS capacitance multiplier and precision rectifiers 

      Pourashraf, Shirin; Ramírez-Angulo, Jaime; Hinojo Montero, José María; González Carvajal, Ramón; López Martín, Antonio Upna Orcid (IEEE, 2019)   Artículo / Artikulua  OpenAccess
      Reduction of minimum supply requirements is a crucial aspect to decrease the power consumption in VLSI systems. A high performance capacitance multiplier able to operate with supplies as low as ±0.25 V is presented. It is ...
    • ±0.3v bulk-driven fully differential buffer with high figures of merit 

      Gangineni, Manaswini; Ramírez-Angulo, Jaime; Vázquez-Leal, Héctor; Huerta-Chua, Jesús; López Martín, Antonio Upna Orcid; González Carvajal, Ramón (MDPI, 2022)   Artículo / Artikulua  OpenAccess
      A high performance bulk-driven rail-to-rail fully differential buffer operating from ±0.3V supplies in 180 nm CMOS technology is reported. It has a differential–difference input stage and common mode feedback circuits ...
    • 0.6-V 1.65-uW second-order Gm-C bandpass filter for multi-frequency bioimpedance analysis based on a bootstrapped bulk-driven voltage buffer 

      Carrillo, Juan M.; Cruz Blas, Carlos Aristóteles de la Upna Orcid (MDPI, 2022)   Artículo / Artikulua  OpenAccess
      A bootstrapping technique used to increase the intrinsic voltage gain of a bulk-driven MOS transistor is described in this paper. The proposed circuit incorporates a capacitor and a cutoff transistor to be connected to ...
    • A 3-D indoor analysis of path loss modeling using kriging techniques 

      Diago Mosquera, Melissa; Aragón Zavala, Alejandro; Azpilicueta Fernández de las Heras, Leyre Upna Orcid; Shubair, Raed M.; Falcone Lanas, Francisco Javier Upna Orcid (IEEE, 2022)   Artículo / Artikulua  OpenAccess
      This study proposes a novel measurement-based method to predict and model three-dimensional (3-D) path loss in indoor scenarios, which first regresses 28 GHz measurements via median path loss modeling and then includes ...
    • 3-D printed horn antennas and components performance for space and telecommunications 

      Teniente Vallinas, Jorge; Iriarte Galarregui, Juan Carlos; Caballero Nagore, Rubén; Valcázar Berdofe, Daniel; Goñi, Mikel; Martínez, Aitor (IEEE, 2018)   Artículo / Artikulua  OpenAccess
      In this work, a study of the performance of several antennas and components, manufactured using an accurate stereolithography 3D printer and resin for maximum accuracy and detail, is carried out. Electroless plating of ...
    • 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 ...
    • 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. ...

      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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