Now showing items 1-20 of 267

    • Hybrid Raman‑erbium random fiber laser with a half open cavity assisted by artificially controlled backscattering fiber refectors 

      Pérez Herrera, Rosa Ana Upna Orcid; Roldán Varona, Pablo; Sañudo-Lasagabaster Ibáñez, Silvia; Rodríguez Cobo, L.; López Higuera, José Miguel; López-Amo Sáinz, Manuel Upna Orcid (Springer Nature, 2021)   Artículo / Artikulua  OpenAccess
      A hybrid Raman-erbium random fber laser with a half-open cavity assisted by chirped artifcially controlled backscattering fber refectors is presented. A combination of a 2.4 km-long dispersion compensating fber with two ...
    • Energy-efficient amplifiers based on quasi-floating gate techniques 

      López Martín, Antonio Upna; Garde Luque, María Pilar Upna; Algueta-Miguel, Jose M. Upna; Beloso Legarra, Javier; González Carvajal, Ramón; Ramírez-Angulo, Jaime (MDPI, 2021)   Artículo / Artikulua  OpenAccess
      Energy efficiency is a key requirement in the design of amplifiers for modern wireless applica-tions. The use of quasi-floating gate (QFG) transistors is a very convenient approach to achieve such energy efficiency. We ...
    • Silicon integrated subharmonic mixer on a photonic-crystal platform 

      Torres García, Alicia E. Upna Orcid; Pérez Escudero, José Manuel Upna Orcid; Teniente Vallinas, Jorge Upna Orcid; Gonzalo García, Ramón Upna Orcid; Ederra Urzainqui, Íñigo Upna Orcid (IEEE, 2021)   Artículo / Artikulua
      This paper presents a planar silicon integrated subharmonic mixer on top of a photonic-crystal platform. The local oscillator (LO) power is injected through a 2D photoniccrystal (PC) slab to a resonant cavity that effectively ...
    • Super-gain-boosted AB-AB fully differential Miller op-amp with 156dB open-loop gain and 174MV/V MHZ pF/uW figure of merit in 130nm CMOS technology 

      Paul, Anindita; Ramírez-Angulo, Jaime; Díaz Sánchez, Alejandro; López Martín, Antonio Upna; González Carvajal, Ramón; Li, Frank X. (IEEE, 2021)   Artículo / Artikulua  OpenAccess
      A fully differential Miller op-amp with a composite input stage using resistive local common-mode feedback and regulated cascode transistors is presented here. High gain pseudo-differential auxiliary amplifiers are used ...
    • Propagation models in vehicular communications 

      Rodríguez Corbo, Fidel Alejandro; Azpilicueta Fernández de las Heras, Leyre; Celaya Echarri, Mikel; Vázquez Alejos, Ana; Falcone Lanas, Francisco Javier (IEEE, 2021)   Artículo / Artikulua  OpenAccess
      In the advent of becoming reality, the era of autonomous vehicles is closer than ever, and with it, the need for faster and reliable wireless connections. The propagation channel determines the performance limits of wireless ...
    • Liquid level sensor based on dynamic Fabry–Perot interferometers in processed capillary fiber 

      Roldán Varona, Pablo; Pérez Herrera, Rosa Ana Upna Orcid; Rodríguez Cobo, L.; Reyes González, Luis; López-Amo Sáinz, Manuel Upna Orcid (Springer Nature, 2021)   Artículo / Artikulua  OpenAccess
      In this work, a novel optical fiber sensor capable of measuring both the liquid level and its refractive index is designed, manufactured and demonstrated through simulations and experimentally. For this, a silica capillary ...
    • Design and experimental validation of an augmented reality system with wireless integration for context aware enhanced show experience in auditoriums 

      Picallo Guembe, Imanol; Vidal Balea, A.; Blanco Novoa, Óscar; López Iturri, Peio; Fraga Lamas, Paula; Azpilicueta Fernández de las Heras, Leyre; Falcone Lanas, Francisco Javier; Fernández Caramés, Tiago M.; Klaina, Hicham (IEEE, 2021)   Artículo / Artikulua  OpenAccess
      The development of multiple cultural and social related activities, such as shows related with the performing arts, conferences or presentations rely on facilities such as auditoriums, theatres and conference sites, which ...
    • Study on on-chip antenna design based on metamaterial-inspired and substrate-integrated waveguide properties for millimetre-wave and THz integrated-circuit applications 

      Alibakhshikenari, Mohammad; Virdee, Bal S.; Althuwayb, Ayman Abdulhadi; Aïssa, Sonia; See, Chan H.; Abd-Alhameed, Raed; Falcone Lanas, Francisco Javier Upna Orcid; Limiti, Ernesto (Springer, 2021)   Artículo / Artikulua  OpenAccess
      This paper presents the results of a study on improving the performance parameters such as the impedance bandwidth, radiation gain and efficiency, as well as suppressing substrate loss of an innovative antenna for on-chip ...
    • Urban e-grocery distribution design in Pamplona (Spain) applying an agent-based simulation model with horizontal cooperation scenarios 

      Serrano Hernández, Adrián; Torre, Rocío de la; Cadarso, Luis; Faulín Fajardo, Javier (MDPI, 2021)   Artículo / Artikulua  OpenAccess
      E-commerce has boosted in the last decades because of the achievements of the information and telecommunications technology along with the changes in the society life-style. More recently, the groceries online purchase (or ...
    • On the reduction of authoritative DNS cache timeouts: detection and implications for user privacy 

      Hernández Quintanilla, Tomás; Magaña Lizarrondo, Eduardo Upna Orcid; Morató Osés, Daniel Upna Orcid; Izal Azcárate, Mikel Upna Orcid (Elsevier, 2021)   Artículo / Artikulua  OpenAccess
      The domain name system (DNS) is an Internet network service that is used by hosts to resolve IP addresses from symbolic names. This basic service has been attacked and abused many times, as it is one of the oldest and most ...
    • Metageometries for polycyclic aromatic hydrocarbons detection at THz range in food systems 

      Jáuregui López, Irati Upna Orcid; Insausti Barrenetxea, Kizkitza Upna Orcid; Beriain Apesteguía, María José Upna Orcid; Beruete Díaz, Miguel Upna Orcid (IEEE, 2021)   Artículo / Artikulua
      Polycyclic aromatic hydrocarbons, when present in food systems, have been shown to have a detrimental effect on human health, producing carcinogenic elements. So, the implementation of processes for their detection and ...
    • Ultrathin and high-efficiency Pancharatnam-Berry phase metalens for millimeter waves 

      Moreno-Peñarrubia, Alexia; Teniente Vallinas, Jorge; Kuznetsov, Sergei A.; Orazbayev, Bakhtiyar; Beruete Díaz, Miguel (AIP Publishing, 2021)   Artículo / Artikulua  OpenAccess
      Applying the Pancharatnam–Berry (PB) principle to half-wave plate (HWP) metasurfaces allows the manipulation of wavefronts along with the conversion of the handedness of circularly polarized incident waves by simply rotating ...
    • Multiparameter sensor based on a multiinterferometric serial configuration for temperature and strain measurements 

      Pérez Herrera, Rosa Ana Upna Orcid; Bravo Acha, Mikel Upna Orcid; Leandro González, Daniel Upna Orcid; Novais, Susana; Pradas Martínez, Javier; López-Amo Sáinz, Manuel Upna Orcid (IEEE, 2021)   Artículo / Artikulua
      In this work, a multi-parameter point sensor based on the combination of Fabry-Perot (FP) and the anti-resonant (AR) reflecting guidance in cascade configuration is proposed and experimentally demonstrated. This structure, ...
    • Bull’s-eye antenna with circular polarization at millimeter waves based on ridge gap waveguide technology 

      Pérez, Dayan Upna Orcid; Ederra Urzainqui, Íñigo Upna Orcid; Beruete Díaz, Miguel Upna Orcid (IEEE, 2021)   Artículo / Artikulua
      In this communication, a Bull’s-Eye (BE) antenna with circular polarization (CP) based on ridge gap waveguide (RGW) technology is numerically and experimentally demonstrated. The structure is excited from the bottom with ...
    • Silicon carbide as a material-based high-impedance surface for enhanced absorption within ultra-thin metallic films 

      Pérez Escudero, José Manuel Upna Orcid; Buldain, Iban; Beruete Díaz, Miguel Upna Orcid; Goicoechea Fernández, Javier Upna Orcid; Liberal Olleta, Íñigo Upna Orcid (Optical Society of America, 2020)   Artículo / Artikulua  OpenAccess
      The absorption of infrared radiation within ultra-thin metallic films is technologically relevant for different thermal engineering applications and optoelectronic devices, as well as for fundamental research on sub-nanometer ...
    • 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; 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 comprehensive survey on "Various decoupling mechanisms with focus on metamaterial and metasurface principles applicable to SAR and MIMO antenna systems" 

      Alibakhshikenari, Mohammad; Babaeian, Fatemeh; Virdee, Bal S.; Aïsa, Sonia; Azpilicueta Fernández de las Heras, Leyre Upna Orcid; See, Chan H.; Falcone Lanas, Francisco Javier Upna Orcid; Althuway, Ayman Abdulhadi; Huynen, Isabelle; Abd-Alhameed, Raed; Limiti, Ernesto (IEEE, 2020)   Artículo / Artikulua  OpenAccess
      Nowadays synthetic aperture radar (SAR) and multiple-input-multiple-output (MIMO) antenna systems with the capability to radiate waves in more than one pattern and polarization are playing a key role in modern telecommunication ...
    • Maximum expected ramp rates using cloud speed sensor measurements 

      Wang, Guang Chao; Kurtz, Ben; Bosch, Juan Luis; Parra Laita, Íñigo de la Upna Orcid; Kleissl, Jan (American Institute of Physics, 2020)   Artículo / Artikulua
      Large ramps and ramp rates in photovoltaic (PV) power output are of concern and sometimes even explicitly restricted by grid operators. Battery energy storage systems can smooth the power output and maintain ramp rates ...
    • Optical fiber vacuum sensor based on etched SMS structure and PDMS coating 

      Ascorbe Muruzabal, Joaquín Upna Orcid; Fuentes Lorenzo, Omar Upna; Arregui San Martín, Francisco Javier Upna Orcid; Matías Maestro, Ignacio Upna Orcid; Corres Sanz, Jesús María Upna Orcid (IEEE, 2020)   Artículo / Artikulua
      In this work, an optical fiber vacuum sensor based on a single-mode multimode single-mode (SMS) structure coated with polydimethylsiloxane (PDMS) is studied. The SMS structure generates an interferometric pattern based on ...
    • Similarity between interval-valued fuzzy sets taking into account the width of the intervals and admissible orders 

      Bustince Sola, Humberto Upna Orcid; Marco Detchart, Cedric Upna Orcid; Fernández Fernández, Francisco Javier Upna Orcid; Wagner, C.; Garibaldi, J. M. (Elsevier, 2020)   Artículo / Artikulua
      In this work we study a new class of similarity measures between interval-valued fuzzy sets. The novelty of our approach lays, firstly, on the fact that we develop all the notions with respect to total orders of intervals; ...