Now showing items 39-58 of 572

    • Band-pass filter-like antenna validation in an ultra-wideband in-car wireless channel 

      García Zuazola, Ignacio Julio; Azpilicueta Fernández de las Heras, Leyre Upna; Sharma, Ashwani; Landaluce, Hugo; Falcone Lanas, Francisco Javier Upna (Institution of Engineering and Technology (IET), 2015)   Artículo / Artikulua  OpenAccess
      Ultra-wideband (UWB) is a very attractive technology for innovative in-car wireless communications requiring high data rates. A designated antenna, which presents a reflection coefficient (S11) matched band comparable to ...
    • The beauty of anisotropy in extraordinary transmission fishnet metamaterials 

      Navarro Cía, Miguel Upna; Beruete Díaz, Miguel Upna; Sorolla Ayza, Mario Upna (2011)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this work, we explore both numerically and experimentally, the possibility to obtain positive and negative refraction regimes that depend on the wave polarization, exploiting the strong anisotropy of extraordinary ...
    • Blind spot mitigation in phased array antenna using metamaterials 

      Crépin, Thomas; Martel, Cédric; Gabard, Benjamin; Boust, Fabrice; Martinaud, Jean-Paul; Dousset, Thierry; Rodríguez Ulibarri, Pablo Upna; Beruete Díaz, Miguel Upna; Loecker, Claudius; Bertuch, Thomas; Marcotegui, José Antonio Upna; Maci, Stefano (IEEE, 2014)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this work, a metaradome based on a fakir’s bed of nails is designed and tested in order to suppress the blind directions of a 100-element antenna array. The antenna is a microstrip array designed to operate in X-band. ...
    • Boresight radiation of a dipole antenna with a uniform or non-uniform left handed superstrate 

      Sáenz Sáinz, Elena Upna; Gonzalo García, Ramón Upna; Ederra Urzainqui, Íñigo Upna; Maagt, Peter de (2006)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper measurements of the radiation performances of a dipole fed by a coaxial balun and a dipole with a left handed superstrate based on a finite periodic repetition of a unit cell are compared. Two types ...
    • BOTDA measurements tolerant to non-local effects by using a phase-modulated probe wave and RF demodulation 

      Urricelqui Polvorinos, Javier Upna; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (Optical Society of America, 2013)   Artículo / Artikulua  OpenAccess
      We demonstrate a Brillouin optical time domain analysis sensor based on a phase modulated probe wave and RF demodulation that provides measurements tolerant to frequency dependent variations of the pump pulse power induced ...
    • Brillouin distributed sensing assisted by Brillouin amplification of pump pulses 

      Urricelqui Polvorinos, Javier Upna; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (IEEE, 2014)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      We demonstrate, for the first time to our knowledge, the extension of the measurement range of Brillouin distributed sensors (BDS) by using a distributed Brillouin amplifier (DBA) to compensate the attenuation of the ...
    • Brillouin optical time-domain analysis sensor assisted by Brillouin distributed amplification of pump pulses 

      Urricelqui Polvorinos, Javier Upna; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (Optical Society of America, 2015)   Artículo / Artikulua  OpenAccess
      We demonstrate the extension of the measurement range of Brillouin optical time-domain analysis (BOTDA) sensors using a distributed Brillouin amplifier (DBA). The technique is based on injecting a DBA pump wave in the ...
    • Brillouin optical time-domain analysis sensor with amplification of pump pulses and tolerant to non-local effects 

      Mompó Roselló, Juan José Upna; Urricelqui Polvorinos, Javier Upna; Loayssa Lara, Alayn Upna (SPIE, 2016)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      We demonstrate a simple technique to provide conventional Brillouin optical time-domain analysis sensor with compensation for pump pulse attenuation and tolerance to non-local effects. The technique is based on operating ...
    • Brillouin optical time-domain analysis sensor with pump pulse amplification 

      Mompó Roselló, Juan José Upna; Urricelqui Polvorinos, Javier Upna; Loayssa Lara, Alayn Upna (Optical Society of America, 2016)   Artículo / Artikulua  OpenAccess
      We demonstrate a simple technique to provide conventional Brillouin optical time-domain analysis sensors with mitigation for pump pulse attenuation. The technique is based on operating the sensor in loss configuration so ...
    • Brillouin optical time-domain analyzer for extended sensing range using probe dithering and cyclic coding 

      Iribas Pardo, Haritz Upna; Loayssa Lara, Alayn Upna; Sauser, Florian; Llera, Miguel; Le Floch, Sébastien (SPIE, 2017)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      We present an enhanced performance Brillouin optical time-domain analysis sensor that uses dual probes waves with optical frequency modulation and cyclic coding. The frequency modulation serves to increase the probe power ...
    • Brilloun optical time domain analysis sensor assisted by a Brillouin distributed amplifier 

      Urricelqui Polvorinos, Javier Upna; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (SPIE, 2015)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      We demonstrate the extension of the measurement range of Brillouin optical time-domain analysis (BOTDA) sensors using a distributed Brillouin amplifier (DBA). The technique is based on injecting a DBA pump wave in the ...
    • Broadband frequency and angular response of a sinusoidal bull’s eye antenna 

      Beaskoetxea Gartzia, Unai Upna; Navarro Cía, Miguel Upna; Beruete Díaz, Miguel Upna (IOP Publishing, 2016)   Artículo / Artikulua  OpenAccess
      A thorough experimental study of the frequency and beaming angle response of a metallic leaky-wave bull’s eye antenna working at 77 GHz with a sinusoidally corrugated profile is presented. The beam scanning property of ...
    • Broadband radar cross-section reduction using AMC technology 

      Iriarte Galarregui, Juan Carlos Upna; Tellechea Pereda, Amagoia Upna; Martínez de Falcón, José Luis Upna; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Maagt, Peter de (IEEE, 2013)   Artículo / Artikulua  OpenAccess
      This paper presents the design, fabrication and characterization of a planar broadband chessboard structure to reduce the radar cross-section (RCS) of an object. The chessboard like configuration is formed by combining two ...
    • Broadband spoof plasmons and subwavelength electromagnetic energy confinement on ultrathin metafilms 

      Navarro Cía, Miguel Upna; Beruete Díaz, Miguel Upna; Agrafiotis, Spyros; Falcone Lanas, Francisco Javier Upna; Sorolla Ayza, Mario Upna; Maier, Stefan A. (Optical Society of America, 2009)   Artículo / Artikulua  OpenAccess
      A complementary split ring resonator (CSRR)-based metallic layer is proposed as a route to mimic surface plasmon polaritons. A numerical analysis of the textured surface is carried out and compared to previous prominent ...
    • Challenges in wireless system integration as enablers for indoor context aware environments 

      López Iturri, Peio Upna; Aguirre Gallego, Erik Upna; Azpilicueta Fernández de las Heras, Leyre Upna; Astrain Escola, José Javier Upna; Villadangos Alonso, Jesús Upna; Falcone Lanas, Francisco Javier Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      The advent of fully interactive environments within Smart Cities and Smart Regions requires the use of multiple wireless systems. In the case of user-device interaction, which finds multiple applications such as Ambient ...
    • Characterization of microring filters for differential group delay applications 

      Doménech, D.; Chamorro Posada, P.; Fraile Pelaez, F.J.; Erro Betrán, María José Upna; Tainta Ausejo, Santiago Upna; Muriel, M. A.; Baños, R.; Bolten, J.; Kleinjans, H. (IEEEOptical Society of America, 2017)   Artículo / Artikulua  OpenAccess
      The longitudinal offset technique permits to improve the accuracy of the coupling coefficients of integrated directional couplers and provides designs that can be easily implemented with current fabrication tolerances. ...
    • Characterization of near-ground radio propagation channel for wireless sensor network with application in smart agriculture 

      Klaina, Hicham; Alejos, Ana; Aghzout, Otman; Falcone Lanas, Francisco Javier Upna (MDPI, 2017)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this contribution, we present a narrowband radio channel model for a scenario wherein the radio link operates under near-ground conditions, occurring on a ZigBee wireless sensor networks applied to smart agriculture. ...
    • Characterization of radio propagation channel in urban vehicle to infrastructure environments to support WSNs 

      Granda, Fausto; Azpilicueta Fernández de las Heras, Leyre Upna; Vargas Rosales, César; López Iturri, Peio Upna; Aguirre Gallego, Erik Upna; Astrain Escola, José Javier Upna; Villadangos Alonso, Jesús Upna; Falcone Lanas, Francisco Javier Upna (MDPI, 2016)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      Vehicular ad hoc Networks (VANETs) enable vehicles to communicate with each other as well as with roadside units (RSUs). Although there is a significant research effort in radio channel modelling focused in vehicle to ...
    • Characterization of wireless channel impact on wireless sensor network performance in public transportation buses 

      Azpilicueta Fernández de las Heras, Leyre Upna; López Iturri, Peio Upna; Aguirre Gallego, Erik Upna; Astrain Escola, José Javier Upna; Villadangos Alonso, Jesús Upna; Zubiri Segura, Cristóbal; Falcone Lanas, Francisco Javier Upna (IEEE, 2015)   Artículo / Artikulua  OpenAccess
      Wireless communications systems are growing rapidly during the last two decades and they are gaining a significant role for multiple communication tasks within public transportation buses. In this work, the impact of ...
    • Characterization of wireless propagation in complex indoor environments 

      Azpilicueta Fernández de las Heras, Leyre Upna (2015)   Tesis doctoral / Doktoretza tesia  OpenAccess
      En este trabajo de investigación se ha propuesto un nuevo modelo de propagación determinista para analizar la propagación radioeléctrica en entornos complejos. En primer lugar, se ha realizado un profundo análisis de los ...