Now showing items 544-563 of 572

    • Ubiquitous connected train based on train-to-ground and intra-wagon communications capable of providing on trip customized digital services for passengers 

      Salaberria, Itziar; Perallos Ruiz, Asier; Azpilicueta Fernández de las Heras, Leyre Upna; Falcone Lanas, Francisco Javier Upna; Carballedo, Roberto; Angulo Martínez, Ignacio; Elejoste Larrucea, Pilar; Bahillo, Alfonso; Astrain Escola, José Javier Upna; Villadangos Alonso, Jesús Upna (MDPI, 2014)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      During the last years, the application of different wireless technologies has been explored in order to enable Internet connectivity from vehicles. In addition, the widespread adoption of smartphones by citizens represents ...
    • Ultra-compact planoconcave zoned metallic lens based on the fishnet metamaterial 

      Pacheco-Peña, Víctor Upna; Orazbayev, Bakhtiyar Upna; Torres Landívar, Víctor Upna; Beruete Díaz, Miguel Upna; Navarro Cía, Miguel Upna (AIP Publishing, 2013)   Artículo / Artikulua  OpenAccess
      A 1.5λ0 -thick planoconcave zoned lens based on the fishnet metamaterial is demonstrated experimentally at millimeter wavelengths. The zoning technique applied allows a volume reduction of 60% compared to a full fishnet ...
    • Ultra-long (290 km) remote interrogation sensor network based on a random distributed feedback fiber laser 

      Miguel Soto, Verónica de Upna; Leandro González, Daniel Upna; López-Amo Sáinz, Manuel Upna (Optical Society of America, 2018)   Artículo / Artikulua  OpenAccess
      In this work, an interferometric sensor has been interrogated 290 km away from the monitoring station, reaching the longest distance in fiber optic sensing up to date. This has been attained by employing a double-pumped ...
    • Ultra-wide band corrugated gaussian profiled horn antenna design 

      Teniente Vallinas, Jorge Upna; Gonzalo García, Ramón Upna; Río Bocio, Carlos del Upna (IEEE, 2001)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      A corrugated horn antenna design with more than 40% bandwidth is proposed in this paper. The measured radiated field patterns have a good agreement with the simulated ones. This antenna can be used in applications that ...
    • Ultra-wide band corrugated profiled horn antenna design 

      Teniente Vallinas, Jorge Upna; Gonzalo García, Ramón Upna; Río Bocio, Carlos del Upna (IEEE, 2002)   Artículo / Artikulua  OpenAccess
      Nowadays, an increasing number of applications need stable radiation patterns with low sidelobes and low crosspolar levels in a very wide bandwidth. Gaussian Profiled Horn Antennas (GPHA’s) have demonstrated its feasibility ...
    • Ultra-wideband metamaterial filter based on electroinductive-wave coupling between microstrips 

      Navarro Cía, Miguel Upna; Carrasco, J.M.; Beruete Díaz, Miguel Upna; Falcone Lanas, Francisco Javier Upna (EMW Publishing, 2009)   Artículo / Artikulua  OpenAccess
      In this work, we analyse the frequency response of microstrip lines coupled by complementary split ring resonators (CSRRs) etched on the ground plane supporting electroinductive waves (EIWs). The single-particle ...
    • Ultrafast electrooptic dual-comb interferometry 

      Durán, Vicente; Tainta Ausejo, Santiago Upna; Torres Company, Víctor (Optical Society of America, 2015)   Artículo / Artikulua  OpenAccess
      Dual-comb interferometry is a particularly compelling technique that relies on the phase coherence of two laser frequency combs for measuring broadband complex spectra. This method is rapidly advancing the field of optical ...
    • Ultrahigh-sensitivity sensors based on thin-film coated long period gratings with reduced diameter, in transition mode and near the dispersion turning point 

      Del Villar, Ignacio Upna (Optical Society of America, 2015)   Artículo / Artikulua  OpenAccess
      The mode transition and the dispersion turning point have been explored for optimization of thin-film coated long period fiber gratings during the last years. In this work and additional parameter, the cladding diameter, ...
    • Unified analysis of glottal source spectrum 

      Arroabarren Alemán, Ixone Upna; Zivanovic, Miroslav Upna; Carlosena García, Alfonso Upna (ISCA, 2003)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      The spectral study of the glottal excitation has traditionally been based on a single time-domain mathematical model of the signal, and the spectral dependence on its time domain parameters. Opposite to this approach, ...
    • Upper bounds on scattering processes and metamaterial-inspired structures that reach them 

      Ederra Urzainqui, Íñigo Upna; Liberal Olleta, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (IEEE, 2014)   Artículo / Artikulua  OpenAccess
      The physical limitations on time-harmonic scattering processes are investigated on the basis of the optical theorem. Previously derived least upper bounds on the total scattering and absorption cross-sections are obtained ...
    • Using CORPS-BFN to feed multibeam antenna systems 

      Betancourt Quiñones, Diego Upna; Río Bocio, Carlos del Upna (2007)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper, a simple example of application of the CORPS-BFN concept has been presented. A multibeam antenna system is seen as a small part of the human eye, and therefore, improving the similarity of the whole system ...
    • Utilizando CORPS-BFN para alimentar sistemas de antenas de múltiples haces 

      Betancourt Quiñones, Diego Upna; Río Bocio, Carlos del Upna (2007)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      This paper present an application of the Coherently Radiating Periodic Structures - CORPS on the design of a Beam Forming Network -BFN. The Named CORPS-BFN is a novel feeding network with special behaviour characteristics ...
    • Vertically coupled microring resonators using one epitaxial growth step and single-side lithography 

      García López, Óscar; Thourhout, Dries Van; Lasaosa Medarde, Daniel Upna; López-Amo Sáinz, Manuel Upna; Baets, Roel; Galarza Galarza, Marko Upna (Optical Society of America, 2015)   Artículo / Artikulua  OpenAccess
      A new concept for the fabrication of integrated microring resonators, requiring only one single epitaxial growth and two single-side lithographic steps, is proposed in what is the simplest fabrication scheme for vertical ...
    • Very short and efficient feeder design from monomode waveguide 

      Gonzalo García, Ramón Upna; Teniente Vallinas, Jorge Upna; Río Bocio, Carlos del Upna (IEEE, 1997)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper, we present an original and short corrugated horn antenna profile to obtain the HE11 corrugated circular waveguide mode exciting with a pure TE11 monomode smooth circular waveguide mode. We will obtain ...
    • Vibration detection using optical fiber sensors 

      Rodríguez García, Yoany; Corres Sanz, Jesús María Upna; Goicoechea Fernández, Javier Upna (Hindawi, 2010)   Artículo / Artikulua  OpenAccess
      Condition monitoring of heavy electromechanical equipment is commonly accomplished in the industry using vibration analysis. Several techniques, mainly based on capacitive and piezoelectric accelerometers, have been applied ...
    • Vibrato in singing voice: the link between source-filter and sinusoidal models 

      Carlosena García, Alfonso Upna; Arroabarren Alemán, Ixone Upna (Springer Open, 2004)   Artículo / Artikulua  OpenAccess
      The application of inverse filtering techniques for high-quality singing voice analysis/synthesis is discussed. In the context of source-filter models, inverse filtering provides a noninvasive method to extract the voice ...
    • Volatile organic compound optical fiber sensors: a review 

      Elosúa Aguado, César Upna; Matías Maestro, Ignacio Upna; Bariáin Aisa, Cándido Upna; Arregui San Martín, Francisco Javier Upna (MDPI, 2006)   Artículo / Artikulua  OpenAccess
      Volatile organic compound (VOC) detection is a topic of growing interest with applications in diverse fields, ranging from environmental uses to the food or chemical industries. Optical fiber VOC sensors offering new and ...
    • Wavelength and phase detection based SMS fiber sensors optimized with etching and nanodeposition 

      Cardona-Maya, Yamile; Del Villar, Ignacio Upna; Socorro Leránoz, Abián Bentor Upna; Corres Sanz, Jesús María Upna; Matías Maestro, Ignacio Upna; Botero-Cadavid, Juan F. (IEEE, 2016)   Artículo / Artikulua  OpenAccess
      The development of an optical fiber refractometer by hydrogen fluoride etching and sputtering deposition of a thin-film of indium tin oxide on a single-mode-multimode-single-mode fiber structure has been analyzed with ...
    • WDM bi-directional transmission over 35 km amplified fiber-optic bus network using Raman amplification for optical sensors 

      Díaz Lucas, Silvia Upna; Lasheras, Gorka; López-Amo Sáinz, Manuel Upna (Optical Society of America, 2005)   Artículo / Artikulua  OpenAccess
      We demonstrate a novel distributed fiber Raman amplified bus topology used for WDM transmission over 35 km of single-mode fiber by use of a multiwavelength Raman pump laser and eight Fiber Bragg gratings (FBGs). This ...
    • Wide angle terahertz sensing with a cross-dipole frequency selective surface 

      Rodríguez Ulibarri, Pablo Upna; Kuznetsov, Sergei A.; Beruete Díaz, Miguel Upna (AIP Publishing, 2016)   Artículo / Artikulua  OpenAccess
      In this work, a terahertz sensor based on a cross dipole frequency selective surface is analyzed and experimentally tested. The sensing structure is optimized for operation at the fundamental band- stop resonance near ...