Now showing items 121-140 of 160

    • Paraxiality considerations of higher order gaussian modes 

      Río Bocio, Carlos del Upna; Gonzalo García, Ramón Upna; Sorolla Ayza, Mario Upna (1996)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      Frequently, gaussian modes are used as free space wave equation solutions. This is not true since they are obtained assuming certain paraxial character in them. In this paper, we present an original study of the condition ...
    • Phase-shift based BOTDA measurements tolerant to non-local effects 

      Urricelqui Polvorinos, Javier Upna; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (SPIE, 2013)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      We demonstrate a BOTDA sensor based on the use of the Brillouin phase shift that performs measurements tolerant to non local effects. This technique raises opportunities to increase the distance covered by these sensors ...
    • Phasorial DPP-BOTDA sensor tolerant to non-local effects 

      Urricelqui Polvorinos, Javier Upna; Mariñelarena Ollacarizqueta, Jon Upna; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (SPIE, 2014)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      We introduce a modification of the differential pulse width pair technique in a BOTDA sensor based on a phase modulated probe wave and RF demodulation. This provides a differential Brillouin phasorial signal with high ...
    • Planar DNG superstrate for dipole antenna gain enhancement 

      Sáenz Sáinz, Elena Upna; Gonzalo García, Ramón Upna; Ederra Urzainqui, Íñigo Upna; Ikonen, Pekka; Tretyakov, Sergei A.; Maagt, Peter de (2007)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper, a volumetric double-negative (DNG) superstrate based on grids of dipoles and wires for dipole antenna applications is proposed.
    • Polarization diversity for Brillouin distributed fiber sensors based on a double orthogonal pump 

      Urricelqui Polvorinos, Javier Upna; López Fernandino, Felipe; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (SPIE, 2014)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      We demonstrate a novel Brillouin optical time domain analysis sensor deploying a polarization diversity technique which eliminates the need for polarization scrambling, providing measurements that are largely immune to the ...
    • Polyaniline deposition on tilted fiber Bragg grating for pH sensing 

      López Aldaba, Aitor Upna; González Vila, Á.; Debliquy, M.; López-Amo Sáinz, Manuel Upna; Caucheteur, C.; Lahem, D. (SPIE, 2017)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper, we present the results of a new pH sensor based on a polyaniline (PAni) coating on the surface of a tilted fiber Bragg grating. The pH-sensitive PAni was deposited by in situ chemical oxidative polymerization. ...
    • Radiation performances of a dipole array configuration inserted in a left-handed media 

      Sáenz Sáinz, Elena Upna; Gonzalo García, Ramón Upna; Ederra Urzainqui, Íñigo Upna; Maagt, Peter de (IEEE, 2005)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this work, the radiation improvements achieved when Left Handed Media (LHM) are combined with dipole antennas has been analysed. The behavior of two dipole antennas in array configuration when a Left Handed superstrate ...
    • Radiation performances of a multifrequency dipole antenna array with a left handed superstrate 

      Sáenz Sáinz, Elena Upna; Gonzalo García, Ramón Upna; Ederra Urzainqui, Íñigo Upna; Maagt, Peter de (2005)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper, the radiation performances of a multifrequency antenna array (MFAA) which consists of two dipoles (1 and 3) that are radiating at 9.57 GHz and other one (dipole 2) radiating at 11.98 GHz are presented. In ...
    • Random fiber lasers: application to fiber optic sensors networks 

      López-Amo Sáinz, Manuel Upna; Leandro González, Daniel Upna; Miguel Soto, Verónica de; Bravo Acha, Mikel Upna; Fernández Vallejo, Montserrat Upna; Pérez Herrera, Rosa Ana Upna (IEEE, 2017)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      Recently, random mirrors have been proposed as a method to create fiber laser cavities. This kind of cavity is based on cooperative Rayleigh scattering, which is generated along a fiber due to the material inhomogeneities ...
    • Redes de alimentación de agrupaciones basadas en CORPS 

      Betancourt Quiñones, Diego Upna; Río Bocio, Carlos del Upna (2006)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      A new beam-forming Network concept is introduced. This Network is based in the design principles of CORPS. The new proposed structure presents an improvement in design over the traditional beam-forming Network -BFN ...
    • Relative humidity multi-point optical sensors system based on Fast Fourier multiplexing technique 

      López Aldaba, Aitor Upna; López Torres, Diego Upna; Elosúa Aguado, César Upna; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; Arregui San Martín, Francisco Javier Upna; López-Amo Sáinz, Manuel Upna (SPIE, 2017)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper, a new multipoint optical fiber system for relative humidity measurements based on Sn02-FP (Fabry-Pérot) sensing heads and an optical interrogator as single active device is presented and characterized. The ...
    • Research on metamaterials for antenna applications 

      Gonzalo García, Ramón Upna; Ederra Urzainqui, Íñigo Upna; Iriarte Galarregui, Juan Carlos Upna; Martínez Pascual, Beatriz Upna; Sáenz Sáinz, Elena Upna; Cantora Álvarez, Pablo; Maagt, Peter de (2005)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      During the last 20 years a lot of attention has been paid to apply Electromagnetic Band Gap (EBG) technology in different frequency ranges, from microwaves to optics. EBG technology is based on the use of periodic structures ...
    • Resolution capabilities of future THz cameras 

      Lizarraga Cubillos, Juan Camilo Upna; Río Bocio, Carlos del Upna (2010)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      THz technology for developing imaging systems has recently aroused great interest, mainly due to the large number of applications in which these frequencies can be used: security, vision in hard environments, etc. In this ...
    • Respuesta EBG en microondas: ¿efecto Bragg o simplemente resonadores? 

      Ibáñez Loinaz, Asier; Río Bocio, Carlos del Upna (2004)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      A rigorous consideration of the EBG structures filtering effect at the microwave frequency range will be performed in this paper. We will show that in that frequency range, the periodic structure filtering (or Bragg ...
    • Resultados experimentales de la mejora de potencia radiada por un dipolo mediante un superstrato left-handed 

      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 a comparison between the measured radiation performances of a single dipole and a dipole with a left handed superstrate based on a finite periodic repetition of a unit cell is presented. First of all the ...
    • SCATTMAT: a mode matching and generalized scattering matrix code for personal computers in a windows environment 

      Liberal, Antonio; Río Bocio, Carlos del Upna; Gonzalo García, Ramón Upna; Sorolla Ayza, Mario Upna (1997)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper, a computer aided design tool is presented to simulate symmetrical radially deformed circular waveguide microwave components. This tool works with the well-known “Mode Matching and Scattering Matrix” ...
    • SCATTMAT: herramienta C.A.D. para el análisis de componentes en guía de onda circular con variaciones simétricas del radio 

      Liberal, Antonio; Lahera, Miguel; Río Bocio, Carlos del Upna; Gonzalo García, Ramón Upna; Sorolla Ayza, Mario Upna (1996)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper, a C.A.D. tool to simulate simmetrical radial deformation microwave devices, using the modal analysis and scattering matrix techniques is presented. The code has been developed in C++ language, working with ...
    • Sculpting metals for anomalous transmission phenomena, complex waves and negative refractive metamaterials: underlying physics and applications 

      Navarro Cía, Miguel Upna (2011)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this talk, the potential of controlling the electromagnetic propagation by periodically-textured surfaces is reviewed. It is shown that backward-wave- and slow-wave-propagation, superluminal, effective negative ...
    • Sensing in coin discriminators 

      Carlosena García, Alfonso Upna; López Martín, Antonio Upna; Arizti, Fernando; Martínez de Guereñu, Ane; Pina Insausti, José L.; García Sayés, Miguel (IEEE, 2007)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      This paper describes the technologies used in coin discriminator devices, stressing the improvements and novel mechanisms introduced by the authors in the past few years as a result of the cooperation with one leading ...
    • Simplified Brillouin sensor for structural health monitoring applications based on passive optical filtering 

      Iribas Pardo, Haritz Upna; Urricelqui Polvorinos, Javier Upna; Mariñelarena Ollacarizqueta, Jon Upna; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (SPIE, 2015)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      We present a simplified configuration for distributed Brillouin optical time domain analysis sensors. The technique is based on passive optical filtering of the spectral components generated in an RF-pulse-modulated optical ...