Now showing items 109-128 of 149

    • On the determination of the phase center of gaussian horn antennas 

      Río Bocio, Carlos del Upna; Teniente Vallinas, Jorge Upna; Gonzalo García, Ramón Upna; Sorolla Ayza, Mario Upna (1998)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      Gaussian horn antenna designs have experimentally demonstrated excellent performance to produce a very pure Gaussian beam mode with extremely low sidelobes and crosspolarization levels. These results make very attractive ...
    • Optimal horn antenna design to excite high purity gaussian beam using overmoded waveguides 

      Gonzalo García, Ramón Upna; Río Bocio, Carlos del Upna; Teniente Vallinas, Jorge Upna; Sorolla Ayza, Mario Upna (1996)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper, we present an original and optimal multimode horn antenna design to excite the fundamental Gaussian beam from an overmoded waveguide. In particular, we focus the study in overmoded circular corrugated ...
    • Optimized antenna system for low power testing of the quasioptical transmission line at TJ-II experiment 

      Sorolla Ayza, Mario Upna; Río Bocio, Carlos del Upna; Gonzalo García, Ramón Upna; Sánchez Corpas, Alberto Upna; Martín, Romualdo; Fernández, Ángela; Cepero, José R.; Likin, Konstantin M.; Sarksyan, Karen (1996)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper we present a high performance antenna system to carry out low power testing of the main parameters of the quasioptical transmission line system for Electron Cyclotron Resonance Heating (ECRH) at TJ-II ...
    • Optimized feedhorn designs for compact antenna test range at Limoges University 

      Teniente Vallinas, Jorge Upna; Arnaud, Eric; Gonzalo García, Ramón Upna; Río Bocio, Carlos del Upna (IEEE, 2006)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper, high technology optimized feedhorn designs are presented. These feedhorns have been designed to improve the quite zone size and behaviour at the Compact Antenna Test Range (CATR) of the Antenna Research ...
    • Optimum horn antennas for high order mode beam waveguides 

      Río Bocio, Carlos del Upna; Gonzalo García, Ramón Upna; Sorolla Ayza, Mario Upna; Thumm, Manfred (1995)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      Higher order free space modes can be considered as serious candidates for power millimeter wave transmission in advanced material processing by using medium power CW gyrotrons. These modes can be propagated in a beam ...
    • Overcoming non-local effects and Brillouin threshold limitations in Brillouin distributed sensors 

      Urricelqui Polvorinos, Javier Upna; Ruiz Lombera, Rubén; Sagüés García, Mikel Upna; Mirapeix, Jesús; López Higuera, José Miguel; Loayssa Lara, Alayn Upna (SPIE, 2015)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      We demonstrate, for the first time to our knowledge, a Brillouin optical time domain analysis sensor that is able to operate with a probe power larger than the Brillouin threshold of the deployed sensing fiber and that ...
    • Parametric study of pin surface used to suppress undesired modes in a packaged W-band microstrip receiver 

      Rebollo Mugueta, Ainara Upna; Maestrojuán Biurrun, Itziar Upna; Larumbe Gonzalo, Belén Upna; Gonzalo García, Ramón Upna; Ederra Urzainqui, Íñigo Upna (IEEE, 2013)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      A pin surface structure has been used in order to suppress undesired modes in a packaged W-band RF front-end receiver. A parametric analysis has been carried out in order to determine the optimum dimensions. Resonances ...
    • 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 ...
    • 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 ...
    • 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 ...
    • 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” ...