Now showing items 407-426 of 572

    • Parameter-independent control for battery chargers based on virtual impedance emulation 

      Urtasun Erburu, Andoni Upna; Berrueta Irigoyen, Alberto Upna; Sanchis Gúrpide, Pablo Upna; Marroyo Palomo, Luis Upna (IEEE, 2018)   Artículo / Artikulua  OpenAccess
      An effective battery voltage regulation is fundamental to extend battery lifetime and to avoid overvoltage. However, the design of this regulation is complicated due to the wide battery impedance range, which, when dealing ...
    • 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 ...
    • Passive microwave component design using inverse scattering: theory and applications 

      Arnedo Gil, Israel Upna; Arregui Padilla, Iván Upna; Chudzik, Magdalena Upna; Teberio Berdún, Fernando Upna; Lujambio Genua, Aintzane Upna; Benito Pertusa, David Upna; Lopetegui Beregaña, José María Upna; Gómez Laso, Miguel Ángel Upna (Hindawi, 2013)   Artículo / Artikulua  OpenAccess
      We briefly review different synthesis techniques for the design of passive microwave components with arbitrary frequency response, developed by our group during the last decade. We provide the theoretical foundations based ...
    • Performance analysis of IEEE 802.15.4 compliant wireless devices for heterogeneous indoor home automation environments 

      Nazábal Urriza, Juan Antonio Upna; López Iturri, Peio Upna; Azpilicueta Fernández de las Heras, Leyre Upna; Falcone Lanas, Francisco Javier Upna; Fernández Valdivielso, Carlos Upna (Hindawi, 2012)   Artículo / Artikulua  OpenAccess
      The influence of topology as well as morphology of complex indoor scenarios in the deployment of wireless sensor networks and wireless systems applied to home and building automation systems is analyzed. The existence of ...
    • Performance analysis of ZigBee wireless networks for AAL through hybrid ray launching and collaborative filtering 

      López Iturri, Peio Upna; Casino, Fran; Aguirre Gallego, Erik Upna; Azpilicueta Fernández de las Heras, Leyre Upna; Falcone Lanas, Francisco Javier Upna; Solanas, Agusti (Hindawi, 2016)   Artículo / Artikulua  OpenAccess
      This paper presents a novel hybrid simulation method based on the combination of an in-house developed 3D ray launching algorithm and a collaborative filtering (CF) technique, which will be used to analyze the performance ...
    • Performance comparison and design guidelines for Type II and Type III PLLs 

      Ugarte Gil, Mikel Upna; Carlosena García, Alfonso Upna (Birkhauser, 2015)   Artículo / Artikulua  OpenAccess
      The advantages provided by Type III PLLs are poorly known, since these devices are very often considered unstable and difficult, or even impossible, to design. In this paper, a performance comparison between Type II and ...
    • Phase reversal technique applied to fishnet metalenses 

      Pacheco-Peña, Víctor Upna; Minin, Igor V.; Minin, Oleg V.; Beruete Díaz, Miguel Upna (Hindawi, 2018)   Artículo / Artikulua  OpenAccess
      In this work, the fishnet metamaterial is applied to several converging metalenses by combining the zoning, reference phase, and phase reversal techniques. First, the zoning and reference phase techniques are implemented ...
    • 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 differential pulse-width pair technique for long-range Brillouin optical time-domain analysis sensors 

      Urricelqui Polvorinos, Javier Upna; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (Optical Society of America, 2014)   Artículo / Artikulua  OpenAccess
      We introduce a novel phasorial differential pulse width pair (PDPP) method for Brillouin optical time domain analysis (BOTDA) sensors that combines spatial resolution enhancement with increased tolerance to non local ...
    • 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 ...
    • Photonic crystal fiber temperature sensor based on quantum dot nanocoatings 

      Larrión Zabaleta, Beatriz Upna; Hernáez Sáenz de Zaitigui, Miguel Upna; Arregui San Martín, Francisco Javier Upna; Goicoechea Fernández, Javier Upna; Bravo Larrea, Javier Upna; Matías Maestro, Ignacio Upna (Hindawi / Wiley, 2009)   Artículo / Artikulua  OpenAccess
      Quantum dot nanocoatings have been deposited by means of the Layer-by-Layer technique on the inner holes of Photonic Crystal Fibers (PCFs) for the fabrication of temperature sensors. The optical properties of these sensors ...
    • Photonic crystal fibers for sensing applications 

      Rodrigues Pinto, Ana Margarida Upna; López-Amo Sáinz, Manuel Upna (Hindawi Publishing Corporation, 2012)   Artículo / Artikulua  OpenAccess
      Photonic crystal fibers are a kind of fiber optics that present a diversity of new and improved features beyond what conventional optical fibers can offer. Due to their unique geometric structure, photonic crystal fibers present ...
    • 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.
    • Planar holographic metasurfaces for terahertz focusing 

      Kuznetsov, Sergei A.; Astafev, Mikhail A.; Beruete Díaz, Miguel Upna; Navarro Cía, Miguel Upna (Springer Nature, 2015)   Artículo / Artikulua  OpenAccess
      Scientists and laymen alike have always been fascinated by the ability of lenses and mirrors to control light. Now, with the advent of metamaterials and their two-dimensional counterpart metasurfaces, such components can ...
    • Planar magnetoinductive wave transducers: theory and applications 

      Freire, M. J.; Marqués, R.; Medina, Francisco; Gómez Laso, Miguel Ángel Upna; Martín, F. (AIP Publishing, 2004)   Artículo / Artikulua  OpenAccess
      Transduction of magnetoinductive waves (MIWs) in planar technology is demonstrated. A transducer consisting of a one-dimensional periodic array of metallic split squared ring resonators (SSRR), placed between a pair of ...
    • Planoconcave lens by negative refraction of stacked subwavelength hole arrays 

      Beruete Díaz, Miguel Upna; Navarro Cía, Miguel Upna; Sorolla Ayza, Mario Upna; Campillo, Igor (Optical Society of America, 2008)   Artículo / Artikulua  OpenAccess
      This work presents the design of a planoconcave parabolic negative index metamaterial lens operating at millimeter wavelengths fabricated by using stacked subwavelength hole arrays. A staircase approximation to the ideal ...
    • Plasmonics and metamaterials at terahertz frequencies 

      Torres Landívar, Víctor Upna (2014)   Tesis doctoral / Doktoretza tesia  OpenAccess
      The research presented in this manuscript falls under the framework of metamaterials and plasmonics. It is mainly focused on applications at terahertz (THz) frequencies, a spectral band located between microwaves and ...
    • 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 ...
    • Polarization diversity scheme for BOTDA sensors based on a double orthogonal pump interaction 

      Urricelqui Polvorinos, Javier Upna; López Fernandino, Felipe; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (IEEE, 2015)   Artículo / Artikulua  OpenAccess
      We introduce a Brillouin optical time domain analysis (BOTDA) sensor deploying a novel polarization diversity technique based on the use of two orthogonal pump pulses which simultaneously interact with a phase modulated ...