Now showing items 191-210 of 297

    • Optimization in nanocoated D-shaped optical fiber sensors 

      Del Villar, Ignacio Upna; Zubiate Orzanco, Pablo Upna; Ruiz Zamarreño, Carlos Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (Optical Society of America, 2017)   Artículo / Artikulua  OpenAccess
      Nanocoated D-shaped optical fibers have been proven as effective sensors. Here, we show that the full width at half minimum (FWHM) of lossy mode resonance can be reduced by optimizing the nanocoating width, thickness and ...
    • Optimization of a pin surface as a solution to suppress cavity modes in a packaged W-band microstrip receiver 

      Rebollo Mugueta, Ainara Upna; Gonzalo García, Ramón Upna; Ederra Urzainqui, Íñigo Upna (IEEE, 2014)   Artículo / Artikulua  OpenAccess
      A pin surface structure has been used in the upper metal plate of a packaged W-band RF front-end receiver in order to suppress the propagation of unwanted modes. A full parametric analysis of the periodic structure within ...
    • Optimization of sensitivity in long period fiber gratings with overlay deposition 

      Del Villar, Ignacio Upna; Matías Maestro, Ignacio Upna; Arregui San Martín, Francisco Javier Upna; Lalanne, Philippe (Optical Society of America, 2005)   Artículo / Artikulua  OpenAccess
      The deposition of an overlay of higher refractive index than the cladding in a Long Period Fiber Grating (LPFG) permits to improve the sensitivity to ambient refractive index changes in a great manner. When the overlay is ...
    • Optimization of sensors based on multimode interference in single-mode–multimode– single-mode structure 

      Del Villar, Ignacio Upna; Socorro Leránoz, Abián Bentor Upna; Corres Sanz, Jesús María Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (IEEE, 2013)   Artículo / Artikulua  OpenAccess
      By coating a single-mode–multimode–single-mode (SMS) structure with a complex refractive index thin-film the central wavelength of the transmission and attenuation bands of the optical spectrum can be shifted. By adequate ...
    • An optimized method based on digitalized Lissajous curve to determine lifetime of luminescent materials on optical fiber sensors 

      Ridruejo Muro, Adrián; Acha Morrás, Nerea de Upna; Elosúa Aguado, César Upna; Matías Maestro, Ignacio Upna; Arregui San Martín, Francisco Javier Upna (Hindawi Publishing Corporation, 2016)   Artículo / Artikulua  OpenAccess
      A method is proposed to determine lifetime of luminescent emissions based on the phase shift measurement employing the digitalized Lissajous representation: this diagram has been typically used with analogical algorithms, ...
    • Optimized strain long-period fiber grating (LPFG) sensors operating at the dispersion turning point 

      Del Villar, Ignacio Upna; Fuentes, Omar; Chiavaioli, Francesco; Corres Sanz, Jesús María Upna; Matías Maestro, Ignacio Upna (IEEE, 2018)   Artículo / Artikulua  OpenAccess
      Two phenomena for enhancing the sensitivity of longperiod fiber gratings are combined toward an increase of the sensitivity to strain of this type of devices: the dispersion turning point (DTP) and the cladding diameter ...
    • Optimizing interoperability between video-oculographic and electromyographic systems 

      Navallas Irujo, Javier Upna; Ariz Galilea, Mikel Upna; Villanueva Larre, Arantxa Upna; San Agustín, Javier; Cabeza Laguna, Rafael Upna (Rehabilitation Research & Development Service, 2011)   Artículo / Artikulua  OpenAccess
      A new system is presented that enhances the interoperability between a video-oculographic (VOG) system for mouse movement control and an electromyographic (EMG) system for mouse click detection. The proposed VOG-EMG system ...
    • Orthogonally polarized optical single sideband modulation for microwave photonics processing using stimulated Brillouin scattering 

      Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (Optical Society of America, 2010)   Artículo / Artikulua  OpenAccess
      We present a novel technique to generate orthogonally polarized optical single sideband modulated signals. The modulation scheme is based on all optical stimulated Brillouin scattering processing of the optical carrier of ...
    • Overcoming non-local effects and Brillouin threshold limitations in Brillouin optical time domain sensors 

      Ruiz Lombera, Rubén; Urricelqui Polvorinos, Javier Upna; Sagüés García, Mikel Upna; Mirapeix, Jesús; López Higuera, José Miguel; Loayssa Lara, Alayn Upna (IEEE, 2015)   Artículo / Artikulua  OpenAccess
      We demonstrate, for the first time to our knowledge, a Brillouin optical time domain analysis (BOTDA) sensor that is able to operate with a probe power larger than the Brillouin threshold of the deployed sensing fiber ...
    • Parameter-independent control for battery chargers based on virtual impedance emulation 

      Urtasun Erburu, Andoni Upna; Berrueta Irigoyen, Alberto; Sanchis Gúrpide, Pablo Upna; Marroyo Palomo, Luis Upna (IEEE, 2018)   Artículo / Artikulua
      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 ...
    • 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 ...
    • 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 ...
    • 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 ...
    • Photonic crystal fiber temperature sensor based on quantum dot nanocoatings 

      Larrión Zabaleta, Beatriz; 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 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 ...