Now showing items 216-235 of 292

    • Radio characterization for ISM 2.4 GHz wireless sensor networks for judo monitoring applications 

      López Iturri, Peio Upna; Aguirre Gallego, Erik Upna; Azpilicueta Fernández de las Heras, Leyre Upna; Astrain Escola, José Javier Upna; Villadangos Alonso, Jesús Upna; Falcone Lanas, Francisco Javier Upna (MDPI, 2014)   Artículo / Artikulua  OpenAccess
      In this work, the characterization of the radio channel for ISM 2.4GHz Wireless Sensor Networks (WSNs) for judo applications is presented. The environments where judo activity is held are usually complex indoor scenarios ...
    • Real-time simulation technique of a microgrid model for DER penetration 

      Mentesidi, Konstantina; Rikos, Evangelos; Kleftakis, Vasilis; Kotsampopoulos, Panos; Aguado Alonso, Mónica Upna (EAI, 2014)   Artículo / Artikulua  OpenAccess
      Comprehensive analysis of Distributed Energy Resources (DER) integration requires tools that provide computational power and flexibility. In this context, throughout this paper PHIL simulations are performed to emulate the ...
    • Recent developments in fiber optics humidity sensors 

      Ascorbe Muruzabal, Joaquín Upna; Corres Sanz, Jesús María Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      A wide range of applications such as health, human comfort, agriculture, food processing and storage, and electronic manufacturing, among others, require fast and accurate measurement of humidity. Sensors based on optical ...
    • Rectangular waveguide filters with meandered topology 

      Teberio Berdún, Fernando Upna; Percaz Ciriza, Jon Mikel Upna; Arregui Padilla, Iván Upna; Martín Iglesias, Petronilo; Lopetegui Beregaña, José María Upna; Gómez Laso, Miguel Ángel Upna; Arnedo Gil, Israel Upna (IEEE, 2018)   Artículo / Artikulua
      In this paper, a new topology for rectangular waveguide bandpass and low-pass filters is presented. A simple, accurate, and robust design technique for these novel meandered waveguide filters is provided. The proposed ...
    • Refractometric sensors based on multimode interference in a thin-film coated singlemode– multimode–single-mode structure with reflection configuration 

      Del Villar, Ignacio Upna; Socorro Leránoz, Abián Bentor Upna; Corres Sanz, Jesús María Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (Optical Society of America, 2014)   Artículo / Artikulua  OpenAccess
      Thin-film coated single-mode–multimode–single-mode (SMS) structures have been analyzed both theoretically and experimentally with the aim of detecting different refractive indices. By adequate selection of the thickness ...
    • Regular and anomalous extraordinary optical transmission at the THz-gap 

      Kuznetsov, Sergei A.; Navarro Cía, Miguel Upna; Kubarev, V. V.; Gelfand, A. V.; Beruete Díaz, Miguel Upna; Campillo, Igor; Sorolla Ayza, Mario Upna (Optical Society of America, 2009)   Artículo / Artikulua  OpenAccess
      In this paper Anomalous Extraordinary Transmission (ET) is reported for s-polarization of low loss doubly periodic subwavelength hole arrays patterned on polypropylene (PP) substrates by conventional contact photolithography ...
    • Remote (250 km) fiber Bragg grating multiplexing system 

      Fernández Vallejo, Montserrat Upna; Rota Rodrigo, Sergio Upna; López-Amo Sáinz, Manuel Upna (MDPI, 2011)   Artículo / Artikulua  OpenAccess
      We propose and demonstrate two ultra-long range fiber Bragg grating (FBG) sensor interrogation systems. In the first approach four FBGs are located 200 km from the monitoring station and a signal to noise ratio of 20 dB ...
    • Remote-time division multiplexing of bending sensors using a broadband light source 

      Bravo Acha, Mikel Upna; López-Amo Sáinz, Manuel Upna (Hindawi Publishing Corporation, 2012)   Artículo / Artikulua  OpenAccess
      This work experimentally demonstrates a remote sensing network which interrogates bending sensors using time-division multiplexing techniques and a broadband light source. The bending sensors are located 50 km away from ...
    • Resolution capabilities of future THz cameras 

      Lizarraga Cubillos, Juan Camilo Upna; Río Bocio, Carlos del Upna (Radioengineering Society, 2011)   Artículo / Artikulua  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 ...
    • Resonances in coated long period fiber gratings and cladding removed multimode optical fibers: a comparative study 

      Del Villar, Ignacio Upna; Ruiz Zamarreño, Carlos Upna; Hernáez Sáenz de Zaitigui, Miguel Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (Optical Society of America, 2010)    OpenAccess
      Two optical fiber devices have been coated in parallel: a long period fiber grating (LPFG) and a cladding-removed multimode optical fiber (CRMOF). The progressive coating of the LPFG by means of the layer-by-layer ...
    • Resonant quasi-periodic structure for rectangular waveguide technology with wide stopband and band-pass behavior 

      Arregui Padilla, Iván Upna; Teberio Berdún, Fernando Upna; Arnedo Gil, Israel Upna; Percaz Ciriza, Jon Mikel Upna; Gómez Torrent, Adrián Upna; Chudzik, Magdalena Upna; Gómez Laso, Miguel Ángel Upna; Lopetegui Beregaña, José María Upna (EMW Publishing, 2016)   Artículo / Artikulua  OpenAccess
      In this paper, a novel quasi-periodic structure for rectangular waveguide technology is proposed. The constituent unit cells of the structure feature a resonant behavior, providing high attenuation levels in the stopband ...
    • Response of complementary split ring resonators in composite stratified substrate integrated waveguide 

      Pérez Escudero, José Manuel Upna; Jarauta Ayensa, Eduardo Upna; Falcone Lanas, Francisco Javier Upna; Beruete Díaz, Miguel Upna (American Institute of Physics, 2017)   Artículo / Artikulua  OpenAccess
      In this work, the behavior of a Complementary Split Ring Resonator (CSRR) operating within the quasi-static resonance regime and embedded in a composite stratified Substrate Integrated Waveguide (SIW) with two different ...
    • Review on electromagnetic band gap technology and applications 

      Maagt, Peter de; Gonzalo García, Ramón Upna; Vardaxoglou, J. (URSI, 2004)   Artículo / Artikulua  OpenAccess
      This paper reviews the primary application areas of Electromagnetic BandGap (EBG) technology at microwave and (sub)millimetre wave frequencies. Examples of EBG configurations in the microwave region are shown and include ...
    • Robust fiber-optic sensor networks 

      Pérez Herrera, Rosa Ana Upna; Fernández Vallejo, Montserrat Upna; López-Amo Sáinz, Manuel Upna (Springer, 2012)   Artículo / Artikulua  OpenAccess
      The ability to operate despite failure will become increasingly important as the use of optical sensor networks grows, and the amount of sensing information to be handled by a sensor network is increasing, especially for ...
    • Routing with classical corrugated waveguide low-pass filters with embedded bends 

      Teberio Berdún, Fernando Upna; Percaz Ciriza, Jon Mikel Upna; Arregui Padilla, Iván Upna; Martín Iglesias, Petronilo; Lopetegui Beregaña, José María Upna; Gómez Laso, Miguel Ángel Upna; Arnedo Gil, Israel Upna (EMW Publishing, 2018)   Artículo / Artikulua  OpenAccess
      A very simple design method to embed routing capabilities in classical corrugated filters is presented in this paper. The method is based on the calculation of the heights and lengths of the so-called filters design ...
    • Second-order non-local effects mitigation in BOTDA sensors by tracking the BFS profile 

      Mompó Roselló, Juan José Upna; Iribas Pardo, Haritz Upna; Urricelqui Polvorinos, Javier Upna; Loayssa Lara, Alayn Upna (SPIE, 2017)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      We demonstrate a technique to mitigate the residual second-order non-local effects in Brillouin optical time-domain analysis (BOTDA) sensors in which the Brillouin frequency shift (BFS) profile is not uniform along the ...
    • Second-order nonlocal effects mitigation in Brillouin optical time-domain analysis sensors by tracking the Brillouin frequency shift profile of the fiber 

      Mompó Roselló, Juan José Upna; Iribas Pardo, Haritz Upna; Urricelqui Polvorinos, Javier Upna; Loayssa Lara, Alayn Upna (IEEE, 2017)   Artículo / Artikulua  OpenAccess
      We report on an additional limitation that has been found in Brillouin optical time-domain analysis (BOTDA) sensors due to the so-called second-order nonlocal effects (NLE). Second-order NLE appear in BOTDA setups that ...
    • Sensitivity enhancement experimental demonstration using a low cutoff wavelength SMS modified structure coated with a pH sensitive film 

      Rodríguez-Rodríguez, W.E.; Del Villar, Ignacio Upna; Ruiz Zamarreño, Carlos Upna; Matías Maestro, Ignacio Upna; Arregui San Martín, Francisco Javier Upna; Rodríguez Rodríguez, Adolfo Josué; Domínguez-Cruz, R.F. (Elsevier, 2018)   Artículo / Artikulua
      The multimode interference (MMI) effect in a single mode-multimode-single mode (SMS) can be used fordevelopment of wavelength shift detection based sensors. In this work, the focus is centered on obtainingwavelength shifts ...
    • Sensitivity enhancement in low cutoff wavelength long-period fiber gratings by cladding diameter reduction 

      Del Villar, Ignacio Upna; Partridge, Matthew; Rodríguez, Wenceslao; Fuentes, Omar; Socorro Leránoz, Abián Bentor Upna; Díaz Lucas, Silvia Upna; Corres Sanz, Jesús María Upna; James, Stephen; Tatam, Ralph (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      The diameter of long-period fiber gratings (LPFGs) fabricated in optical fibers with a low cutoff wavelength was be reduced by hydrofluoric acid etching, enhancing the sensitivity to refractive index by more than a factor ...
    • Sensitivity improvement of a humidity sensor based on silica nanospheres on a long-period fiber grating 

      Viegas, Diana; Goicoechea Fernández, Javier Upna; Santos, José Luís; Araújo, Francisco Moita; Ferreira, Luis Alberto; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (MDPI, 2009)   Artículo / Artikulua  OpenAccess
      This work addresses a new configuration that improves the sensitivity of a humidity sensor based on a long-period fiber grating coated with a SiO(2)-nanospheres film. An intermediate higher refractive index overlay, ...