Now showing items 16-35 of 50

    • General synthesis of tapered matching sections for single mode operation using the coupled-mode theory 

      Percaz Ciriza, Jon Mikel Upna; Arnedo Gil, Israel Upna; Arregui Padilla, Iván Upna; Teberio Berdún, Fernando Upna; Martín Iglesias, Petronilo; Gómez Laso, Miguel Ángel Upna; Lopetegui Beregaña, José María Upna (IEEE, 2019)   Artículo / Artikulua
      In this paper, a novel and general method to synthetize microwave waveguide tapers intended for single mode operation is proposed. The technique is based on the use of an exact series solution of the inverse scattering ...
    • Generation of lossy mode resonances in planar waveguides toward development of humidity sensors 

      Fuentes, Omar; Corres Sanz, Jesús María Upna; Matías Maestro, Ignacio Upna; Del Villar, Ignacio Upna (IEEE, 2019)   Artículo / Artikulua
      Lossy mode resonances (LMRs) are typically obtained with optical fibre. The Kretschmann configuration is an alternative but LMRs are generated with angles approaching grazing incidence. In this work, a new setup is explored, ...
    • Grating lobes in higher-order correlation functions of arrays of quantum emitters: directional photon bunching versus correlated directions 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Ziolkowski, Richard W. (MDPI, 2019)   Artículo / Artikulua  OpenAccess
      Recent advances in nanofabrication and optical manipulation techniques are making it possible to build arrays of quantum emitters with accurate control over the locations of their individual elements. In analogy with ...
    • Integration of autonomous wireless sensor networks in academic school gardens 

      López Iturri, Peio Upna; Celaya Echarri, Mikel; Azpilicueta Fernández de las Heras, Leyre Upna; Aguirre Gallego, Erik Upna; Astrain Escola, José Javier Upna; Villadangos Alonso, Jesús Upna; Falcone Lanas, Francisco Javier Upna (MDPI, 2018)   Artículo / Artikulua  OpenAccess
      In this work, the combination of capabilities provided by Wireless Sensor Networks (WSN) with parameter observation in a school garden is employed in order to provide an environment for school garden integration as a ...
    • Intelligent control of wind-assisted PHEVs smart charging station 

      Hassan, Syed Zulqadar; Kamal, Tariq; Riaz, Muhammad Hussnain; Shah, Syed Aamir Hussain; Ali, Hina Gohar; Riaz, Muhammad Tanveer; Sarmad, Muhammad; Zahoor, Amir; Khan, Muhammad Abbas; Pascual Miqueleiz, Julio María Upna (MDPI, 2019)   Artículo / Artikulua  OpenAccess
      Two technology opportunities, integration of renewable energy sources and the electrification of vehicles are being encouraged to reduce dependency on fossil fuels and pollution problems. Nevertheless, the huge increase ...
    • Interaction between closely packed array antenna elements using meta-surface for applications such as MIMO systems and synthetic aperture radars 

      Alibakhshikenari, Mohammad; Virdee, Bal S.; Shukla, Panchamkumar; See, Chan H.; Abd-Alhameed, Raed; Khalily, Mohsen; Falcone Lanas, Francisco Javier Upna; Limiti, Ernesto (Wiley, 2018)   Artículo / Artikulua  OpenAccess
      The paper presents a technique to enhance the isolation between adjacent radiating elements that is common in densely packed antenna arrays. Such antennas provide frequency beam-scanning capability needed in multiple-input ...
    • Labyrinth metasurface absorber for ultra-high-sensitivity terahertz thin film sensing 

      Jáuregui López, Irati Upna; Rodríguez Ulibarri, Pablo Upna; Urrutia Azcona, Aitor Upna; Kuznetsov, Sergei A.; Beruete Díaz, Miguel Upna (Wiley, 2018)   Artículo / Artikulua  OpenAccess
      In this work, a labyrinth metasurface sensor operating at the low‐frequency edge of the THz band is presented. Its intricate shape leads to a high electric field confinement on the surface of the structure, resulting in ...
    • Labyrinth metasurface for biosensing applications: numerical study on the new paradigm of metageometries 

      Jáuregui López, Irati Upna; Rodríguez Ulibarri, Pablo Upna; Kuznetsov, Sergei A.; Quemada Mayoral, Carlos Upna; Beruete Díaz, Miguel Upna (MDPI, 2019)   Artículo / Artikulua  OpenAccess
      The use of metasurfaces operating in the terahertz regime as biosensor devices has attracted increased interest in recent years due to their enhanced sensitivity and more accurate detection capability. Typical designs are ...
    • Layer-by-layer nano-assembly: a powerful tool for optical fiber sensing applications 

      Rivero Fuente, Pedro J. Upna; Goicoechea Fernández, Javier Upna; Arregui San Martín, Francisco Javier Upna (MDPI, 2019)   Artículo / Artikulua  OpenAccess
      The ability to tune the composition of nanostructured thin films is a hot topic for the design of functional coatings with advanced properties for sensing applications. The control of the structure at the nanoscale level ...
    • Lossy mode resonance optical sensors based on indium-gallium-zinc oxide thin film 

      Ozcariz Celaya, Aritz Upna; Dominik, Magdalena; Smietana, Mateusz; Ruiz Zamarreño, Carlos Upna; Del Villar, Ignacio Upna; Arregui San Martín, Francisco Javier Upna (Elsevier, 2019)   Artículo / Artikulua
      This work discusses an application of electrically conductive and optically transparent indium-gallium-zinc oxide (IGZO) thin films for fabrication of lossy mode resonance (LMR) based optical fiber refractometers. The films ...
    • Narrowband characterization of near-ground radio channel for wireless sensors networks at 5G-IoT bands 

      Klaina, Hicham; Vazquez Alejos, Ana; Aghzout, Otman; Falcone Lanas, Francisco Javier Upna (MDPI, 2018)   Artículo / Artikulua  OpenAccess
      In this contribution, a narrowband radio channel model is proposed for rural scenarios in which the radio link operates under near-ground conditions for application in wireless sensor networks dedicated to smart agriculture. ...
    • On the design and performance evaluation of automatic traffic report generation systems with huge data volumes 

      Vega, Carlos; Miravalls-Sierra, Eduardo; Julián-Moreno, Guillermo; López de Vergara, Jorge E.; Magaña Lizarrondo, Eduardo Upna; Aracil Rico, Javier Upna (Wiley, 2018)   Artículo / Artikulua  OpenAccess
      In this paper we analyze the performance issues involved in the generation of automated traffic reports for large IT infrastructures. Such reports allow the IT manager to proactively detect possible abnormal situations ...
    • On the performance of an ENZ-based sensor using transmission line theory and effective medium approach 

      Pacheco-Peña, Víctor Upna; Beruete Díaz, Miguel Upna; Rodríguez Ulibarri, Pablo Upna; Engheta, Nader (IOP Publishing, 2019)   Artículo / Artikulua  OpenAccess
      In this paper we perform an in-depth theoretical studyofa sensing platform based on epsilon-near- zero (ENZ) metamaterials. The structure proposed for sensing is a narrow metallic waveguide channel. An equivalent circuit ...
    • On the stability of advanced power electronic converters: the Generalized Bode Criterion 

      Lumbreras Magallón, David Upna; Barrios Rípodas, Ernesto Upna; Urtasun Erburu, Andoni Upna; Ursúa Rubio, Alfredo Upna; Marroyo Palomo, Luis Upna; Sanchis Gúrpide, Pablo Upna (IEEE, 2019)   Artículo / Artikulua  OpenAccess
      A key factor in the design of power electronic converters is the development of control systems and, in particular, the determination of their stability. Due to ease of application, the Bode criteria are currently the most ...
    • Optical fiber lasers assisted by microdrilled optical fiber tapers 

      Pérez Herrera, Rosa Ana Upna; Pallarés Aldeiturriaga, D.; Júdez Colorado, Aitor Upna; Rodríguez Cobo, L.; López-Amo Sáinz, Manuel Upna; López Higuera, José Miguel (Optical Society of America, 2019)   Artículo / Artikulua
      In this Letter, we present an analysis of the backscattering generated in a microdrilled tapered fiber within a short-linear-cavity fiber laser. We propose and experimentally demonstrate a fiber cavity laser based on a ...
    • Photonic nanojets with mesoscale high-index dielectric particles 

      Pacheco-Peña, Víctor Upna; Beruete Díaz, Miguel Upna (AIP Publishing, 2019)   Artículo / Artikulua  OpenAccess
      In this work, we demonstrate the ability of high-index dielectric particles immersed in air to generate photonic nanojets with extreme resolution (∼0.06λ0). Both 2D (cylindrical) and 3D (spherical) particles are analyzed, ...
    • Quasi-distributed vibration sensing using OFDR and weak reflectors 

      Zhu, Mengshi; Leandro González, Daniel Upna; López-Amo Sáinz, Manuel Upna; Murayama, Hideaki (Optical Soc iety of America, 2019)   Artículo / Artikulua
      The authors proposed a quasi-distributed vibration sensing technique using in-line weak reflectors and optical frequency domain reflectometry (OFDR). As a result, they achieved an 8 kHz measurable vibration frequency with ...
    • Ransomware early detection by the analysis of file sharing traffic 

      Morató Osés, Daniel Upna; Berrueta Irigoyen, Eduardo Upna; Magaña Lizarrondo, Eduardo Upna; Izal Azcárate, Mikel Upna (Elsevier, 2018)   Artículo / Artikulua  OpenAccess
      Crypto ransomware is a type of malware that locks access to user files by encrypting them and demands a ransom in order to obtain the decryption key. This type of malware has become a serious threat for most enterprises. ...
    • Real time measuring system of multiple chemical parameters using microstructured optical fibers based sensors 

      López Aldaba, Aitor Upna; López Torres, Diego Upna; Elosúa Aguado, César Upna; Arregui San Martín, Francisco Javier Upna; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; López-Amo Sáinz, Manuel Upna (IEEE, 2018)   Artículo / Artikulua  OpenAccess
      In this paper, a multiplexing system for simultaneous interrogation of optical fiber sensors which measure different parameters is presented and validated. The whole system has been tested with 6 different sensing heads ...
    • Remote access protocols for Desktop-as-a-Service solutions 

      Magaña Lizarrondo, Eduardo Upna; Sesma Gracia, Iris Upna; Morató Osés, Daniel Upna; Izal Azcárate, Mikel Upna (Public Library of Science, 2019)   Artículo / Artikulua  OpenAccess
      The use of remote desktop services on virtualized machines is a general trend to reduce the cost of desktop seats. Instead of assigning a physical machine with its operating system and software to each user, it is considerably ...