Envíos recientes

  • Dual-wavelength single-longitudinal-mode erbium fiber laser for temperature measurements 

    Díaz Lucas, Silvia Upna; López-Amo Sáinz, Manuel Upna (SPIE, 2014)   Artículo / Artikulua  OpenAccess
    A dual-wavelength erbium fiber laser with single-longitudinal-mode characteristic is proposed and demonstrated. The system uses a 7-m-long highly doped erbium-doped fiber as the primary gain medium while two fiber Bragg ...
  • Nanofilms on a hollow core fiber 

    Matías Maestro, Ignacio Upna; Bravo Larrea, Javier Upna; Arregui San Martín, Francisco Javier Upna; Corres Sanz, Jesús María Upna (SPIE, 2006)   Artículo / Artikulua  OpenAccess
    We experimentally study the behavior of one multimode fiber–hollow core fiber–multimode fiber structure when nanofilms are deposited on it with the aim of developing practical evanescent field-based devices, such as sensors, ...
  • Wideband unidirectional transmission with tunable sign-switchable refraction and deflection in nonsymmetric structures 

    Rodríguez Ulibarri, Pablo Upna; Beruete Díaz, Miguel Upna; Navarro Cía, Miguel Upna; Serebryannikov, Andriy E. (American Physical Society, 2013)   Artículo / Artikulua  OpenAccess
    A general theory of reciprocal unidirectional transmission with tunable sign-switchable refraction and deflection of outgoing wave in structures with broken spatial inversion symmetry is presented. Several coupling scenarios ...
  • Frozen mode from hybridized extraordinary transmission and Fabry-Perot resonances 

    Beruete Díaz, Miguel Upna; Rodríguez Ulibarri, Pablo Upna; Pacheco Peña, Víctor Upna; Navarro-Cía, M.; Serebryannikov, A. E. (American Physical Society, 2013)   Artículo / Artikulua  OpenAccess
    Frozen modes arising in stacked subwavelength hole arrays are studied in detail. Their origin is proved to be connected with the interaction between the extraordinary transmission resonance and the Fabry–Perot cavity mode. ...
  • Single-longitudinal-mode dual wavelength-switchable fiber laser based on superposed fiber bragg gratings 

    Pérez Herrera, Rosa Ana Upna; Rodriguez-Cobo, L.; Quintela, M. A.; Lopez Higuera, J. M.; López-Amo Sáinz, Manuel Upna (IEEE, 2015)   Artículo / Artikulua  OpenAccess
    n this work, a simple switchable dual-wavelength short-cavity fiber laser operating in a single-longitudinal-mode regime at room temperature and based on superposed fiber Bragg gratings is proposed and experimentally ...
  • Induction theorem analysis of resonant nanoparticles: design of a huygens source nanoparticle laser 

    Liberal Olleta, Íñigo; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (American Physical Society, 2014)   Artículo / Artikulua  OpenAccess
    We propose an advanced formulation of standard antenna theory for the basic investigation and design of resonant nanoparticles. This methodology is based on transforming the original scattering problem into a radiation ...
  • Lensing system and Fourier transformation using epsilon-near-zero metamaterials 

    Navarro Cía, Miguel Upna; Beruete Díaz, Miguel Upna; Sorolla Ayza, Mario Upna; Engheta, N. (American Physical Society, 2012)   Artículo / Artikulua  OpenAccess
    Metamaterials and metastructures with effective relative permittivity near zero exhibit unusual wave properties such as uniform phase distributions across such domains. Here we discuss the possibility of using ε-near-zero ...
  • Enhancement of the dynamic range in slope-assisted coherent brillouin optical time-domain analysis sensors 

    Mariñelarena Ollacarizqueta, Jon Upna; Urricelqui Polvorinos, Javier Upna; Loayssa Lara, Alayn Upna (IEEE, 2017)   Artículo / Artikulua  OpenAccess
    We present two techniques that provide an extension of the dynamic range of coherent Brillouin optical time-domain analysis (BOTDA) sensors for dynamic measurements. This type of BOTDA sensors rely on self-heterodyne ...
  • Dipolar resonances in conductive carbon micro-fibers probed by near-field terahertz spectroscopy 

    Khromova, Irina Upna; Navarro Cía, Miguel Upna; Brener, I.; Reno, J. L.; Ponomarev, A.; Mitrofanov, Oleg (AIP Publishing, 2015)   Artículo / Artikulua  OpenAccess
    We observe dipole resonances in thin conductive carbon micro-fibers by detecting an enhanced electric field in the near-field of a single fiber at terahertz (THz) frequencies. Time-domain analysis of the electric field ...
  • Geometry influence on the transmission spectra of dielectric single layers of spheres with different compactness 

    Andueza Unanua, Ángel María; Echeverría, R.; Morales Zimmermann, Paola Andrea Upna; Sevilla Moróder, Joaquín Upna (AIP Publishing, 2010)   Artículo / Artikulua  OpenAccess
    The transmission of spectra of different dielectric spheres single layer arrangements has been measured. High dielectric permittivity ε =7 spheres of several millimeters of diameter were used to build the samples whose ...
  • Transmission spectra changes produced by decreasing compactness of opal-like structures 

    Andueza Unanua, Ángel María; Echeverría, R.; Morales Zimmermann, Paola Andrea Upna; Sevilla Moróder, Joaquín Upna (AIP Publishing, 2009)   Artículo / Artikulua  OpenAccess
    Artificial opal-like structures based on spheres and colloidal particles have been fabricated in a controlled way, presenting optical band-gap properties in the optical frequency range. Nonclose packed artificial opals ...
  • 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 ...
  • Split ring resonator-based left-handed coplanar waveguide 

    Martı́n, F.; Bonache, J.; Falcone Lanas, Francisco Javier Upna; Sorolla Ayza, Mario Upna; Marqués, R. (AIP Publishing, 2003)   Artículo / Artikulua  OpenAccess
    In this letter, a planar left-handed propagating medium consisting of a coplanar waveguide (CPW) inductively coupled to split ring resonators (SRR) and periodically loaded with narrow metallic wires is proposed. The wires ...
  • 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 ...
  • 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 ...
  • Parameter-independent control for battery chargers based on virtual impedance emulation 

    Urtasun Erburu, Andoni Upna; Berrueta Irigoyen, Alberto; Sanchís 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 ...
  • A comprehensive model for lithium-ion batteries: from the physical principles to an electrical model 

    Berrueta Irigoyen, Alberto; Urtasun Erburu, Andoni Upna; Ursúa Rubio, Alfredo Upna; Sanchís Gúrpide, Pablo Upna (Elsevier, 2018)   Artículo / Artikulua
    The growing interest in e-mobility and the increasing installation of renewable energy-based systems are leading to rapid improvements in lithium-ion batteries. In this context, battery manufacturers and engineers require ...
  • 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 ...
  • State-of-charge-based droop control for stand-alone AC supply systems with distributed energy storage 

    Urtasun Erburu, Andoni Upna; Sanchís Gúrpide, Pablo Upna; Marroyo Palomo, Luis Upna (Elsevier, 2015)   Artículo / Artikulua  OpenAccess
    The droop method is an advantageous technique for stand-alone AC supply systems, allowing for power sharing among various inverters with no need for communication cables. However, in stand-alone systems with multiple ...
  • Control of a single-switch two-input buck converter for MPPT of two PV strings 

    Urtasun Erburu, Andoni Upna; Dah-Chuan Lu, Dylan (IEEE, 2015)   Artículo / Artikulua  OpenAccess
    In this paper, the Two-Input Buck (TIBuck) converter is proposed as the DC/DC stage for photovoltaic (PV) cascaded converters. This converter is attractive for this application because it is cost-effective and reliable and ...

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