• Signal processing in ocean bottom seismographs for refraction seismology 

      Rodríguez Barbarin, Iban; Mànuel Lázaro, Antonio; Carlosena García, Alfonso Upna; Bermúdez, Antoni; Río, Joaquín del; Panahi, Shahram Shariat (IEEE, 2006)   Artículo / Artikulua  OpenAccess
      This paper presents some experimental results on the application of signal processing techniques to underwater seismic signals. The novelty of this paper stems from the fact that it is the first paper, to the best of the ...
    • Simple modelling of DGS to design 1D-PBG low-pass filters 

      Garde Irigoyen, Ieltxu Aitor Upna; Yábar, Miguel Javier; Río Bocio, Carlos del Upna (Wiley, 2003)   Artículo / Artikulua  OpenAccess
      The use of defected ground structures (DGS) is being intensively explored by the microwave filter designer community. The DGSs are one possible implementation of a 1D Photonic Band Gap (1D-PBG) where some defect structures ...
    • Simplifying the feeding network for multi-beam circular antenna arrays by using corps 

      Panduro, Marco A.; Río Bocio, Carlos del Upna (EMW Publishing, 2011)   Artículo / Artikulua  OpenAccess
      An innovative way to analyze the design of beam-forming networks (BFN) for scannable multi-beam circular antenna arrays using the CORPS (Coherently Radiating Periodic Structures) concept is introduced. This design of ...
    • Simultaneous measurement of humidity and vibration based on a nanowire sensor system using Fast Fourier Transform technique 

      Rota Rodrigo, Sergio Upna; López Aldaba, Aitor Upna; Pérez Herrera, Rosa Ana Upna; López Bautista, María del Carmen; Esteban, Óscar; López-Amo Sáinz, Manuel Upna (IEEEOptical Society of America, 2016)   Artículo / Artikulua  OpenAccess
      This paper presents a new sensor system for vibration and relative humidity measurements based on its interaction with the evanescent field of a microwire. The interrogation of the sensing head is carried out by monitoring ...
    • Single-longitudinal mode laser structure based on a very narrow filtering technique 

      Rodríguez Cobo, L.; Quintela, M. A.; Rota Rodrigo, Sergio Upna; López-Amo Sáinz, Manuel Upna; López Higuera, José Miguel (Optical Society of America, 2013)   Artículo / Artikulua  OpenAccess
      A narrow filtering technique based on the spectral overlapping of two uniform FBGs and applied to obtain a Single Longitudinal Mode (SLM) laser is proposed and demonstrated in this work. The two FBGs are spectrally detuned ...
    • 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.; López Higuera, José Miguel; 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 ...
    • A slow light fishnet-like absorber in the millimeter-wave range 

      Navarro Cía, Miguel Upna; Torres Landívar, Víctor Upna; Beruete Díaz, Miguel Upna; Sorolla Ayza, Mario Upna (EMW Publishing, 2011)   Artículo / Artikulua  OpenAccess
      A novel route to achieve a narrowband free-space electromagnetic absorber in any range of the spectrum based on stacked subwavelength hole arrays is proposed. The absorption is obtained by means of a slow light mode inside ...
    • Small wind turbines sensorless MPPT: robustness analysis and lossless approach 

      Urtasun Erburu, Andoni Upna; Sanchis Gúrpide, Pablo Upna; Marroyo Palomo, Luis Upna (IEEE, 2014)   Artículo / Artikulua  OpenAccess
      The configuration Permanent Magnet Synchronous Generator (PMSG) with diode bridge is frequently used in small Wind Energy Conversion Systems (WESC) thanks to its reliability and low cost. In order to perform a sensorless ...
    • Soret fishnet metalens antenna 

      Orazbayev, Bakhtiyar Upna; Beruete Díaz, Miguel Upna; Pacheco Peña, Víctor Upna; Crespo López, Gonzalo; Teniente Vallinas, Jorge Upna; Navarro Cía, Miguel Upna (Springer Nature, 2015)   Artículo / Artikulua  OpenAccess
      At the expense of frequency narrowing, binary amplitude-only diffractive optical elements emulate refractive lenses without the need of large profiles. Unfortunately, they also present larger Fresnel reflection loss ...
    • Spatial characterization of radio propagation channel in urban vehicle-to-infrastructure environments to support WSNs deployment 

      Granda, Fausto; Azpilicueta Fernández de las Heras, Leyre Upna; Vargas Rosales, César; López Iturri, Peio Upna; Aguirre Gallego, Erik Upna; Astrain Escola, José Javier Upna; Villadangos Alonso, Jesús Upna; Falcone Lanas, Francisco Javier Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      Vehicular ad hoc Networks (VANETs) enable vehicles to communicate with each other as well as with roadside units (RSUs). Although there is a significant research effort in radio channel modeling focused on vehicle-to-vehicle ...
    • Spectral evolution with incremental nanocoating of long period fiber gratings 

      Del Villar, Ignacio Upna; Corres Sanz, Jesús María Upna; Achaerandio, Miguel Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (Optical Society of America, 2006)   Artículo / Artikulua  OpenAccess
      The incremental deposition of a thin overlay on the cladding of a long-period fiber grating (LPFG) induces important resonance wavelength shifts in the transmission spectrum. The phenomenon is proved theoretically with ...
    • Split ring resonator-based left-handed coplanar waveguide 

      Martín, 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 ...
    • State-of-charge-based droop control for stand-alone AC supply systems with distributed energy storage 

      Urtasun Erburu, Andoni Upna; Sanchis 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 ...
    • A stopband filter design using a 1-D non-periodic defected ground structure 

      Garde Irigoyen, Ieltxu Aitor Upna; Río Bocio, Carlos del Upna (Wiley, 2003)   Artículo / Artikulua  OpenAccess
      The one-dimensional (1-D) defected ground structure is used to control the cutoff frequency characteristic. In this paper three non-periodic filters are built, in order to show the versatility of the DGS. Five unit cells ...
    • Strategies for fabrication of hydrogen peroxide sensors based on electrostatic self-assembly (ESA) method 

      Del Villar, Ignacio Upna; Matías Maestro, Ignacio Upna; Arregui San Martín, Francisco Javier Upna; Echeverría Morrás, Jesús Upna; Claus, Richard O. (Elsevier, 2004)   Artículo / Artikulua  OpenAccess
      An optical fiber sensor has been fabricated for detection of 5 M–0.1mM concentrations of hydrogen peroxide with a linear response. The deposition method used is electrostatic self-assembly (ESA) of polymer cationic and ...
    • Strong lateral displacement in polarization anisotropic extraordinary transmission metamaterial 

      Beruete Díaz, Miguel Upna; Navarro Cía, Miguel Upna; Sorolla Ayza, Mario Upna (IOP Publishing Ltd, 2010)   Artículo / Artikulua  OpenAccess
      In this paper, a deep numerical as well as experimental study of the anisotropy response of extraordinary transmission metamaterials constructed by stacking subwavelength hole arrays is presented. Two-dimensional (2D) ...
    • Study and optimization of self-assembled polymeric multilayer structures with neutral red for pH sensing applications 

      Goicoechea Fernández, Javier Upna; Arregui San Martín, Francisco Javier Upna; Corres Sanz, Jesús María Upna; Matías Maestro, Ignacio Upna (Hindawi / Wiley, 2008)   Artículo / Artikulua  OpenAccess
      The characterization of nanostructured thin films is critical in the design and fabrication of optical sensors. Particularly, this work is a detailed study of the properties of layer-by-layer electrostatic self-assembled ...
    • Study of optical fiber sensors for cryogenic temperature measurements 

      Miguel Soto, Verónica de; Leandro González, Daniel Upna; López Aldaba, Aitor Upna; Beato López, Juan Jesús; Pérez de Landazábal Berganzo, José Ignacio; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; López-Amo Sáinz, Manuel Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      In this work, the performance of five different fiber optic sensors at cryogenic temperatures has been analyzed. A photonic crystal fiber Fabry-Pérot interferometer, two Sagnac interferometers, a commercial fiber Bragg ...
    • Superbackscattering antenna arrays 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (IEEE, 2015)   Artículo / Artikulua  OpenAccess
      This article discusses the theory, design and practical implementation of superbackscattering antenna arrays. In analogy with Uzkov’s maximal directivity theorem, it is demonstrated that the maximal backscattering ...
    • Surface waves of finite size electromagnetic band gap woodpile structures 

      Ederra Urzainqui, Íñigo Upna; Iriarte Galarregui, Juan Carlos Upna; Gonzalo García, Ramón Upna (EMW Publishing, 2011)   Artículo / Artikulua  OpenAccess
      This paper studies the surface modes at the interface of finite size Electromagnetic Band Gap (EBG) woodpile structures. The impact of different types of woodpile terminations on the properties of these surface modes is ...