• Characterization of microring filters for differential group delay applications 

      Doménech, D.; Chamorro Posada, P.; Fraile Pelaez, F.J.; Erro Betrán, María José; Tainta Ausejo, Santiago; Muriel, M.A.; Baños, R.; Bolten, J.; Kleinjans, H. (IEEEOptical Society of America, 2017)   Artículo / Artikulua
      The longitudinal offset technique permits to improve the accuracy of the coupling coefficients of integrated directional couplers and provides designs that can be easily implemented with current fabrication tolerances. ...
    • High aperture efficiency wide corrugations bull’s-eye antenna working at 60 GHz 

      Beaskoetxea Gartzia, Unai; Beruete Díaz, Miguel (IEEE, 2017)   Artículo / Artikulua
      A full metallic Bull’s-Eye (BE) antenna operating at 60 GHz is numerically and experimentally analyzed. The antenna presents wide grooves, rather than narrow ones, which support higher order resonances that lead to a large ...
    • Response of complementary split ring resonators in composite stratified substrate integrated waveguide 

      Pérez Escudero, José Manuel; Jarauta Ayensa, Eduardo; Falcone Lanas, Francisco Javier; Beruete Díaz, Miguel (American Institute of Physics, 2017)   Artículo / Artikulua
      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 ...
    • Nonbianisotropic complementary split ring resonators as angular selective metasurfaces 

      Rodríguez Ulibarri, Pablo; Beruete Díaz, Miguel (2017)   Artículo / Artikulua
      In this work, a metasurface with unconventional angular performance and composed by a nonbianisotropic complementary split ring resonator (NB-CSRR) is analyzed numerically and experimentally. A numerical study comparing ...
    • Cyclic coding for Brillouin optical time-domain analyzers using probe dithering 

      Iribas Pardo, Haritz; Loayssa Lara, Alayn; Sauser, Florian; Llera, Miguel; Le Floch, Sébastien (Optical Society of America, 2017)   Artículo / Artikulua
      We study the performance limits of mono-color cyclic coding applied to Brillouin optical time-domain analysis (BOTDA) sensors that use probe wave dithering. BOTDA analyzers with dithering of the probe use a dual-probe-sideband ...
    • 3D-printed 96 GHz bull’s-eye antenna with off-axis beaming 

      Beaskoetxea Gartzia, Unai; Maci, Stefano; Navarro Cía, Miguel; Beruete Díaz, Miguel (IEEE, 2017)   Artículo / Artikulua
      Reducing the profile, footprint and weight of antennas embarked on aircrafts, drones or satellites has been a long pursued objective. Here we tackle this issue by developing a millimeter-wave 96 GHz elliptical Bull’s-Eye ...
    • Metasurface-based ultrathin carpet cloaks for millimeter waves 

      Orazbayev, Bakhtiyar; Mohammadi Estakhri, Nasim; Alù, Andrea; Beruete Díaz, Miguel (2017)   Artículo / Artikulua
      A metasurface carpet cloak for millimetre-wave range with polarization independent performance is experimentally demonstrated. It is shown that the cloak is able to mimic the ground plane by fully restoring the amplitude ...
    • Optical fibre sensors using graphene-based materials: a review 

      Hernáez Sáenz de Zaitigui, Miguel; Ruiz Zamarreño, Carlos; Melendi Espina, Sonia; Bird, Liam; Mayes, Andrew; Arregui San Martín, Francisco Javier (MDPI, 2017)   Artículo / Artikulua
      Graphene and its derivatives have become the most explored materials since Novoselov and Geim (Nobel Prize winners for Physics in 2010) achieved its isolation in 2004. The exceptional properties of graphene have attracted ...
    • Challenges in wireless system integration as enablers for indoor context aware environments 

      López Iturri, Peio; Aguirre Gallego, Erik; Azpilicueta Fernández de las Heras, Leyre; Astrain Escola, José Javier; Villandangos Alonso, Jesús; Falcone Lanas, Francisco Javier (MDPI, 2017)   Artículo / Artikulua
      The advent of fully interactive environments within Smart Cities and Smart Regions requires the use of multiple wireless systems. In the case of user-device interaction, which finds multiple applications such as Ambient ...
    • Wideband backscattering reduction at terahertz using compound reflection grating 

      Orazbayev, Bakhtiyar; Rodríguez Ulibarri, Pablo; Beruete Díaz, Miguel (Optical Society of America, 2017)   Artículo / Artikulua
      Backscattering reduction is usually achieved by using either absorbers or diffractions gratings at the expense of a narrow bandwidth. In this paper, we propose a different strategy based on a metallic compound reflection ...
    • Experimental realization of an epsilon-near-zero graded-index metalens at terahertz frequencies 

      Pacheco Peña, Víctor; Engheta, Nader; Kuznetsov, Sergei A.; Gentselev, Alexandr; Beruete Díaz, Miguel (American Physical Society, 2017)   Artículo / Artikulua
      The terahertz band has been historically hindered by the lack of efficient generators and detectors, but a series of recent breakthroughs have helped to effectively close the “terahertz gap.” A rapid development of terahertz ...
    • One-way quasiplanar terahertz absorbers using nonstructured polar dielectric layers 

      Rodríguez Ulibarri, Pablo; Serebryannikov, Andriy; Beruete Díaz, Miguel (American Physical Society, 2017)   Artículo / Artikulua
      A concept of quasiplanar one-way transparent terahertz absorbers made of linear isotropic materials is presented. The resulting structure consists of a homogeneous absorbing layer of polar dielectric, GaAs, a dispersion-free ...
    • Sensitivity enhancement in low cutoff wavelength long-period fiber gratings by cladding diameter reduction 

      Villar Fernández, Ignacio del; Partridge, Matthew; Rodríguez, Wenceslao; Fuentes, Omar; Socorro Leránoz, Abián Bentor; Díaz Lucas, Silvia; Corres Sanz, Jesús María; James, Stephen; Tatam, Ralph (MDPI, 2017)   Artículo / Artikulua
      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 ...
    • Recent developments in fiber optics humidity sensors 

      Ascorbe Muruzabal, Joaquín; Corres Sanz , Jesús María; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio (MDPI, 2017)   Artículo / Artikulua
      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 ...
    • Spatial characterization of radio propagation channel in urban vehicle-to-infrastructure environments to support WSNs deployment 

      Granda, Fausto; Azpilicueta Fernández de las Heras, Leyre; Vargas Rosales, César; López Iturri, Peio; Aguirre Gallego, Erik; Astrain Escola, José Javier; Villandangos Alonso, Jesús; Falcone Lanas, Francisco Javier (MDPI, 2017)   Artículo / Artikulua
      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 ...
    • Humidity sensor based on Bragg gratings developed on the end facet of an optical fiber by sputtering of one single material 

      Ascorbe Muruzabal, Joaquín; Corres Sanz , Jesús María; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio (MDPI, 2017)   Artículo / Artikulua
      The refractive index of sputtered indium oxide nanocoatings has been altered just by changing the sputtering parameters, such as pressure. These induced changes have been exploited for the generation of a grating on the ...
    • ECOAL project: delivering solutions for integrated monitoring of coal-related fires supported on optical fiber sensing technology 

      Ribeiro, Joana; Viveiros, Duarte; Ferreira, João; López Gil, Alexia; Domínguez López, Alejandro; Martins, Hugo F.; Pérez Herrera, Rosa Ana; López Aldaba, Aitor; Duarte, Lia; Rodrigues Pinto, Ana Margarida; Martín López, Sonia; Baierl, Hardy; Jamier, Raphael; Rougier, Sébastien; Auguste, Jean-Louis; Teodoro, Ana Cláudia; Gonçalves, José Alberto; Esteban, Óscar; Santos, José Luís; Roy, Philippe; López-Amo Sáinz, Manuel; González Herráez, Miguel; Baptista, José Manuel; Flores, Deolinda (MDPI, 2017)   Artículo / Artikulua
      The combustion of coal wastes resulting from mining is of particular environmental concern, and the importance of proper management involving real-time assessment of their status and identification of probable evolution ...
    • Tillage effects on soil quality after three years of irrigation in Northern Spain 

      Apesteguía Barberena, Marcos; Virto Quecedo, Íñigo; Orcaray Echeverría, Luis; Bescansa Miquel, Paloma; Enrique Martín, Alberto; Imaz Gurruchaga, María José; Karlen, Douglas (MDPI, 2017)   Artículo / Artikulua
      Irrigation is being initiated on large areas of traditionally rainfed land to meet increasing global demand for food, feed, fiber and fuel. However, the consequences of this transition on soil quality (SQ) have scarcely ...
    • Broadband frequency and angular response of a sinusoidal bull’s eye antenna 

      Beaskoetxea Gartzia, Unai; Navarro Cía, Miguel; Beruete Díaz, Miguel (IOP Publishing, 2016)   Artículo / Artikulua
      A thorough experimental study of the frequency and beaming angle response of a metallic leaky-wave bull’s eye antenna working at 77 GHz with a sinusoidally corrugated profile is presented. The beam scanning property of ...
    • Producing and exploiting simultaneously the forward and backward coupling in EBG-assisted microstrip coupled lines 

      Percaz Ciriza, Jon Mikel; Chudzik, Magdalena; Arnedo Gil, Israel; Arregui Padilla, Iván; Teberio Berdún, Fernando; Gómez Laso, Miguel Ángel; Lopetegui Beregaña, José María (IEEE, 2016)   Artículo / Artikulua
      In this paper, a methodology is proposed for the design of EBG-assisted coupled line structures in microstrip technology, controlling independently the forward and backward coupling. It is based on the use of a ...