Ara es mostren els items 8-27 de 254

    • A 3D printed lens antenna for 5G applications 

      Ballesteros, Christian; Maestre, Marcos; Santos Blanco, M. Concepción; Romeu Robert, Jordi; Jofre Roca, Lluís (Institute of Electrical and Electronics Engineers (IEEE), 2019)
      Comunicació de congrés
      Accés obert
      A switchable multi-antenna architecture for lens-assisted beamsteering in the Ka-band region allocated for 5G communications (24-30 GHz) is proposed. The radiating elements are bow-tie antennas mounted with a 3D printed ...
    • A contact-less small antenna characterization through impedance modulation 

      Monsalve Carcelen, Beatriz; Blanch Boris, Sebastián; Romeu Robert, Jordi; Jofre Roca, Lluís (IEEE Press. Institute of Electrical and Electronics Engineers, 2009)
      Text en actes de congrés
      Accés obert
      In smalls antennas S-parameters measurements are highly influenced by the measurement equipment as well as the environment. In order to avoid this inconvenience, a wireless and non-invasive characterization setup is required. ...
    • A cylindrical array for fast microwave tomography 

      de los Reyes, Elías; Jofre Roca, Lluís; Broquetas Ibars, Antoni; Elias Fusté, Antoni; Cardama Aznar, Ángel (Unión Científica Internacional de Radio (URSI), 1987)
      Text en actes de congrés
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    • A cylindrical system for quasy-real time microwave tomography 

      Jofre Roca, Lluís; Reyes, E De Los; Ferrando Bataller, Miquel; Elias Fusté, Antoni; Romeu Robert, Jordi; Baquero, M; Rius Casals, Juan Manuel (Institute of Electrical and Electronics Engineers (IEEE), 1986)
      Text en actes de congrés
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      A cylindrical system for biomedical microwave tomography is presented. The circular algorithms and some numerical reconstructions are discussed. Finally the experimental set-up is described and some preliminary measurements ...
    • A dynamic load balancing method for the evaluation of chemical reaction rates in parallel combustion simulations 

      Muela Castro, Jordi; Borrell Pol, Ricard; Ventosa Molina, Jordi; Jofre Roca, Lluís; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David (Elsevier, 2019-08-15)
      Article
      Accés obert
      The development and assessment of an efficient parallelization method for the evaluation of reaction rates in combustion simulations is presented. Combustion simulations where the finite-rate chemistry model is employed ...
    • A figure of merit to assess the performance of photoconductive antennas at terahertz band 

      Romeu Robert, Jordi; Cea Falcó, Marc de; Jofre Roca, Lluís; Yazgan, Ahmet Utku (Institute of Electrical and Electronics Engineers (IEEE), 2017)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Photoconductive antennas are one of the most efficient ways to radiate and receive EM waves around the 1 THz frequency band. The physical processes involved in photoconductive terahertz signal generation are complex enough ...
    • A figure-of-merit for pattern reconfigurable antennas 

      Rodrigo López, Daniel; Romeu Robert, Jordi; Capdevila Cascante, Santiago; Jofre Roca, Lluís (2013-03)
      Article
      Accés restringit per política de l'editorial
      The performance of pattern reconfigurable antennas is evaluated with the purpose of deriving a figure-of-merit for pattern reconfigurability. A general formulation is provided for the average gain achieved by a ...
    • A frequency reconfigurable cell for beam-scanning reflectarrays 

      Rodrigo López, Daniel; Jofre Roca, Lluís; Perruisseau Carrier, Julien (Institute of Electrical and Electronics Engineers (IEEE), 2013)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Reflectarray antennas are excellent candidates for beam-scanning applications thanks to their low loss, light and quasi-planar structure and ease of electronic control. However, reflectarray antennas suffer from narrower ...
    • A near field spherical wave inverse synthetic aperture radar technique 

      Broquetas Ibars, Antoni; Jofre Roca, Lluís; Cardama Aznar, Ángel (Institute of Electrical and Electronics Engineers (IEEE), 1992)
      Text en actes de congrés
      Accés obert
      The authors present an imaging near-field spherical wave inverse synthetic aperture radar (SWISAR) algorithm based on a focusing operator of the scattered fields on the target surface. A spherical wave can be easily generated ...
    • A new class of antenna array with a reconfigurable element factor 

      Li, Zhouyuan; Rodrigo López, Daniel; Jofre Roca, Lluís; Cetiner, Bedri Artug (2013-04)
      Article
      Accés restringit per política de l'editorial
      A parasitic layer-based multifunctional reconfigurable antenna array (MRAA) formed by the linear combination of four (4 1) identical multifunctional reconfigurable antenna (MRA) elements is presented. Each MRA produces ...
    • A novel compact UHF wideband antenna for near field electrical characterization of Steel Fiber Reinforced Concrete 

      Roqueta Crusats, Gemma; Irteza, I; Romeu Robert, Jordi; Jofre Roca, Lluís (IEEE Computer Society Publications, 2009)
      Text en actes de congrés
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      A novel, electrically small, UHF (350 MHz–750 MHz)microstrip slot antenna is presented. The antenna is designed for the characterization of Steel Fiber Reinforced Concrete (SFRC) segments. The antenna consists on a three ...
    • A quad-band antenna for public safety applications 

      Mopidevi, Hema Swaroop; Damgaci, T; Rodrigo López, Daniel; Jofre Roca, Lluís; Cetiner, Bedri Artug (2014-01-01)
      Article
      Accés restringit per política de l'editorial
      The design, fabrication, and characterization of a frequency-reconfigurable antenna for the United States Public Safety (PS) wireless communication applications are presented. This antenna is quad-band operating in the PS ...
    • A reconfigurable antenna with beam steering and beamwidth variability for wireless communications 

      Towfiq, Asaduzzaman; Bahceci, Israfil; Blanch Boris, Sebastián; Romeu Robert, Jordi; Jofre Roca, Lluís; Cetiner, Bedri Artug (2018-07-12)
      Article
      Accés obert
      A reconfigurable antenna (RA) capable of steering its beam into the hemisphere corresponding to ¿ ¿ {-40°,0°,40°}, Ø ¿ {0°,45°,90°,-45°}, and of changing 3-dB beamwidth, where ¿3dB ¿ (40°,100°), Ø ¿ {45°,90°,-45°} for ...
    • A submillimeter wave parabolic reflector by additive manufacturing 

      Romeu Robert, Jordi; Aguasca Solé, Alberto; Blanch Boris, Sebastián; O'Callaghan Castellà, Juan Manuel; Jofre Roca, Lluís; Buitrago Ventura, Santiago (Institute of Electrical and Electronics Engineers (IEEE), 2018)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      The manufacturing of prototype of an offset parabolic reflector to operate at 120 GHz is presented. The paper describes the different metallization options to achieve a good performance.
    • Active microwave computed brain tomography: The response to a challenge 

      Broquetas Ibars, Antoni; Jofre Roca, Lluís (1991-02)
      Article
      Accés restringit per política de l'editorial
      The potential application of active microwave techniques to brain imaging is studied by numerical simulations and experimentally using a recently developed cylindrical microwave scanner. The potential advantages and ...
    • Active microwave imaging of inhomogeneous bodies 

      PICHOT DU MEZERAY, Christian; Jofre Roca, Lluís; Peronnet, Guy; Bolomey, Jean Charles (1986-04-01)
      Article
      Accés obert
      A numerical method and experimental technique for microwave imaging of inhomogenous bodies is presented. This method is based on the interpretation of the diffraction phenomena and leads to tomographic reconstruction of ...
    • Active microwave imaging: a cylindrical system for biomedical applications 

      Jofre Roca, Lluís; Broquetas Ibars, Antoni; Hawley, Mark (1988)
      Text en actes de congrés
      Accés obert
      The authors examine the use of active microwave tomography as an imaging technique which gives information on the dielectric properties of the body. They show that a cylindrical system is an efficient option to obtain ...
    • Active microwave sensing of highly contrasted dielectric bodies 

      Broquetas Ibars, Antoni; Mallorquí Franquet, Jordi Joan; Rius Casals, Juan Manuel; Jofre Roca, Lluís; Cardama Aznar, Ángel (1993-11)
      Article
      Accés restringit per política de l'editorial
      In this work the active tomographic imaging of biological bodies which exhibits a high dielectric contrast is studied. Two approaches based on the Born approximation are presented: a differential reconstruction method which ...
    • Adaptive beamwidth optimization under Doppler ICI and positioning errors at mmWave bands 

      Ballesteros Sánchez, Christian; Pfadler, Andreas; Montero Bayo, Luca; Romeu, Jordi; Jofre Roca, Lluís (Elsevier, 2022-04-01)
      Article
      Accés obert
      The growing trends towards massive antenna arrays with focusing capabilities has enabled the use of higher frequencies at the cost of more complex systems. In the particular case of vehicular communications, millimeter-wave ...
    • Admitancia de entrada de una guía rectangular rellena de dieléctrico 

      Jofre Roca, Lluís; Ferrando Bataller, Miquel; Cardama Aznar, Ángel (Unión Científica Internacional de Radio (URSI), 1983)
      Text en actes de congrés
      Accés obert
      A variational formulation, based in a plane wave angular decomposition, is developped for the admitance of a rectangular dielectric-filled waveguide, radiating in a half space.