Now showing items 21-40 of 210

  • Algoritmos para el cálculo de los campos lejanos radiados por antenas, a partir de medidas en campo próximo 

    Jofre Roca, Lluís; Cardama Aznar, Ángel (1980)
    Conference report
    Open Access
    We present the principles of operation of near field antenna ranges and general expressions for the calculation of the far field, from measurements on plane surfaces, focusing on the limitations of the different aproaches. ...
  • Análisis de antenas parabólicas 

    Jofre Roca, Lluís; Cardama Aznar, Ángel (1981)
    Conference report
    Open Access
    This paper describes a set of procedures for computing secondary patterns of parabolic-reflector antennas. Once the primary feed radiation pattern is defined, aperture-plane fields are computed for a grid of points using ...
  • Análisis de Errores de Medida en Campo Próximo Cilíndrico 

    Soneira Ferrando, M. José; Clavera, Jordi; Jofre Roca, Lluís; Romeu Robert, Jordi; de los Reyes, Elías (Universidad Politécnica de Madrid (UPM), 1988)
    Conference report
    Open Access
    A prograrn to compute near and far fields generated by a planar array has been developed . Sirnulations on the effect of antenna and rnesurernent errors in the cylindrical near-far field transforrnations algorithrns have ...
  • Análisis de guías parcialmente rellenas de dieléctrico mediante el método de los elementos finitos 

    Ferrando Bataller, Miquel; Cruellas Ibarz, Juan Carlos; Cardama Aznar, Ángel; Jofre Roca, Lluís (Unión Científica Internacional de Radio (URSI), 1983)
    Conference report
    Open Access
    The finite element's method is aplied to the study of inhomogenous waveguides of arbitrary cross-section. The fields in the guide are - expanded in a series of bidimensional functions, obtaining a variational expression ...
  • Análisis de la difracción de cuerpos metálicos mediante el método incremental 

    Broquetas Ibars, Antoni; Romeu Robert, Jordi; Jofre Roca, Lluís (1989)
    Conference report
    Open Access
    An incremental method for diffraction analysis of metalic bodies of arbitrary shape is presented. The algorithm has been evaluated for metalic cylinders and for tridimensional bodies using a scalar approximation of the field.
  • Análisis y medida en campo próximo de antenas parabólicas 

    Jofre Roca, Lluís; Ferrando Bataller, Miquel (Consejo Superior de Investigaciones Científicas (CSIC), 1986)
    Conference report
    Open Access
    A complet process of design and measurement of parabolic antennas, is presented. We have implemented a set of programs in order to design and analyze the different geometries of parabolic reflectors. The measurements are ...
  • Analysis of the electromagnetic signature of reinforced concrete structures for nondestructive evaluation of corrosion damage 

    Roqueta Crusats, Gemma; Jofre Roca, Lluís; Feng, M.Q. (2012-04)
    Article
    Restricted access - publisher's policy
    This paper presents a nondestructive corrosion damage detection method for reinforced concrete structures based on the analysis of the electromagnetic signature of the steel rebar corrosion. The signature of the corrosion ...
  • An approximate expression to estimate signal-to-noise improvement in cylindrical near-field measurements 

    Romeu Robert, Jordi; Jofre Roca, Lluís; Cardama Aznar, Ángel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1994-07-01)
    Article
    Open Access
    A very simple approximate expression for the process gain (PG) for the cylindrical case is derived. The different approximations and assumptions required to obtain this expression are shown. This expression might be useful ...
  • 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)
    Conference report
    Open Access
    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
    Restricted access - publisher's policy
    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)
    Conference report
    Open Access
    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 ...
  • Antenas 

    Cardama Aznar, Ángel; Jofre Roca, Lluís; Rius Casals, Juan Manuel; Romeu Robert, Jordi; Blanch Boris, Sebastián; Ferrando Bataller, Miguel (Edicions UPC, 2002)
    Book
    Restricted access to UB, UAB, UPC, UPF, UdG, UdL, URV, UOC, BC, UVic, UJI, URL, UIC users
    En este libro se presentan los métodos fundamentales de análisis de antenas con un nivel de detalle que permite comprender sus principios de funcionamiento y conocer los parámetros de diseño que son de interés práctico. ...
  • Antenas para radio y TV. Principios de funcionamiento y características técnicas 

    Cardama Aznar, Ángel; Jofre Roca, Lluís (1980-09)
    Article
    Restricted access - publisher's policy
    Existe una gran variedad de antenas utilizadas satisfactoriamente como transmisoras y receptoras y aunque en cada banda de frecuencias existe una gran especialización de los tipos empleados, todas ellas operan sobre ...
  • Antenna input impedance measurement using multi-load MST 

    Romeu Robert, Jordi; Capdevila Cascante, Santiago; Bolomey, Jean Charles; Jofre Roca, Lluís (Institute of Electrical and Electronics Engineers (IEEE), 2013)
    Conference report
    Restricted access - publisher's policy
    This paper presents the practical use of modulated scatterer technique (MST) for the measurement of the antenna input impedance using a multi-load automatic switching device, and it also includes the analysis of the ...
  • Antenna reconfigurability based on a novel parasitic pixel layer 

    Rodrigo López, Daniel; Damgaci, Yasin; Unlu, M.; Cetiner, Bedri Artug; Romeu Robert, Jordi; Jofre Roca, Lluís (2011)
    Conference report
    Restricted access - publisher's policy
    A novel reconfiguration method based in the use of pixel surfaces as parasitic elements is presented. This concept can be used to provide reconfigurability to a wide variety of non-reconfigurable antennas without requiring ...
  • Aprendizaje y asistencia virtual en red 

    Fuentes Fort, Maria; González Bermúdez, Meritxell; Guardiola Garcia, Marta; Jofre Roca, Lluís; Romeu Robert, Jordi; Vallverdú Bayés, Sisco (2011-01-20)
    External research report
    Open Access
    Favorecer el uso de las Tecnologías de Información y la Comunicación (TIC) en entornos educativos puede abarcar varios aspectos del proceso de aprendizaje. La incorporación de TICs en las aulas contribuye, por un lado a ...
  • Aprendizaje y asistencia virtual en red /Aprenentatge i assistència virtual en xarxa 

    Jofre Roca, Lluís; Romeu Robert, Jordi; Vallverdú Bayés, Sisco; Fuentes Fort, Maria; Guardiola Garcia, Marta (Universitat Politècnica de Catalunya. Càtedra Telefónica-UPC, 2011-01)
    Book
    Open Access
  • Aprendizaje y asistencia virtual en red : la prueba Piloto : Cátedra Telefófica UPC : Análisis de le evolución y tendencias futuras de la sociedad de la información 

    Fuentes Fort, Maria; González Bermúdez, Meritxell; Guardiola Garcia, Marta; Jofre Roca, Lluís; Romeu Robert, Jordi; Vallverdú Bayés, Sisco (2011-07-29)
    External research report
    Open Access
    Hemos llevado a cabo una prueba piloto, demostradora del uso de las tecnologías del lenguaje y el habla aplicadas al aprendizaje de inglés. En general, se espera que la actividad acerque al alumno el máximo posible a la ...
  • 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
    Restricted access - publisher's policy
    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
    Open Access
    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 ...