Ara es mostren els items 1-20 de 209

  • 100 GHz retina for THz tomographic imaging 

    Alonso, Maria; Guerra, C.; Nova, Enrique; Abril, Jordi; Romeu Robert, Jordi; Llombart, Nuria; Jofre Roca, Lluís (2011)
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    In a tomographic imaging system, the key is to collect a sufficient number of scattered field points to recover the currents in the inverse scattering problem. This can be accomplished by using a real array of multiplexed ...
  • 3D arrayed microwave tomographic system for medical imaging 

    Guardiola Garcia, Marta; Jofre Roca, Lluís; Gedda, F.; Capdevila Cascante, Santiago; Romeu Robert, Jordi; Blanch Boris, Sebastián (2010)
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    In this paper, a combined tomographic imaging system comprising the rotation of a multiplexed linear antenna array around the object under test is designed. With this system a cylindrical sampling is obtained, allowing to ...
  • 3D UWB magnitude-combined tomographic imaging for biomedical applications. Algorithm validation 

    Guardiola Garcia, Marta; Jofre Roca, Lluís; Capdevila Cascante, Santiago; Blanch Boris, Sebastián; Romeu Robert, Jordi (2011-06)
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    Biomedical microwave imaging is a topic of continuous research for its potential in different areas especially in breast cancer detection. In this paper, 3D UWB Magnitude-Combined tomographic algorithm is assessed for ...
  • 3D UWB tomography for medical imaging applications 

    Guardiola Garcia, Marta; Jofre Roca, Lluís; Romeu Robert, Jordi (2010)
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    In this paper, a novel 3D UWB tomographic algorithm has been presented for brain hemorrhagic stroke detection. While 2D reconstructions are unable to distinguish between features at different heights, 3D reconstructions ...
  • 60GHz channel characterization using a Scatterer Mapping Technique 

    Papió, Anna; Grau, Alfred; Balcells Ventura, Jordi; Romeu Robert, Jordi; Jofre Roca, Lluís; Flaviis, Franco de (2010)
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    In this paper, a Scatterer Mapping Technique based on a Multi-Frequency Bi-focusing operator with good imaging capabilities is used to characterize the 60GHz wireless channel in an office environment. The measurement data ...
  • 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)
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    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. ...
  • Active microwave computed brain tomography: The response to a challenge 

    Broquetas Ibars, Antoni; Jofre Roca, Lluís (1991-02)
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    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: a cylindrical system for biomedical applications 

    Jofre Roca, Lluís; Broquetas Ibars, Antoni; Hawley, Mark (1988)
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    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 imaging of inhomogeneous bodies 

    PICHOT DU MEZERAY, Christian; Jofre Roca, Lluís; Peronnet, Guy; Bolomey, Jean Charles (1986-04-01)
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    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 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)
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    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 ...
  • A cylindrical array for fast microwave tomography 

    de los Reyes, Elías; Jofre Roca, Lluís; Broquetas Ibars, Antoni; Elias Fusté, Antonio; Cardama Aznar, Ángel (Unión Científica Internacional de Radio (URSI), 1987)
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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, Antonio; Romeu Robert, Jordi; Baquero, M; Rius Casals, Juan Manuel (Institute of Electrical and Electronics Engineers (IEEE), 1986)
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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 ...
  • 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)
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    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.
  • A figure-of-merit for pattern reconfigurable antennas 

    Rodrigo López, Daniel; Romeu Robert, Jordi; Capdevila Cascante, Santiago; Jofre Roca, Lluís (2013-03)
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    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 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)
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    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 frequency reconfigurable cell for beam-scanning reflectarrays 

    Rodrigo López, Daniel; Jofre Roca, Lluís; Perruisseau Carrier, Julien (Institute of Electrical and Electronics Engineers (IEEE), 2013)
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    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 ...
  • Agrupación plana alimentada por linea de sustrato suspendido 

    Torrents Dolz, Josep M.; Romeu Robert, Jordi; Jofre Roca, Lluís (1989)
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    The purpose of this design is a new type of planar antenna with hi gh-efficency and large-bandwidth requirements of TVRO. A low loss suspended substrate line (SSL ) has been developed and optimisated for feed network.
  • Algoritmo iterativo de propagación espectral para el cálculo de RCS en cavidades conductoras 

    Rius Casals, Juan Manuel; Cardama Aznar, Ángel; Jofre Roca, Lluís (1992)
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    One of the most difficult problems in the RCS prediction of a complex target is the analysis of the cavities existing at the air inlets and outlets of engines. The geometrical complexity of these structures makes difficult ...
  • Algoritmos de tomografía de microondas para objetos de alto contraste 

    Broquetas Ibars, Antoni; Jofre Roca, Lluís (Universidad Politécnica de Madrid (UPM), 1988)
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    Conventional first order algorithms used in microwave tomography often fail to reconstruct biological bodies due to their high contrast in permittivity. The paper presents several methods to improve the applicability of ...
  • Algoritmos de tomografía de microondas para objetos de alto contrastre 

    Broquetas Ibars, Antoni; Ferrando Bataller, Miquel; Jofre Roca, Lluís (Universidad Politécnica de Madrid (UPM), 1988)
    Text en actes de congrés
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    Conventional first order algorithms used in microwave tomography often fail to reconstruct biological bodies due to their high contrast in permittivity. The paper presents several methods to improve the applicability of ...