Ara es mostren els items 1-20 de 53

  • Accelerated direct solution of the method-of-moments linear system 

    Heldring, Alexander; Tamayo, J.M.; Úbeda Farré, Eduard; Rius Casals, Juan Manuel (2012-08)
    Article
    Accés restringit per política de l'editorial
    This paper addresses the direct (noniterative) solution of the method-of-moments (MoM) linear system, accelerated through block-wise compression of the MoM impedance matrix. Efficient matrix block compression is achieved ...
  • Accelerated direct solution of the MoM linear system using block compression and nested factorization 

    Heldring, Alexander; Rius Casals, Juan Manuel (IEEE, 2011)
    Text en actes de congrés
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    A comparison is presented between different algorithms for direct (non-iterative) accelerated solution of the Method of Moments. The alternatives are common block LU factorization and Compressed Block Decomposition (CBD), ...
  • Accelerated direct solution of the MoM-VIE for dielectric scatterers 

    Heldring, Alexander; Tamayo Palau, José María; Rius Casals, Juan Manuel; Úbeda Farré, Eduard (2011)
    Text en actes de congrés
    Accés obert
    The Multiscale Compressed Block Decomposition algorithm (MS-CBD), a direct (non-iterative) linear solver, is applied to accelerate the solution of the MoM-VIE formulation for dielectric scatterers. Numerical solutions are ...
  • Accurate numerical modeling of the TARA reflector system 

    Heldring, Alexander; Rius Casals, Juan Manuel; Ligthart, Leo P.; Cardama Aznar, Ángel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2004-07-31)
    Article
    Accés obert
    The radiation pattern of the large parabolic reflectors of the Transportable Atmospheric RAdar system (TARA), developed at Delft University of Technology, has been accurately simulated. The electric field integral ...
  • Adapted ACA algorithm with improved efficiency and compression rate 

    Heldring, Alexander; Úbeda Farré, Eduard; Rius Casals, Juan Manuel (2015)
    Text en actes de congrés
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    This contribution proposes an adapted version of the popular Adaptive Cross Approximation algorithm for block wise compression of Method of Moments impedance matrices. The estimation of the matrix block ...
  • A microwave invisibility cloak: the design, simulation, and measurement of a simple and effective frequency-selective surface-based mantle cloak 

    Yuste, Pedro; Rius Casals, Juan Manuel; Romeu Robert, Jordi; Blanch Boris, Sebastián; Heldring, Alexander; Úbeda Farré, Eduard (2018-06-26)
    Article
    Accés obert
    In recent years, there has been a growing interest in developing invisibility cloaks that can conceal an object. These techniques are often based either on coating a dielectric or conducting object with a homogeneous ...
  • Analysis of microstrip antennas by multilevel matrix decomposition algorithm 

    Parrón Granados, Josep; Rius Casals, Juan Manuel; Heldring, Alexander; Úbeda Farré, Eduard; Mosig, Juan R (ESA, 1999)
    Text en actes de congrés
    Accés obert
    Integral equation methods (IE) are widely used in conjunction with Method of Moments (MoM) discretization for the numerical analysis of microstrip antennas. However, their application to large antenna arrays is difficult ...
  • Analysis of reflector and horn antennas using multilevel fast multipole algorithm 

    Heldring, Alexander; Rius Casals, Juan Manuel; Parrón Granados, Josep; Cardama Aznar, Ángel; Ligthart, L P (CIMNE, 2000)
    Text en actes de congrés
    Accés obert
    The MultiLevel Fast Multipole Algorithm (MLFMA) has been implemented in a Method of Moments code for arbitrarily shaped metal surfaces discretized in Rao, Wilton and Glisson (RWG) basisfunctions. The accuracy of the ...
  • Application of Multilevel Adaptive Cross Approximation (MLACA) to electromagnetic scattering and radiation problems 

    Tamayo Palau, José María; Heldring, Alexander; Rius Casals, Juan Manuel (2009-09-14)
    Text en actes de congrés
    Accés obert
  • A recursive acceleration technique for static potential Green's functions of a rectangular cavity combining image and modal series 

    Tamayo Palau, José María; López-Peña, Sergio; Mattes, Michael; Heldring, Alexander; Rius Casals, Juan Manuel; Mosig, Juan Ramón (2011-03)
    Article
    Accés restringit per política de l'editorial
    A hybrid acceleration algorithm for the computation of the static potential Green’s functions of a rectangular cavity is proposed. Similarly to Ewald’s method, it combines the series expansions in terms of images and modes. ...
  • A simple and effective microwave invisibility cloak based on frequency selective surfaces 

    Yuste, Pedro; Rius Casals, Juan Manuel; Romeu Robert, Jordi; Blanch Boris, Sebastián; Heldring, Alexander; Úbeda Farré, Eduard (Institute of Electrical and Electronics Engineers (IEEE), 2017)
    Comunicació de congrés
    Accés obert
    This paper presents the design, simulation, manufacturing and testing of a simple invisibility cloak based on a frequency selective surface (FSS). The work is focused on cloaking an electrically thin dielectric cylinder ...
  • Compression of the MoM matrix using macrobasis functions with a full-controlable accuracy 

    Tamayo Palau, José María; Heldring, Alexander; Rius Casals, Juan Manuel (EurAPP, 2009)
    Text en actes de congrés
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    A new accuracy-controlable method for compressing the MoM impedance matrix of an electromagnetic problem based on a basis change plus a truncation with a threshold is presented here. The idea is to switch to singular basis ...
  • Creació de recursos en línea per a l’autoaprenentage, foment de l’esperit crític i emprenedor i formació d’un comité d’avaluació externa en el màster MERIT 

    Pradell i Cara, Lluís; Cabrera-Bean, Margarita; Canal Bienzobas, Fernando; Cardama Aznar, Ángel; Gasull Llampallas, Antoni; González Arbesú, José María; Giró Nieto, Xavier; Heldring, Alexander; Herranz Luis, Jaime; Jofre Roca, Lluís; Mallorquí Franquet, Jordi Joan; Nadeu Camprubí, Climent; Olmos Bonafé, Juan José; Romeu Robert, Jordi; Rius Casals, Juan Manuel; Torres Torres, Francisco; Úbeda Farré, Eduard; Coderch Collell, Marcel; Kerans, Mary Ellen; Ros Giralt, Jordi; García, Antonio; González Font, Blanca; Guardiola Garcia, Marta; Hernández, Antoni; Melgarejo, Natali; Mestres, Albert (2009-02-12T10:25:51Z)
    Comunicació de congrés / Text en actes de congrés
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    El projecte es desenvolupa en el marc de la titulació oficial de màster MERIT del Departament de Teoria del Senyal i Comunicacions. El màster, orientat a la recerca i integrat dins del programa Erasmus Mundus, presenta ...
  • Discretization of the EFIE in Method of Moments without continuity of the normal current component across edges 

    Úbeda Farré, Eduard; Rius Casals, Juan Manuel; Heldring, Alexander (Institute of Electrical and Electronics Engineers (IEEE), 2013)
    Text en actes de congrés
    Accés restringit per política de l'editorial
    The discretization in Method of Moments (MoM) of the Electric-Field Integral Equation (EFIE) is traditionally carried out by preserving the continuity of the normal component in the expansion of the current across the ...
  • Edge diffraction computation using GRECO 

    Rius Casals, Juan Manuel; Carbo, Alex; Úbeda Farré, Eduard; Heldring, Alexander (Institute of Electrical and Electronics Engineers (IEEE), 2016)
    Text en actes de congrés
    Accés restringit per política de l'editorial
    This paper addresses two graphical processing approaches for computation of edge scattering with Physical Theory of Diffraction (PTD) high-frequency approximation. One is based on processing only a bitmap containing an ...
  • Efficient analysis of homogeneous dielectric and plasmonic media with integral equation MEI (IE-MEI) 

    Rius Casals, Juan Manuel; Planes Conangla, Gerard; Úbeda Farré, Eduard; Heldring, Alexander (Institute of Electrical and Electronics Engineers (IEEE), 2015)
    Comunicació de congrés
    Accés restringit per política de l'editorial
    This paper revisits the IE-MEI method and proposes a new formulation for high-loss dielectric piecewise-homogeneous media. The aim of this work is to assess if the fast attenuation of fields in highly lossy media helps in ...
  • Efficient computation of the effect of wire ends in thin wire analysis 

    Heldring, Alexander; Úbeda Farré, Eduard; Rius Casals, Juan Manuel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2006-10-31)
    Article
    Accés obert
    Computationally efficient algorithms are presented for the computation of the effect of flat wire ends (end caps) in the common thin wire model. A uniform charge distribution over the surface of the end cap is assumed, and ...
  • Error bound of the multilevel adaptive cross approximation (MLACA) 

    Chen, Xinlei; Gu, Changqing; Heldring, Alexander; Li, Zhuo; Cao, Qunsheng (2016-01)
    Article
    Accés obert
    An error bound of the multilevel adaptive cross approximation (MLACA 1, which is a multilevel version of the adaptive cross approximation-singular value decomposition (ACA-SVD), is rigorously derived. For compressing an ...
  • Fast direct solution of method of moments linear system 

    Heldring, Alexander; Rius Casals, Juan Manuel; Tamayo Palau, José María; Parrón Granados, Josep; Úbeda Farré, Eduard (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2007-11)
    Article
    Accés obert
    A novel algorithm, the compressed block decomposition (CBD), is presented for highly accelerated direct (non iterative) method of moments (MoM) solution of electromagnetic scattering and radiation problems. The algorithm ...
  • Fast direct solution of the combined field integral equation 

    Heldring, Alexander; Tamayo Palau, José María; Rius Casals, Juan Manuel (2010)
    Text en actes de congrés
    Accés obert
    The Method of Moments for electromagnetic scattering and radiation problems is often used in conjunction with the EFIE because the EFIE allows the analysis of open surfaces. For electrically large closed surfaces, the ...