Now showing items 4-21 of 21

  • Hybrid sparse linear array synthesis applied to phased antenna arrays 

    Yepes, Leonardo Fabio; Covarrubias, David; Alonso, Miguel A.; Ferrús Ferré, Ramón Antonio (2014-01-16)
    Article
    Restricted access - publisher's policy
    In this letter, a new hybrid technique to synthesize sparse linear arrays is proposed. This technique is based on the combination of two methods. As a first method, a deterministic synthesis algorithm is used to resolve ...
  • Iterative method of moments solution of problems involving electrically large and concave geometries 

    Heldring, Alexander; Rius Casals, Juan Manuel; Úbeda Farré, Eduard (Institute of Electrical and Electronics Engineers (IEEE), 2013)
    Conference report
    Restricted access - publisher's policy
    This paper presents a study of the scaling with frequency (computational complexity) of preconditioned iterative solution, using the Multilevel Fast Multipole Method, of a class of radiation and scattering problems that ...
  • Maximum likelihood estimation of position in GNSS 

    Closas Gómez, Pau; Fernández Prades, Carlos; Fernández Rubio, Juan Antonio (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2007-05)
    Article
    Open Access
    In this letter, we obtain the Maximum Likelihood Estimator of position in the framework of Global Navigation Satellite Systems. This theoretical result is the basis of a completely different approach to the positioning ...
  • Method of moments enhancement technique for the analysis of Sierpinski pre-fractal antennas 

    Parrón Granados, Josep; Romeu Robert, Jordi; Rius Casals, Juan Manuel; Mosig, Juan R. (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2003-08-31)
    Article
    Open Access
    The numerical analysis of highly iterated Sierpinski microstrip patch antennas by method of moments (MoM) involves many tiny subdomain basis functions, resulting in a very large number of unknowns. The Sierpinski ...
  • Mètodes iteratius per a la resolució d'equacions no lineals 

    Fernández Sánchez, Marc (Universitat Politècnica de Catalunya, 2012-06-28)
    Master thesis (pre-Bologna period)
    Open Access
    El projecte consisteix en un estudi tant teòric com pràctic d'alguns dels mètodes iteratius sense memòria, emprats per la resolució d'equacions no lineals. Es plantegen i analitzen els cinc mètodes següents: Newton, Txebixev, ...
  • Un método simplificado de Newton para calcular la raíz cuadrada de una matriz real simétrica definida positiva 

    Mendoza Mexía, Alfredo; Gómez Aldama, Óscar Rubén (Universitat Politècnica de Catalunya, 2010)
    Article
    Open Access
  • ML estimator and hybrid beamformer for multipath and interference mitigation in GNSS receivers 

    Seco Granados, Gonzalo; Fernández Rubio, Juan Antonio; Fernández Prades, Carlos (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-05-31)
    Article
    Open Access
    This paper addresses the estimation of the code-phase(pseudorange) and the carrier-phase of the direct signal received from a direct-sequence spread-spectrum satellite transmitter. The signal is received by an antenna ...
  • Multiuser resource allocation optimization using bandwidth-power product in cognitive radio networks 

    Tachwali, Yahia; Lo, B.F.; Akyildiz, Ian; Agustí Comes, Ramon (2013-03)
    Article
    Restricted access - publisher's policy
    In this paper, the problem of resource allocation optimization is studied for a single-cell multiuser cognitive radio network in the presence of primary user networks. The spectral access of the cognitive radio network is ...
  • Nonlinear actuation model for lateral electrostatically-actuated DC-contact RF MEMS series switches. 

    Lázaro Guillén, Antoni; Girbau Sala, David; Pradell i Cara, Lluís; Nebot Serra, Àlvar (JOHN WILEY & SONS INC, 2007-06-01)
    Article
    Open Access
    In this work, a nonlinear model to predict actuation characteristics in lateral electrostatically-actuated DC-contact MEMS switches is proposed. In this case a parallel-plate approximation cannot be applied. The model ...
  • Practical algorithms for a family of waterfilling solutions 

    Pérez Palomar, Daniel; Rodríguez Fonollosa, Javier (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-02-28)
    Article
    Open Access
    Many engineering problems that can be formulated as constrained optimization problems result in solutions given by a waterfilling structure; the classical example is the capacity-achieving solution for a frequency-selective ...
  • Preconditioning techniques in the analysis of finite metamaterial slabs 

    Úbeda Farré, Eduard; Rius Casals, Juan Manuel; Romeu Robert, Jordi (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2006-01-31)
    Article
    Open Access
    In the method of moments (MoM) electric field integral equation (EFIE) analysis of slabs of metamaterials, we show that a left-preconditioning scheme by blocks gathering interactions between basis functions belonging to ...
  • Quantitative images of large biological bodies in microwave tomography by using numerical and real data 

    Mallorquí Franquet, Jordi Joan; Joachimowicz, N.; Broquetas Ibars, Antoni; Bolomey, J. C. (Jean-Charles) (IEE-INST ELEC ENG, 1996-11-01)
    Article
    Open Access
    A new inverse microwave imaging algorithm is presented which has the ability to obtain quantitative dielectric maps of large biological bodies. By using a priori information, obtained with a first order algorithm, the final ...
  • Second-order parameter estimation 

    Villares Piera, Nemesio J.; Vázquez Grau, Gregorio (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-07-31)
    Article
    Open Access
    This work provides a general framework for the design of second-order blind estimators without adopting any approximation about the observation statistics or the a priori distribution of the parameters. The proposed ...
  • Self-similar prefractal frequency selective surfaces for multiband and dual-polarized applications 

    Gianvittorio, John P.; Romeu Robert, Jordi; Blanch Boris, Sebastián; Rahmat-Samii, Yahya (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2003-01-31)
    Article
    Open Access
    Frequency-selective surfaces (FSS) that have been designed using the iterative techniques of fractals have been fabricated and measured. Fractals contain many scales of the starting geometry, each of which acts as a ...
  • Spectral iterative algorithm for RCS computation in electrically large or intermediate perfectly conducting cavities 

    Rius Casals, Juan Manuel; Lozano Solsona, Angel; Cardama Aznar, Ángel; Jofre Roca, Lluís (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1994-06-01)
    Article
    Open Access
    A novel algorithm designed to compute efficiently and accurately the high-frequency electromagnetic scattering from open-ended waveguide cavities is presented. The cavity is converted into a stepped-waveguide model so that ...
  • SSFB: a highly-efficient and scalable simulation reduction technique for SRAM yield analysis 

    Rana, Manish; Canal Corretger, Ramon (European Interactive Digital Advertising Alliance (EDAA), 2014)
    Conference report
    Restricted access - publisher's policy
    Estimating extremely low SRAM failure-probabilities by conventional Monte Carlo (MC) approach requires hundreds-of-thousands simulations making it an impractical approach. To alleviate this problem, failure-probability ...
  • The Koch monopole: a small fractal antenna 

    Puente Baliarda, Carles; Romeu Robert, Jordi; Cardama Aznar, Ángel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2000-11)
    Article
    Open Access
    Fractal objects have some unique geometrical properties. One of them is the possibility to enclose in a finite area an infinitely long curve. The resulting curve is highly convoluted being nowhere differentiable. One such ...
  • Unveiling internal evolution of parallel application computation phases 

    Servat Gelabert, Harald; Llort Sanchez, German Matías; Giménez Lucas, Judit; Huck, Kevin A.; Labarta Mancho, Jesús José (Institute of Electrical and Electronics Engineers (IEEE), 2011)
    Conference report
    Restricted access - publisher's policy
    As access to supercomputing resources is becoming more and more commonplace, performance analysis tools are gaining importance in order to decrease the gap between the application performance and the supercomputers' peak ...