Now showing items 1-20 of 28

  • A general approach for the calculation of intermodulation distortion in cavities with superconducting endplates 

    Mateu Mateu, Jordi; Collado Gómez, Juan Carlos; Menéndez Nadal, Óscar; O'Callaghan Castellà, Juan Manuel (AMER INST PHYSICS, 2003-01-31)
    Article
    Open Access
    We report on a general procedure to calculate intermodulation distortion in cavities with superconducting endplates that is applicable to the dielectric-loaded cavities currently used for measurement of surface resistance ...
  • A General Electromagnetic Simulation Tool to Predict the Microwave Nonlinear Response of Planar, Arbitrarily-Shaped HTS Structures 

    Parrón Granados, Josep; Collado Gómez, Juan Carlos; Mateu Mateu, Jordi; Rius Casals, Juan Manuel; Duffo Ubeda, Núria; O'Callaghan Castellà, Juan Manuel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2001-03-31)
    Article
    Open Access
    This work describes a simulation tool being developed at UPC to predict the microwave nonlinear behavior of planar superconducting structures with very few restrictions on the geometry of the planar layout. The software ...
  • Analysis and Simulation of Distributed Nonlinearities in Ferroelectrics and superconductors for Microwave Applications 

    Seron, David; Collado Gómez, Juan Carlos; Mateu Mateu, Jordi; O'Callaghan Castellà, Juan Manuel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2006-03-31)
    Article
    Open Access
    This paper gives closed-form equations for the intermodulation and third harmonic signals generated in a nonlinear transmission line with distributed quadratic nonlinearities in the conductor and dielectric. Although the ...
  • Analysis of dielectric-loaded cavities for characterization of the nonlinear properties of high temperature superconductors 

    Mateu Mateu, Jordi; Collado Gómez, Juan Carlos; Menéndez Nadal, Óscar; O'Callaghan Castellà, Juan Manuel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2003-06-30)
    Article
    Open Access
    This work describes and compares two alternative methods of analyzing dielectric-loaded cavities for measurement of intermodulation distortion in HTS films. One of them is based on assuming a specific type of HTS nonlinearities ...
  • Application of selective leaching in fabrication of thin film ybco devices 

    James, P. M.; O'Callaghan Castellà, Juan Manuel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1993-03-31)
    Article
    Open Access
    Ethylenediamine solutions have been shown to turn bulk YBCO into insulating materials. The effect of these solutions on thin YBCO films is studied. In both unpatterned and patterned films, a smooth decrease in critical ...
  • Coated conductor technology for the beamscreen chamber of future high energy circular colliders 

    Puig Molina, Teresa; Krkotic, Patrick; Romanov, Artur; O'Callaghan Castellà, Juan Manuel; Gutiérrez Royo, Joffre (2019-09-01)
    Article
    Restricted access - publisher's policy
    The surface resistance of state-of-the-art REBa2Cu3O7-x coated conductors has been measured at 8 GHz versus temperature and magnetic field. We show that the surface resistance of REBa2Cu3O7-x strongly depends on the ...
  • Comparison between nonlinear measurements in patterned and unpatterned thin films 

    Collado Gómez, Juan Carlos; Mateu Mateu, Jordi; O'Callaghan Castellà, Juan Manuel (IOP PUBLISHING LTD, 2004-07-31)
    Article
    Open Access
    This work compares two alternative methods of characterizing the nonlinearities in a 10 × 10 mm2 superconducting thin film. Both methods are based on measuring the intermodulation distortion in high temperature superconducting ...
  • Correction to "Nonlinear Analysis of Disk Resonators: Application to Material Characterization and Filter Design 

    Mateu Mateu, Jordi; Collado Gómez, Juan Carlos; O'Callaghan Castellà, Juan Manuel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2001-12-31)
    Article
    Open Access
    A procedure for the numerical prediction of the microwave nonlinear behavior (intermodulation products, degradation of quality factors, etc.) of TM010 disk resonators has been developed. The procedure is based on relating ...
  • Development of HPC multiphysics framework for HTS magnets in fusion 

    Lorenzo, José; Castillo-Reyes, Octavio; Granados García, Javier A.J.; Mantsinen, Mervi; Sáez, Xavier; Soba, Alejandro (Barcelona Supercomputing Center, 2019-05-07)
    Conference report
    Open Access
  • Experiments and model of intermodulation distortion in a rutile resonator with YBCO endplates 

    Mateu Mateu, Jordi; Collado Gómez, Juan Carlos; Menéndez Nadal, Óscar; O'Callaghan Castellà, Juan Manuel (KLUWER ACADEMIC/PLENUM PUBL, 2003-10-31)
    Article
    Open Access
    We have derived general equations to calculate intermodulation distortion in resonators with high temperature superconducting (HTS) films which are not restricted to a specific resonator shape and may be used whenever the ...
  • HTS nonlinearities in microwave disk resonators 

    Collado Gómez, Juan Carlos; Mateu Mateu, Jordi; Shaw, Timothy J.; O'Callaghan Castellà, Juan Manuel (ELSEVIER SCIENCE BV, 2002-08-31)
    Article
    Open Access
    This article describes a procedure for the calculation of the intermodulation behavior of the TM010 mode in high temperature superconducting (HTS) disk resonators from a description of the local HTS nonlinearities. Successful ...
  • Introduction to special issue of the proceedings of the 8th Symposium on High Temperature Superconductors in High Frequency Fields 

    Kokabi, Hamid; O'Callaghan Castellà, Juan Manuel (Springer New York LLC, 2006-11-30)
    Article
    Open Access
  • Magnetic field sensitivity of variable thickness microbridges in tbcco, bscco and ybco. 

    Davidson, B. A.; Redwing, R. D.; Nguyen, T. D.; O'Callaghan Castellà, Juan Manuel; Raissi, F.; Lee, J. V.; Bruke, J. P.; Hohenwarter, G. K. G.; Nordman, J. E.; Beyer, J. B. (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1994-12-31)
    Article
    Open Access
    We describe results of a study comparing the magnetic field sensitivities of variable thickness bridge (VTB) arrays fabricated in TBCCO, BSCCO, and YBCO thin films. Identical structures were patterned in a variety of films, ...
  • Mechanisms for conduction via low-frequency noise measurements of High-Tc Thin-film microbridges 

    Nguyen, T. D.; O'Callaghan Castellà, Juan Manuel; Davidson, B. A.; Redwing, R. D.; Hohenwarter, G. K. G.; Nordman, J. E.; Beyer, J. B. (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1995-01-31)
    Article
    Open Access
    We have investigated possible mechanisms for conduction in high-T/sub c/ thin-film microbridges biased into the voltage state via the low-frequency noise properties. Measurements on thinned YBCO microbridges indicate that ...
  • Microwave noise parameter measurements of a high temperature superconducting flux flow transistor 

    O'Callaghan Castellà, Juan Manuel; Martens, J. S.; Thompson, J. H.; Beyer, J. B.; Nordman, J. E. (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1991-02-28)
    Article
    Open Access
    The noise parameters of a high-temperature superconducting (HTS) flux flow transistor made of TlBaCaCuO operating at 77 K and 3-5 GHz were experimentally determined. It is assumed that the dominant noise mechanism of the ...
  • Miniaturization of superconducting filters using Hilbert fractal curves 

    Barra Bizinotto, Marilda; O'Callaghan Castellà, Juan Manuel; Collado Gómez, Juan Carlos; Mateu Mateu, Jordi (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-09-30)
    Article
    Open Access
    This work presents novel compact high-temperature superconductor microstrip resonators and filters based on the Hilbert space-filling fractal curve. Several Hilbert resonator configurations have been assessed by using a ...
  • Nonlinear Distortion in a 8-Pole Quasi-Elliptic Bandpass HTS Filter for CDMA System 

    Collado Gómez, Juan Carlos; Mateu Mateu, Jordi; Menéndez Nadal, Óscar; O'Callaghan Castellà, Juan Manuel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-06-30)
    Article
    Open Access
    High Temperature Superconductor materials are known to produce intermodulation and other nonlinear effects which may restrict their use in wireless communication systems. Quantifying this degradation is crucial in determining ...
  • Nonlinear Model of Coupled Superconducting Lines 

    Mateu Mateu, Jordi; Collado Gómez, Juan Carlos; O'Callaghan Castellà, Juan Manuel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-06-30)
    Article
    Open Access
    High Temperature Superconductor materials are known to produce intermodulation and other nonlinear effects. In planar structures, these nonlinearities depend on the field configuration on the strip, which in turn strongly ...
  • Nonlinear performance characterization in an eight-pole quasi-elliptic bandpass filter 

    Mateu Mateu, Jordi; Collado Gómez, Juan Carlos; Menéndez Nadal, Óscar; O'Callaghan Castellà, Juan Manuel (IOP PUBLISHING LTD, 2004-05-31)
    Article
    Open Access
    In this work we predict the nonlinear behaviour of an eight-pole quasi-elliptic bandpass high temperature superconducting (HTS) filter with an equivalent circuit extracted from intermodulation measurements performed at the ...
  • Nonlinear RF spurious in a cylindrical cavity with superconducting endplates 

    Mateu Mateu, Jordi; Collado Gómez, Juan Carlos; Shaw, Timothy J.; O'Callaghan Castellà, Juan Manuel (ELSEVIER SCIENCE BV, 2002-08-31)
    Article
    Open Access
    We have developed a method to calculate the distribution of fundamental and spurious fields in a metallic cylindrical cavity with superconducting endplates in which signals at two different frequencies are injected. The ...