Ara es mostren els items 14-33 de 124

    • Accurate determination of dielectric properties in small, high-permittivity dielectric cylinders 

      Tagdulang, Nikki; Krkotic, Patrick; Díez, A.; Pont Montaner, Montserrat; O'Callaghan Castellà, Juan Manuel (Institute of Electrical and Electronics Engineers (IEEE), 2022)
      Comunicació de congrés
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      We describe a method for performing cryogenic permittivity and loss tangent measurements of small (few mm), high-permittivity dielectric cylinders used in surface impedance measurement of superconductors. We combine the ...
    • Algorithm for resonator parameter extraction from symmetrical and asymmetrical transmission responses 

      Krkotic, Patrick; Gallardo Moix, Queralt; Tagdulang, Nikki; Pont Montaner, Montserrat; O'Callaghan Castellà, Juan Manuel (IEEE Microwave Theory and Techniques Society, 2021-08)
      Article
      Accés obert
      We describe an algorithm capable of extracting the unloaded quality factor and the resonant frequency of microwave resonators from vector S-parameters. Both symmetrical (Lorentzian) and asymmetrical (Fano) transmission ...
    • 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
      Accés obert
      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 and Simulation of the Effects of Distributed Nonlinearities in Microwave Superconducting Devices 

      Collado Gómez, Juan Carlos; Mateu Mateu, Jordi; O'Callaghan Castellà, Juan Manuel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-03-31)
      Article
      Accés obert
      This paper presents a comprehensive study of microwave nonlinearities in superconductors, with an emphasis on intermodulation distortion and third-harmonic generation. It contains the analysis of various resonant and ...
    • 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
      Accés obert
      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, Pm; O'Callaghan Castellà, Juan Manuel (1993-03)
      Article
      Accés obert
      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 ...
    • 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
      Accés obert
      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 ...
    • Banco automatizado para la medida de parámetros S, de ruido y características DC de transistores en oblea 

      Pradell i Cara, Lluís; Purroy, Francesc; Subirats, M.; Ballester, A.; Torres Torres, Francisco; O'Callaghan Castellà, Juan Manuel; Corbella Sanahuja, Ignasi (1994)
      Text en actes de congrés
      Accés obert
      The AMR Group has an automatized bench for the measurement of DC-characteristics, [S] parameters (45 MHz- 40 GHz) and noise parameters (2-26.5 GHz) of microwave on-wafer transistors. The hardware configuration is described, ...
    • Characterisation of copper and stainless steel surfaces treated with laser ablation surface engineering 

      Hannah, Adrian N.; Krkotic, Patrick; Valizadeh, Reza; Malyshev, Oleg; Mutch, J.; Whitehead, David J.; Pont, Montse; O'Callaghan Castellà, Juan Manuel; Dhanak, Vinod R. (2021-07)
      Article
      Accés obert
      In the past few years, it has been established that Laser Ablation Surface Engineering (LASE) is a very effective way of producing surfaces which have Secondary Electron Yields (SEY)¿<¿1. This can be achieved with a variety ...
    • 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
      Accés obert
      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 ...
    • Compact duplexer with miniaturized dual loop resonator 

      Collado Gómez, Juan Carlos; Pozo Vicente, Javier; Mateu Mateu, Jordi; O'Callaghan Castellà, Juan Manuel (Institute of Electrical and Electronics Engineers, 2005)
      Text en actes de congrés
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      This work presents a very compact duplexer based on novel miniaturized loaded-close-loop dual resonators. Two different dual resonators are used to establish the two bands, corresponding to the transmitter and the receiver ...
    • 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
      Accés obert
      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 ...
    • Comparison of lossy filters and predistorted filters using novel software 

      Padilla Díaz, Alberto; Mateu Mateu, Jordi; Collado Gómez, Juan Carlos; Ernst, Cristoph; Rius Casals, Juan Manuel; Tamayo Palau, José María; O'Callaghan Castellà, Juan Manuel (IEEE Microwave Theory and Techniques Society, 2010)
      Comunicació de congrés
      Accés obert
    • Comprehensive circuit model of auto-limiting superconductor devices and systems 

      Mateu Mateu, Jordi; Collado Gómez, Juan Carlos; Hueltes Escobar, Alberto; O'Callaghan Castellà, Juan Manuel; García Pastor, David; Perea Robles, Rafael; Joshi, N.; Lu, X.; Orloff, Nathan D.; Booth, James C. (Institute of Electrical and Electronics Engineers (IEEE), 2016)
      Comunicació de congrés
      Accés restringit per política de l'editorial
      This paper presents a phenomenological equivalent circuit to model the phenomenon occurring when a section of superconducting transmission line transits from a superconducting state to a normal state. This phenomenon allows ...
    • Comprehensive circuit model of autolimiting superconductor devices 

      Mateu Mateu, Jordi; Collado Gómez, Juan Carlos; Hueltes Escobar, Alberto; O'Callaghan Castellà, Juan Manuel; García Pastor, David; Perea Robles, Rafael; Joshi, N.; Lu, X.; Orloff, Nathan D.; Booth, James C. (2017-06-01)
      Article
      Accés obert
      This paper presents a phenomenological equivalent circuit to model the phenomenon occurring when a section of superconducting transmission line transits from a superconducting state to a normal state. This phenomenon allows ...
    • Contactless electrical resistance of 2D materials using a rutile resonator 

      Arcos Gutiérrez, David; Krkotic, Patrick; O'Callaghan Castellà, Juan Manuel; Pont, Montse; Ametller Congost, Lluís; Ferrer Anglada, Núria (2019-12-12)
      Article
      Accés obert
      Measuring the electrical surface resistance of 2D materials without contact can provide a method for obtaining their intrinsic characterisation. The aim of this paper is to show that a rutile dielectric resonator (RDR) can ...
    • 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
      Accés obert
      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 ...
    • Design and fabrication of coplanar YBCO structures on lithium niobate substrates 

      Rozan, Edouard; Collado Gómez, Juan Carlos; García, A.; O'Callaghan Castellà, Juan Manuel; Pous Andrés, Rafael; Fàbrega i Soler, Lluís; Rius Casals, Juan Manuel; Rubí, R.; Fontcuberta, Josep; Harackiewicz, F. (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1999-06-30)
      Article
      Accés obert
      YBa2Cu3O7-δ (YBCO) with low RF losses has been successfully deposited onto lithium niobate (LNO) to improve the performance of electrooptic Mach-Zender modulators. Epitaxial, c-axis oriented superconducting YBCO thin films ...
    • Design and fabrication of coplanar YBCO structures on lithium niobate substrates 

      Rozan, Edouard; Collado Gómez, Juan Carlos; Garcia, Alfredo; O'Callaghan Castellà, Juan Manuel; Pous Andrés, Rafael; Fàbrega Sanchez, Lourdes; Rius Casals, Juan Manuel; Rubí, R.; Fontcuberta, J.; Harackiewicz, F. (1999-06)
      Article
      Accés obert
      YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) with low RF losses has been successfully deposited onto lithium niobate (LNO) to improve the performance of electrooptic Mach-Zender modulators. Epitaxial, c-axis oriented ...
    • Determination of pumping and dynamic vacuum properties of conductive quaternary alloy of TiZrVAg non-evaporable getter 

      Valizadeh, Reza; Hannah, Adrian N.; Malyshev, Oleg; Hsiung, G.Y.; O'Callaghan Castellà, Juan Manuel; Pont, Montse; Tagdulang, Nikki (Joint Accelerator Conferences Website (JACoW), 2022)
      Text en actes de congrés
      Accés obert
      Non Evaporable Getter (NEG) coating has been employed extensively in the particle accelerator especial-ly where the vacuum conductance of the vessel is se-verely restricted and ultra-high vacuum condition is required. NEG ...