Josephson Parametric Amplifiers: Low Noise at 9GHz

  • H. K. Olsson
  • T. Claeson
Conference paper


The performance of a thin film, (Nb/PbBi), resistive rf-SQUID as a parametric amplifier was investigated at 9 GHz. It was matched to a 50Ω coaxial cable via a low impedance (ZL) microstrip transformer. This allowed relatively high Josephson currents, .Io, to be used. Stable Josephson oscillations were achieved for βLQ=2eIOZL/hf<l.1-1.8. Best amplifier performance was obtained in the 3 and 4 photon, externally pumped modes. Both these two types gave signal gains more than 10 dB and negligible noise power contributions. A hot/cold measurement at a bath temperature of 1.2K gave Gdsb = 13 dB and Tdsb=3±4K over a bandwidth of 310 MHz for the 4 photon amplifier (dsb = double side band). Internally pumped amplifiers were noisier, e.g., a 4 photon one gave single side band noise of the order of 50 K.


Pump Power Critical Current Tunnel Junction Noise Temperature Shunt Resistor 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    N. Calander, T. Claeson, and S. Rudner, Appl. Phys. Lett. 39 ,650 (1981)ADSCrossRefGoogle Scholar
  2. 1a.
    N. Calander, T. Claeson, and S. Rudner J. Appl. Phys. 53 ,5093 (1982) .ADSCrossRefGoogle Scholar
  3. 2.
    A.D. Smith, R.D. Sandell, J.F. Burch, and A.H. Silver, IEEE Trans. Magn. MAG-21 ,1022 (1987) .ADSGoogle Scholar
  4. 3.
    L.S. Kuzmin, K.K. Likharev, V.V. Migulin, E.A. Polunin, and N.A. Simonov, in SQUID 85 ( H.D.Hahlbohm and H.Lübbig), Walter de Gruyter, Berlin 1985, p. 1029.Google Scholar
  5. 4.
    H.K. Olsson and T. Claeson, Jpn. J. Appl. Phys. 26 ,1547 (1987).CrossRefGoogle Scholar
  6. 5.
    H.K. Olsson, Electron Lett. 23 ,1152 (1987).CrossRefGoogle Scholar
  7. 6.
    P. Russer, Archiv der Elektrischen Übertragung 23 ,417 (1979).Google Scholar
  8. 7.
    H.K. Olsson and T. Claeson, J. Appl. Phys, in print, H.K. Olsson, PhD thesis, Chalmers Univ. of Techn., Göteborg, 1988.Google Scholar
  9. 8.
    D. Rogovin and D.J. Scalapino, Ann. Phys. 86 ,1 (1974).ADSCrossRefGoogle Scholar
  10. 9.
    K.K. Likharev, Dynamics of Josephson Junctions and Circuits ,Gordon and Breach Sei. Publ., N.Y. 1986, p. 392.Google Scholar

Copyright information

© Springer Japan 1989

Authors and Affiliations

  • H. K. Olsson
    • 1
  • T. Claeson
    • 1
  1. 1.Physics DepartmentChalmers University of TechnologyGöteborgSweden

Personalised recommendations