Precision measurement method for cryogenic amplifier noise temperatures below 5 K

We report precision measurements of the effective input noise temperature of a cryogenic (liquid-helium temperature) monolithic-microwave integrated-circuit amplifier at the amplifier reference planes within the cryostat. A method is given for characterizing and removing the effect of the transmission lines between the amplifier reference planes and the input and output connectors of the cryostat. In conjunction with careful noise measurements, this method enables us to measure amplifier noise temperatures below 5 K with an uncertainty of 0.3 K. The particular amplifier that was measured exhibits a noise temperature below 5.5 K from 1 to 11 GHz, attaining a minimum value of 2.3 K/spl plusmn/0.3 K at 7 GHz. This corresponds to a noise figure of 0.034 dB/spl plusmn/0.004 dB. The measured amplifier gain is between 33.4 dB/spl plusmn/0.3 dB and 35.8 dB/spl plusmn/0.3 dB over the 1-12-GHz range.

[1]  C. Caves.  Quantum limits on noise in linear amplifiers , 1982 .

[2]  Herbert Zirath,et al.  On the performance of low-noise low-DC-power-consumption cryogenic amplifiers , 2002 .

[3]  Marc J. Feldman,et al.  Quantum detection at millimeter wavelengths , 1985 .

[4]  E. Gerecht,et al.  A terahertz focal plane array using HEB superconducting mixers and MMIC IF amplifiers , 2005, IEEE Microwave and Wireless Components Letters.

[5]  S. Standard.  GUIDE TO THE EXPRESSION OF UNCERTAINTY IN MEASUREMENT , 2006 .

[6]  H. Callen,et al.  Irreversibility and Generalized Noise , 1951 .

[7]  Juan Daniel Gallego,et al.  Accuracy of Noise Temperature Measurement of Cryogenic Amplifiers , 1992 .

[8]  Herbert Zirath,et al.  Cryogenic wide-band ultra-low-noise IF amplifiers operating at ultra-low DC power , 2003 .

[9]  Juan D. Gallego-Puyol,et al.  Wideband ultra-low noise cryogenic InP IF amplifiers for the Herschel mission radiometers , 2003, SPIE Astronomical Telescopes + Instrumentation.

[10]  M. Pospieszalski,et al.  Extremely low-noise amplification with cryogenic FETs and HFETs: 1970-2004 , 2005, IEEE Microwave Magazine.

[11]  A. Kerr.  Suggestions for revised definitions of noise quantities, including quantum effects , 1999 .

[12]  E. Gerecht,et al.  NbN hot electron bolometric mixers-a new technology for low noise THz receivers , 1999, 1999 IEEE MTT-S International Microwave Symposium Digest (Cat. No.99CH36282).

[13]  M. W. Pospieszalski,et al.  Microwave instrumentation for radio astronomy , 2002 .