Low-noise S-band DC SQUID based amplifier

Author

Prokopenko, Georgy V. ; Shitov, Sergey V. ; Balashov, Dmitry V. ; Dmitriev, Pavel N. ; Koshelets, Valery P. ; Mygind, Jesper

Author_Institution

Inst. of Radio Eng. & Electron., Acad. of Sci., Moscow, Russia

Volume

11

Issue

1

fYear

2001

fDate

3/1/2001 12:00:00 AM

Firstpage

1239

Lastpage

1242

Abstract

A low-noise rf amplifier based on a dc SQUID (SQA) is tested in the frequency range 3.3-4.1 GHz. A new signal launching system for the SQA rf coupling has been developed and successfully implemented. The following parameters have been measured at 3.65 GHz using a band-pass filter at the input of a single-stage SQA: gain (11.0±1.0) dB, 3 dB bandwidth of 300 MHz and noise temperature (4.0±1.0)K. This figure corresponds to a flux noise S_Φ^½=0.6 μΦ₀/Hz^½ and an energy sensitivity ε_i≈75 h. The input saturation power, P_s, (1 dB gain compression) is measured for different bandwidths of the input band-pass filter, A corresponding input signal saturation temperature (normalized for a 1 GHz bandwidth) T_SAT^1GHZ=P_SAT/k_B is estimated to be 11.5 K GHz at an SQA bias voltage 27 μV (condition for minimum noise temperature). The dependencies of the SQA gain, noise temperature and saturation level on the operation point are studied. The reason for the SQA saturation is discussed

Keywords

SQUIDs; integrated circuit noise; microwave amplifiers; microwave integrated circuits; superconducting device noise; superconducting device testing; superconducting integrated circuits; superconducting microwave devices; 11 dB; 3 dB bandwidth; 3.3 to 4.1 GHz; 300 MHz; SQA rf coupling; band-pass filter; energy sensitivity; flux noise; input saturation power; input signal saturation temperature; low-noise S-band DC SQUID based amplifier; low-noise rf amplifier testing; minimum noise temperature condition; noise temperature; signal launching system; single-stage SQA; Band pass filters; Bandwidth; Frequency; Gain measurement; Low-noise amplifiers; Noise measurement; Radiofrequency amplifiers; SQUIDs; Temperature sensors; Testing;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.919574

Filename

919574