Title :
A dc SQUID based low-noise 4 GHz amplifier
Author :
Prokopenko, G.V. ; Shitov, S.V. ; Koshelets, V.P. ; Balashov, D.B. ; Mygind, J.
Author_Institution :
Inst. of Radio Eng. & Electron., Acad. of Sci., Moscow, Russia
fDate :
6/1/1997 12:00:00 AM
Abstract :
The dc SQUID based RF amplifier (SQA) looks very attractive as an IF amplifier for integration with a SIS mixer and a flux-flow oscillator (FFO) in a fully superconducting submillimeter wave receiver suitable for space applications. Important advantages of the SQA are its low noise, extremely low power consumption, and complete compatibility with the fabrication process currently used for SIS mixers. Single stage amplifiers with a novel signal coupling circuit have been developed and tested in the frequency range 3.6-4.1 GHz. The 1 /spl mu/m/sup 2/ area Nb-AlO/sub x/-Nb junctions shunted by Ti resistors are grouped in a double washer dc SQUID. Two samples with slightly different designs showed the following gain, noise temperature and 3 dB bandwidth: 10.0/spl plusmn/1 dB, 5.0/spl plusmn/1.5 K, 3.86-3.90 GHz, and 6.8/spl plusmn/1 dB, 22/spl plusmn/7 K, 3.89-4.05 GHz, respectively.
Keywords :
SQUIDs; aluminium compounds; coupled circuits; microwave amplifiers; niobium; space vehicle electronics; superconducting device noise; superconducting microwave devices; 3 dB bandwidth; 3.6 to 4.1 GHz; 3.86 to 3.90 GHz; 3.89 to 4.05 GHz; 5.8 to 7.8 dB; 9.0 to 11.0 dB; IF amplifier; Nb-AlO-Nb; RF amplifier; dc SQUID; double washer; noise; noise temperature; power consumption; signal coupling circuit; single stage amplifiers; space applications; superconducting submillimeter wave receiver; Circuit noise; Circuit testing; Energy consumption; Low-noise amplifiers; Oscillators; Radiofrequency amplifiers; SQUIDs; Submillimeter wave circuits; Superconducting device noise; Superconducting devices;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
