A low-noise, two-stage DC SQUID amplifier with high bandwidth and dynamic range

Author

Cantor, R. ; Lee, L.P. ; Matlashov, A. ; Vinetskiy, V.

Author_Institution

Conductus Inc., Sunnyvale, CA, USA

Volume

7

Issue

2

fYear

1997

fDate

6/1/1997 12:00:00 AM

Firstpage

3033

Lastpage

3036

Abstract

We describe a low-noise, two-stage dc Superconducting QUantum Interference Device (SQUID) amplifier that is designed for applications requiring high bandwidth and dynamic range. The output signal of a low-noise SQUID in the input stage coherently modulates a series array of identical SQUIDs in the output stage via a common modulation line. The input stage is designed so its output signal does not produce multiple modulation periods in the output stage. The output stage is designed to have sufficient gain so the output noise is dominated by the amplified noise of the input SQUID and exceeds the noise of a preamplifier in the room temperature readout electronics. The SQUID amplifier may therefore be operated without flux modulation or any impedance matching network, resulting in a large dynamic range and high bandwidth.

Keywords

SQUIDs; superconducting device noise; wideband amplifiers; bandwidth; dynamic range; flux modulation; impedance matching network; low-noise two-stage DC SQUID amplifier; room temperature readout electronics; series array; Bandwidth; Dynamic range; Interference; Low-noise amplifiers; Preamplifiers; SQUIDs; Signal design; Superconducting device noise; Superconducting devices; Temperature;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.621971

Filename

621971