Apparatus for reducing low frequency noise in dc biased SQUIDS
US4389612A · kind A · utility
114Cited by
1References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1980 |
| Grant date | Jun 21, 1983 |
| Priority date | — |
| Expiry date | Jun 17, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S505/846
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit for reducing low frequency noise in a direct current biased superconducting quantum interference device. A squarewave bias signal having no dc component is used to bias the two junctions of the dc SQUID. At the same time, the magnetic flux in the SQUID is modulated to heterodyne the input signals up to some convenient frequency where they may be amplified without concern for drift. Final demodulation automatically adjusts for the fact that the relative phase is reversed each time the squarewave bias changes polarity states.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.