Title:
READOUT CIRCUIT AND METHOD FOR DIRECT-READING FLUX MODULATION
Document Type and Number:
WIPO Patent Application WO/2017/128706
Kind Code:
A1
Abstract:
A readout circuit (2) for direct-reading flux modulation comprises a SQUID (21); a pre-amplifier (22) configured to amplify an output signal of the SQUID (21); a high-pass filter (23) configured to filter out a direct current component and low-frequency noise; a modulation/demodulation signal generator (24); a demodulator (25) configured to demodulate an output signal of the high-pass filter (23); an integrator (26) configured to integrate and generate a response voltage signal; and a feedback module (27) configured to feed back the response voltage signal to the SQUID (21). Also provided is a readout method for direct-reading flux modulation. In the method, modulation is used to enable an operating point of the SQUID (21) to jump between two operating points having opposite variation trends, and a tested signal is amplified, high-pass filtered, demodulated, integrated, and then fed back to the SQUID (21), so as to lock the operating point. The circuit (2) of the present invention realizes separation of low-frequency noise and output direct current bias of the pre-amplifier (22) by using the high-pass filter (23); avoids decrease in the SQUID flux-voltage conversion coefficient due to load effect; does not generate higher harmonic distortion on a SQUID flux-voltage curve; avoids thermal noise issues of transformers; and boasts a simplified circuit structure and higher practicability.
Inventors:
RONG LIANGLIANG (CN)
ZHANG YI (CN)
JIANG KUN (CN)
WANG YONGLIANG (CN)
WU JUN (CN)
XIE XIAOMING (CN)
ZHANG YI (CN)
JIANG KUN (CN)
WANG YONGLIANG (CN)
WU JUN (CN)
XIE XIAOMING (CN)
Application Number:
PCT/CN2016/096327
Publication Date:
August 03, 2017
Filing Date:
August 23, 2016
Export Citation:
Assignee:
SHANGHAI INST MICROSYSTEM & INFORMATION TECH CAS (CN)
International Classes:
G01R33/035; H01L39/24
Foreign References:
| CN105676152A | 2016-06-15 | |||
| JPH04268471A | 1992-09-24 | |||
| US6448767B1 | 2002-09-10 | |||
| CN103389478A | 2013-11-13 | |||
| CN102353911A | 2012-02-15 | |||
| CN102426343A | 2012-04-25 | |||
| JP2004157092A | 2004-06-03 | |||
| JPH0499980A | 1992-03-31 | |||
| US20030016010A1 | 2003-01-23 |
Attorney, Agent or Firm:
J.Z.M.C. PATENT AND TRADEMARK LAW OFFICE (CN)
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