Bias conditions of dc-SQUIDs for a time-domain SQUID multiplexer
Joern Beyer, Dietmar Drunge, Kent D. Irwin
SQUID multiplexers can be used to read out arrays of cryogenic microcalorimeters and bolometers. Time-domain dc-SQUID multiplexer configurations use an individual first-stage dc-SQUID for each detector of an array. The biasing conditions of these first-stage SQUIDs significantly affect the performance of the SQUID multiplexer. We analyze the bias conditions of the first-stage SQUIDs in terms of the total multiplexer noise and bandwidth. We present an analysis and experimental study of the operational parameters of a first-stage dc-SQUID under varied vias conditions. This analysis includes a direct measurement of the SQUID dynamic resistance and the flux noise of the SQUID biased over the range from voltage bias to current bias. Our measurements show that a matched bias of the first-stage SQUIDs improves the system noise performance as well as the first-stage bandwidth.
, Drunge, D.
and Irwin, K.
Bias conditions of dc-SQUIDs for a time-domain SQUID multiplexer, Review of Scientific Instruments, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=31440
(Accessed December 8, 2023)