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A TDMA Hybrid SQUID Multiplexer



Carl D. Reintsema, James A. Beall, W.Bertrand (Randy) Doriese, William Duncan, S. L. Ferreira, Gene C. Hilton, Kent D. Irwin, Dan Schmidt, Joel Ullom, Leila R. Vale, Yizi Xu


We have developed a multiplexed read-out for transition edge sensors based on a hybrid time- and frequency-domain basis set, similar to that used in time-division multiple-access (TDMA) mobile phones. The hybrid basis set uses bandwidth more efficiently than microwave frequency-division SQUID multiplexing, making it possible to multiplex more detectors in each output line. The high open-loop bandwidth provided by our SQUID TDMA system also makes it possible to multiplex large arrays of fast, high dynamic range detectors such as fast x-ray calorimeters. In this approach, we embed the 2nd stage SQUID amplifier of our standard time-division multiplexer in an impedance matching circuit to couple signal into a broadband cryogenic HEMT amplifier in a microwave reflectometer configuration. The input signals are flux coupled into the 1st stage SQUID amplifiers whose signals are time-division multiplexed into the 2nd stage SQUID. At room temperature, the signal from the HEMT is mixed down to dc for analysis and further signal processing.
Journal of Low Temperature Physics


SQUID multiplexer, TES bolometer, detector array readout


Reintsema, C. , Beall, J. , Doriese, W. , Duncan, W. , Ferreira, S. , Hilton, G. , Irwin, K. , Schmidt, D. , Ullom, J. , Vale, L. and Xu, Y. (2008), A TDMA Hybrid SQUID Multiplexer, Journal of Low Temperature Physics, [online], (Accessed April 15, 2024)
Created January 24, 2008, Updated October 12, 2021