Performance of a Low-Parasitic Frequency-Domain Multiplexing Readout

• Published in: Journal of low temperature physics Vol. 199; no. 1-2; pp. 192 - 199
• Main Authors: Lowitz, A. E., Bender, A. N., Barry, P., Cecil, T. W., Chang, C. L., Divan, R., Dobbs, M. A., Gilbert, A. J., Kuhlmann, S. E., Lisovenko, M., Montgomery, J., Novosad, V., Padin, S., Pearson, J. E., Wang, G., Yefremenko, V., Zhang, J.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-04-2020; Springer Nature B.V
• Subjects: Bolometers; Characterization and Evaluation of Materials; Condensed Matter Physics; Cosmic microwave background; Crosstalk; Frequency domain analysis; Low temperature physics; Magnetic Materials; Magnetism; Modules; Multiplexing; Noise; Physics; Physics and Astronomy; Sensor arrays; Transition-edge sensors; Frequency-domain multiplexing; Cosmic microwave background
• ISSN: 0022-2291; 1573-7357
• DOI: 10.1007/s10909-020-02384-8

Frequency-domain multiplexing is a readout technique for transition-edge sensor bolometer arrays used on modern cosmic microwave background experiments, including the SPT-3G receiver. Here, we present design details and performance measurements for a low-parasitic frequency-domain multiplexing readout. Reducing the parasitic impedance of the connections between cryogenic components provides a path to improve both the crosstalk and noise performance of the readout. Reduced crosstalk will in turn allow higher-multiplexing factors. We have demonstrated a factor of two improvement in parasitic resistance compared to SPT-3G hardware. Reduced parasitics also permits operation of lower-resistance bolometers optimized for improved readout noise performance. We demonstrate that a module in the prototype system has comparable readout noise performance to an SPT-3G module when operated with dark TES bolometers in the laboratory.