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arXiv · 1907.09035

Performance of a low-parasitic frequency-domain multiplexing readout

A. E. Lowitz·A. N. Bender·P. Barry·T. W. Cecil·C. L. Chang·R. Divan·M. A. Dobbs·A. J. Gilbert·S. E. Kuhlmann·M. Lisovenko·J. Montgomery·V. Novosad·S. Padin·J. E. Pearson·G. Wang·V. Yefremenko·J. Zhang
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Abstract

Frequency-domain multiplexing is a readout technique for transition edge sensor bolometer arrays used on modern CMB 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 improving 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, which enables better optimization of R$_{\rm{bolo}}$ for improved readout noise performance. The prototype system exhibits noise performance comparable to SPT-3G readout hardware when operating SPT-3G detectors.

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A. E. Lowitz, A. N. Bender, P. Barry, T. W. Cecil, C. L. Chang, R. Divan, M. A. Dobbs, A. J. Gilbert, S. E. Kuhlmann, M. Lisovenko, J. Montgomery, V. Novosad, S. Padin, J. E. Pearson, G. Wang, V. Yefremenko, J. Zhang. 2019-07-21. Performance of a low-parasitic frequency-domain multiplexing readout. https://doi.org/10.1007/s10909-020-02384-8

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