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 Rbolo for improved readout noise performance. The prototype system exhibits noise performance comparable to SPT-3G readout hardware when operating SPT-3G detectors.
@article{arxiv.1907.09035,
title = {Performance of a low-parasitic frequency-domain multiplexing readout},
author = {A. E. Lowitz and A. N. Bender and P. Barry and T. W. Cecil and C. L. Chang and R. Divan and M. A. Dobbs and A. J. Gilbert and S. E. Kuhlmann and M. Lisovenko and J. Montgomery and V. Novosad and S. Padin and J. E. Pearson and G. Wang and V. Yefremenko and J. Zhang},
journal= {arXiv preprint arXiv:1907.09035},
year = {2020}
}
Comments
7 pages, 4 figures. Submitted to J. Low Temp. Detectors