A microwave SQUID multiplexer (μMUX) has been optimized for coupling to large arrays of superconducting transition-edge sensor (TES) bolometers. We present the scalable cryogenic multiplexer chip design in a 1820-channel multiplexer configuration for the 4-8 GHz rf band. The key metrics of yield, sensitivity, and crosstalk are determined through measurements of 455 readout channels, which span 4-5 GHz. The median white-noise level is 45 pA/Hz, evaluated at 2 Hz, with a 1/f knee ≤ 20 mHz after common-mode subtraction. The white-noise level decreases the sensitivity of a TES bolometer optimized for detection of the cosmic microwave background at 150 GHz by only 3%. The measured crosstalk between any channel pair is ≤ 0.3%.
@article{arxiv.2010.07998,
title = {A Microwave SQUID Multiplexer Optimized for Bolometric Applications},
author = {B. Dober and Z. Ahmed and K. Arnold and D. T. Becker and D. A. Bennett and J. A. Connors and A. Cukierman and J. M. D'Ewart and S. M. Duff and J. E. Dusatko and J. C. Frisch and J. D. Gard and S. W. Henderson and R. Herbst and G. C. Hilton and J. Hubmayr and Y. Li and J. A. B. Mates and H. McCarrick and C. D Reintsema and M. Silva-Feaver and L. Ruckman and J. N. Ullom and L. R. Vale and D. D. Van Winkle and J. Vasquez and Y. Wang and E. Young and C. Yu and K. Zheng},
journal= {arXiv preprint arXiv:2010.07998},
year = {2021}
}