The Simons Observatory (SO) is an upcoming polarization-sensitive Cosmic Microwave Background (CMB) experiment on the Cerro Toco Plateau (Chile) with large overlap with other optical and infrared surveys (e.g., DESI, LSST, HSC). To enable the readout of \bigO(10,000) detectors in each of the four telescopes of SO, we will employ the microwave SQUID multiplexing technology. With a targeted multiplexing factor of \bigO{(1,000)}, microwave SQUID multiplexing has never been deployed on the scale needed for SO. Here we present the design of the cryogenic coaxial cable and RF component chain that connects room temperature readout electronics to superconducting resonators that are coupled to Transition Edge Sensor bolometers operating at sub-Kelvin temperatures. We describe design considerations including cryogenic RF component selection, system linearity, noise, and thermal power dissipation.
@article{arxiv.2003.08949,
title = {Simons Observatory Microwave SQUID Multiplexing Readout -- Cryogenic RF Amplifier and Coaxial Chain Design},
author = {Mayuri Sathyanarayana Rao and Maximiliano Silva-Feaver and Aamir Ali and Kam Arnold and Peter Ashton and Bradley J. Dober and Cody J. Duell and Shannon M. Duff and Nicholas Galitzki and Erin Healy and Shawn Henderson and Shuay-Pwu Patty Ho and Jonathan Hoh and Anna M. Kofman and Akito Kusaka and Adrian T. Lee and Aashrita Mangu and Justin Mathewson and Philip Mauskopf and Heather McCarrick and Jenna Moore and Michael D. Niemack and Christopher Raum and Maria Salatino and Trevor Sasse and Joseph Seibert and Sara M. Simon and Suzanne Staggs and Jason R. Stevens and Grant Teply and Robert Thornton and Joel Ullom and Eve M. Vavagiakis and Benjamin Westbrook and Zhilei Xu and Ningfeng Zhu},
journal= {arXiv preprint arXiv:2003.08949},
year = {2020}
}