Evaluation of a Microwave SQUID Multiplexer Prototype

As large arrays of ultrasensitive cryogenic detectors of radiant energy are developed, multiplexing schemes are required to manage system complexity. Any such scheme must also meet stringent sensitivity, bandwidth, dynamic range and power dissipation specifications. We describe preliminary tests of a microwave frequency-division multiplexed readout of SQUID amplifiers. From these initial tests we estimated the number of SQUIDs that can be multiplexed with this scheme and the sensitivity and bandwidth of each SQUID amplifier.