Flux ramp modulation based hybrid microwave SQUID multiplexer

We present a hybrid microwave superconducting quantum interference device (SQUID) multiplexer that combines two frequency-division multiplexing techniques to allow given number of cryogenic detectors with only fraction frequency encoding resonators. Similar conventional SQUID multiplexing, our relies on inductively coupling non-hysteretic, unshunted rf-SQUIDs resonators as well applying flux ramp modulation for output signal linearization. However, instead utilizing one resonator per SQUID, we couple multiple SQUIDs common readout and encode the input signals in sidebands carrier by varying each SQUID. prove suitability approach using prototype argue means fundamental information theory is particularly suited reading out large bolometer arrays.