Frequency multiplexed flux locked loop architecture providing an array of DC SQUIDS having both shared and unshared components

摘要

Architecture for frequency multiplexing multiple flux locked loops in a system comprising an array of DC SQUID sensors. The architecture involves dividing the traditional flux locked loop into multiple unshared components and a single shared component which, in operation, form a complete flux locked loop relative to each DC SQUID sensor. Each unshared flux locked loop component operates on a different flux modulation frequency. The architecture of the present invention allows a reduction from 2N to N+1 in the number of connections between the cryogenic DC SQUID sensors and their associated room temperature flux locked loops. Furthermore, the 1xN architecture of the present invention can be paralleled to form an MxN array architecture without increasing the required number of flux modulation frequencies.