An experimental Josephson digital correlator

A circuit capable of performing correlation of two sets of 16-sample, one-bit digital data has been designed and tested up to a clock frequency of 12 GHz. The correlator consists of two 16-b shift registers for delay and storage elements and an array of 16 exclusive-OR gates for the multiply-and-add function. It is fabricated using an Nb/AlO/sub x//Nb Josephson-junction process at a critical-current density of 1000 A/cm/sup 2/.<
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