RAPID SINGLE-FLUX-QUANTUM BALANCED COMPARATOR BASED ON HIGH-T-C BICRYSTAL JOSEPHSON-JUNCTIONS

A balanced current comparator based on high-T-c bicrystal Josephson ju nctions has been designed, fabricated, and experimentally tested, The operation of the balanced comparator has been demonstrated in the temp erature range from 4.2 to 70 K. The correct sequence of switching of t he Josephson junctions has been determined by de measurements for diff erent values of operating frequency and signal current l(x). The thres hold uncertainty Delta I-x of the balanced comparator, measured at 40 K, was 60 mu A at 40 GHz and 300 mu A at 240 GHz. (C) 1996 American In stitute of Physics.