Design of series SQUID array suppressing Josephson oscillation interference between element-SQUIDs

We have designed and fabricated single-stage series SQUID arrays usable for current amplifiers with filtering resistors in its input coil. From experimental results, it was revealed that filtering in each SQUID in the array successfully suppressed the interference between element-SQUIDs. An array with 1000 SQUIDs showed relatively smooth flux-voltage curves, large voltage swing (/spl sim/50 mV) and current-voltage conversion coefficient (/spl sim/1000 V/A).