Fabrication and operation of a 1024-stage voltage multiplier for ac voltage standard applications

We present fabrication and operation of a 1024-stage voltage multiplier (VM) that is the key subsystem of a rapid single flux quantum digital-to-analog converter for ac voltage standard applications. Our fabrication process has been improved to reduce inter- and intralayer short probabilities, which was a key to developing large-scale circuits. A 1024-stage VM including over 5000 junctions was fabricated using the improved process. Correct operation was confirmed at the input frequencies up to 34 GHz which corresponded to the maximum output voltage of 72 mV.