Voltage doubler cell for rapid single flux quantum digital-to-analog converter

Digital-to-analog converters based on rapid single flux quantum circuits (RSFQ-D/A converters) are candidates for the next generation of ac voltage standard. We re-optimized the device parameters of a voltage multiplier (VM) cell, one of the important components in the RSFQ-D/A converter, to implement a new voltage doubler (VD) cell. The output voltage of the VD cell was twice as high as that of the conventional VM cell. We fabricated VD cells using a Nb technology. We confirmed correct operation of the VD cells at input frequencies up to 30 GHz.