Computer simulation of a voltage cell using a Josephson junction

A single voltage cell, made with an oxide Josephson junction that is excited with an RF signal has been evaluated numerically in order to optimize various circuit parameters for ultimate application in a multijunction voltage standard. This voltage cell consists of a single junction shunted by a resistive stripline. From the single junction behavior, some reasonable design constraints on multijunction voltage standards have been extrapolated. It is seen that, in the framework of a multijunction voltage standard, the keys to a good design are the minimization of circuit inductances and the optimization of the internal resistance of the driving generator. Failure to do so may result either in the appearance of very high-frequency oscillations or in excessive crosstalk between cells. It is shown that a conservative design for the individual voltage cell is physically realizable, and will allow controllable interconnection of multiple cells into a voltage standard.