Voltage lead corrections for a pulse-driven ac Josephson voltage standard

We present measurements on a pulse-driven ac Josephson voltage standard (ACJVS) for frequencies up to 1 MHz. By automating our setup we were able to perform a systematic study of the frequency dependence of the ACJVS output. We show that the error caused by the voltage leads is the major error source when measuring at frequencies up to 1 MHz. The squared frequency dependence of the error, which is caused by a resonance in the circuit, allows us to make a correction that results in an uncertainty on the mu V V-1 level for frequencies up to at least 20 kHz.