Software-assisted phase locking technique for Programmable Josephson Voltage Standard

In this paper, a novel phase-locking technique is used to interface a Programmable Josephson Voltage Standard (PJVS) with a Keysight U8930B Performance Audio Analyzer. This technique uses both hardware and software to phase-lock the PJVS to the analyzer via a master clock. Both long term stability and nulling measurements were performed on the analyzer. The long term stability results indicated that the lowest Allan deviation was achieved after 500 s of sampling. The long term stability provides a springboard for the nulling measurements. The nulling measurements allows the possibility for the U8903B to be used as a reliable transfer of the ac quantum voltage standard.