Josephson-Voltage-Standard-Locked Sine Wave Synthesizer: Margin Evaluation and Stability

This paper describes a Josephson-voltage-standard-locked synthesizer where a commercial digital-to-analog converter is used as a sine wave generator. The output amplitude of the generator is controlled by the calculable fundamental of the stepwise waveform generated by a SINIS Josephson junction array. Such a system combines the versatility of a commercial source with the stability and accuracy of the Josephson standard. By discarding the measurements performed during the transients, broad voltage steps of 1.7 mA were obtained up to frequencies of 500 Hz.