Strong Attenuation of the Transients´ Effect in Square Waves Synthesized With a Programmable Josephson Voltage Standard

This paper addresses the effect of transients on the operation of a 1-V programmable Josephson voltage standard for frequencies ranging between 125 Hz and 4 kHz. A detrimental effect of the transients occurring during the transition between different voltage steps is to make the ac Josephson voltage dependent on the bias current in the junctions. In other words, the current margins where the array behaves as a quantum standard are reduced to zero: the voltage steps have a slope. However, by using square waveforms, the effect of the transients can be reduced to a level where this slope is no longer measurable. This observation will probably lead to a simplification in the development of a new type of high-precision Josephson-based waveform synthesizer.