Stepwise waveform synthesis using a programmable Josephson junction array

A waveform synthesizer adopting a programmable Josephson voltage standard has been developed, which can produce stepwise sinusoidal waveforms with few hundred quantum voltage levels. For synthesis of waveforms, individual cells on the Josephson array chip were promptly biased using a 7-channel current source with 14-bit resolution. As an application, the synthesizer was utilized as a fast-reversed DC voltage source in evaluating the thermoelectric transfer difference for a thermal voltage converter.