Quantum waveform synthesizer using Nb/TiN/Nb binary-divided Josephson junction arrays

This paper describes the development of a quantum waveform synthesizer operating at a sampling frequency of 100 kHz with the aim of generating sine waves directly traceable to the Josesphson quantum voltage standard. The quantum reference is based on arrays of 65 536 Josephson junctions, fabricated using Nb/TiN/Nb technology and operating at a bias frequency of 16 GHz corresponding to an output voltage of approximately 2.2 V. The synthesizer contains a specially constructed difference amplifier, digital source and anti-imaging filter. The type A uncertainty is estimated to be 40 nV for a 1s observation time.