Combining Josephson Systems for Spectrally Pure AC Waveforms With Large Amplitudes

We present the combination of two Josephson waveform synthesizers to generate waveforms with low harmonic distortion [below $-$110 dBc (carrier)] and amplitudes above the 1-V level. Fast and flexible code programming enables pulse-driven Josephson arrays to synthesize arbitrary waveforms. We have used the pulse-driven system to cancel the harmonic content from the binary array that can reach 1-V amplitudes. The quantum nature of the Josephson synthesizer ensures very stable amplitudes (better than $6 \times 10^{-8}$) and no frequency drift. This performance, together with the ability to synthesize arbitrary waveforms, can make this synthesizer a relevant tool for characterizing precision electronics and ac voltage metrology.