Josephson Based Spectrum Analyzer

Differential measurements relative to a Josephson waveform provide very accurate measurements of ac waveforms. Pulse driven arrays, used in Josephson Arbitrary Waveform Synthesizers, can generate sine waves with very high spectral purity. These two Josephson based measurement tools can be combined to study undesired distortion components present in the frequency spectrum of high quality waveform generators. For a proof of principle experiment, we cancelled the fundamental tone of a waveform and measured the third harmonic that was generated.