Flat-Spot Measurements for an Ac Josephson Voltage Standard

Recent advances in circuit design and fabrication of superconducting integrated circuits have enabled us to demonstrate for the first time an ac Josephson voltage standard (ACJVS) that generates both ac and dc waveforms up to 242 mV peak voltage. Using a FFT (fast Fourier transform) spectrum analyzer and an ac/dc transfer standard, we characterize ACJVS operating margins by performing "flat-spot" measurements at the level of a part in 10
⁶
for all eight bias parameters