Characterization of an analog-to-digital converter frequency response by a Josephson arbitrary waveform synthesizer

The capability to generate up to 1 V pure AC signals based on quantum standards marked a milestone on electrical metrology opening new applications that were not possible without this standard. Frequency response characterization of analog-to-digital converters (ADC) is fundamental for precision digital metrology. Several methods have been investigated for this characterization based on thermal converters, programmable Josephson voltage standard or input impedance measurements. This paper describes the method, the results obtained and the uncertainty estimation for the characterization of the amplitude frequency response at different aperture times of the DCV sampling function of the Keysight 3458-A using, for the first time, a Josephson arbitrary waveform synthesizer. This new standard allows one to extend the characterization to a higher frequency range and lower aperture times. The results show that the frequency response does not depend on aperture time and the same frequency correction can be applied in an extended frequency range. The knowledge of this correction will facilitate the application of the ADCs to higher frequencies, where low aperture times are required with accuracy in the order of V/V.