Digitizer nonlinearity correction with an AC Josephson Voltage Standard

High-fidelity conversion of physical measurement data to the digital domain is desirable in many fields of science. Numerous techniques are available for the correction of nonlinearities in analog-to-digital converters (ADCs). However, implicit in these methods is the availability of a source with a higher resolution and/or lower nonlinearity than that of the ADC under test, which is challenging to realize for ADCs with resolutions exceeding 20 bits. An AC Josephson Voltage Standard (ACJVS) is capable of generating pure tones with distortion below 1 part per billion and amplitude accuracies in the single parts per million. These characteristics make it an ideal source for evaluating nonlinearities in high-resolution digitizers commonly used in audio and dynamic force measurements. In this talk I will describe the framework for performing such nonlinearity corrections with the ACJVS, share results and limitations, and discuss possible ways that this technique can be used to account for phase distortion.