The characterisation of a phase micro-stepper

Abstract

The frequency steering of the local standard time is a common procedure for the timekeeping. The local radiofrequency reference output is modified by a phase and frequency offset generator to corresponds to the global timescales such as the International Atomic Time (TAI) and Coordinated Universal Time (UTC) timescales. The phase and frequency offset generator, also known as the phase micro-stepper, is used for such timescales for many years but it has not been very well characterized metrologically. It will be shown for a particular type of the phase micro-stepper that its phase delay error can exceed 10 ps and its frequency offset error can be relatively more than 10-16 of the reference frequency.