Jitter measurement apparatus and its method

摘要

A signal under measurement is converted into a digital signal by an AD converter, and a band-pass filtering process is applied to the digital signal to take out only components around a fundamental frequency of the signal under measurement. A data around a zero-crossing of the components around the fundamental frequency is interpolated to estimate a timing close to a zero-crossing point. A difference between adjacent timings in the estimated zero-crossing timing sequence is calculated to obtain an instantaneous period data sequence. A period jitter is obtained from the instantaneous period data sequence.