COMPARISON OF TIME BASE NONLINEARITY MEASUREMENT TECHNIQUES

Distortions in the timebases of equivalent-time oscilloscopes and digi tizers cause distortions of waveforms sampled by them. This paper repo rts on a comparison of two methods of characterizing timebase distorti on, using pure sine-wave inputs of known frequency: the ''sinefit'' an d the ''analytic signal'' methods. Simulations are used to compare the performance of the two methods versus different types of timebase dis tortion, different sine-wave frequencies, number of different sine-wav e phases, levels of random noise, and levels of random jitter, The per formance of the two methods varies considerably, dependent upon the in put signal frequency and type of timebase distortion. Each method does much better than the other for certain cases.