Equivalent-Time Sampling Oscilloscope Aliasing Analysis

摘要

The high speed PAM4 signals with repeating data pattern can be analyzed and measured on the equivalent-time sampling oscilloscopes. The harmonics not synchronous with the data pattern are aliased on the equivalent-time sampling oscilloscopes. The aliasing is analyzed, and a method is described to remove the unwanted aliased harmonics. The real-time oscilloscopes have the real-time sample rate high enough to prevent aliasing. A numerical example is given that compares the optical PAM4 TDECQ measurement on the equivalent-time sampling oscilloscopes and on the real-time oscilloscopes.