Waveform sampling of free-running frequency prescaled microwave signals by using delay-line-free electro-optic probing technique

We report for the first time the characterization of microwave frequency divider by using a delay-line-free electro-optic sampling system with a voltage-controlled phase-tunable circuit. The distorted waveform of the ECL signal frequency-prescaled from microwave oscillator operated at high output level is sampled. The divisor of the frequency prescalar is found to vary from 2 to 5 at input power of less than -14 dBm.