The measurement of transient stability with high resolution

Transient stability measurement of frequency source plays an important part in the real-time short-term stability and the characterization of distal phase noise, so its accurate measurement is of great significance. Measurement of transient noise and short-term stability of signals with the conventional digital counting methods is very difficult and the measurement accuracy is low. So we introduce a unique phase coincidence detection technology which is an important detection method and our group has worked on it for decade to measure the frequency source transient stability. When the phase difference of two signals is less than a certain value, phase coincidence detection circuit will output a narrow pulse which represents the phase coincidence, we call it the phase coincidence detection resolution threshold. When the phase difference of two signals is adjusted to the verge of coincidence detection resolution, we can judge the transient frequency stability of signals accurately from the continuity and discontinuity of the coincidence information. According to the results of multiple phase coincidence detection circuits which combine as a coincidence detection array, the phase variation in detail can be obtained. The measurement resolution depends on the stability of the coincidence detection circuit. This paper describes the principle, the experiment process and the results of transient stability measurement methods.