LI Yu-wei1,2,3, LIU Ya1,2,3, LI Xiao-hui1,2

(1. National Time Service Center, Chinese Academy of Sciences, Xi’an 710600, China;

2. Key Laboratory of Time and Frequency Primary Standards, National Time Service Center,

Chinese Academy of Sciences, Xi’an 710600, China;

3. Graduate University of Chinese Academy of Science, Beijing 100039, China)

Abstract: In order to evaluate the performance of symmetricom’s TSC MMS(multi-channel measurement system), which is a phase measurement device based on the measurement principle ofdual mixer time difference (DMTD) method, and to seek the method of improving the performance, a TSC MMS performance test platform was set up and the background noise in TSC MMS was measured. The measured background noise is consistent with that issued by the manufacturer, 2.5×10-13(10 MHz). Besides, the factors which affect the measurement results are analyzed.

Key words: multi-channel measurement system; frequency measurement; background noise; frequency stability