Print HE Zhen-zhong1,2,3, LI Xiao-hui1,2, LIU Ya1,2
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 Sciences, Beijing 100039, China
Abstract: Because of the restriction of Nyquist sampling theorem, it is difficult to measure the high-frequency signal accurately with the traditional high-precision digital frequency measuring instrument. A high-precision wide-range digital frequency measuring system is developed by the authors, which can conquer the restriction of Nyquist sampling theorem. In this system, the signal is measured through a preliminary process based on the frequency spectrum analysis as well as a precise process based on the low sampling rate method. A 10 MHz signal was measured with the high-precision wide-range digital frequency measuring system, and the measurements show that the relative frequency deviation and the stability are 1.13×10-11 and 1×10-12 respectively.
Key words: digitalizing; low sampling rate; high-precision frequency measurement