Some new developments of precision frequency measurement technique

In recent years, a distinguishing feature of developments of precision frequency measurement techniques is highly precise measurement of wider frequency range. In this paper conventional frequency standard comparison techniques and corresponding wide frequency measurement techniques developed in recent years are compared. Based on the study of the characteristics of the greatest common factor frequency and "phase coincidence" detection technique, the advantages of frequency standard comparison technique and comparison of two signals with the same nominal frequency can also be obtained in the frequency measurement of a very wide frequency range. In the application of the new techniques, some special design methods are used. They are: 1) the method combined "phase coincidence" detection method with no dead time measurement method; 2) in the measurement of some special frequency signals, the uses of regular distribution of "phase coincidence" between two frequency signals; 3) the method with which the noise of measuring device and the noise of measured oscillator are divided in frequency characteristics; 4) for higher precision some analog circuits can be used instead of digital circuits. This paper also analyses the possibility that the new technique and instruments are used instead of conventional digital frequency meters.