Frequency Measurement Research For Super High Resolution Based On Phase Processing

The time-frequency measurement and control technology has been widely used in many fields including aerospace, communication, navigation, measurement, space technology and geological exploration. Therefore, the study on the time-frequency measurement and control is very significant. In the measurement and control of time-frequency, compared with other all kinds of time-frequency measurement and control methods, phase comparing technology usually can obtain the highest measurement accuracy and resolution. However, traditional phase comparing technology is not used widely, it is difficult to be applied to complex frequency signals and the accuracy can't satisfy the technological requirement. So, the phase comparison technology development is limited seriously and even other fields' development. Therefore, we need to seek new measurement and control methods to remedy the deficiency of phase comparing technology, so the digitalization reconstruction method on phase coincidence detection frequency measurement is discovered at the proper moment.The digitalization reconstruction measurement method is a new measure-control method based on traditional phase comparing technology, fuzzy area and the border effect of fuzzy area. On the analysis of coincidence pulse signals by phase coincidence detection circuits, using four counters to reference signal and the measured signal measured in gate for continuous counter measurement in continuous counting module,at first we should measure the frequency value of the signal measured, then make a series of data processing on the frequency value and remove the bias value from the frequency value reconstruct a signal whose frequency value equals standard value of the signal to be measured and make sure that phase comparison between them can be made with owning same standard frequency value, and further improve the measurement accuracy to overcome the deficiency of traditional phase comparison methods. Because the signal reconstructed is unreal, we call it “reconstructed” signal.In this paper,introducing some basic theory about fuzzy area and its border effect, stress out the method of frequency measurement based on phase coincidence detection and the digitalization reconstruction theory and its implement method for further improving resolution ratio, and then make an analysis of data. At the same time, we can obtain directly the phase conversion information between two signals to be compared. This method can improve both accuracy of measurement and resolution ratio in the measurement of frequency, and maintain an order of magnitudes of 10-12 stably. In fact this method combines the advantages of high-accuracy(the accuracy will be improved sharply with time going on) measurement of phase comparison technology only based on the same frequency standard value and wide frequency range when measuring frequency, and can promote the comparison accuracy of any frequency signal during a long time and its frequency stability reaches-1810 / day.