A novel phase processing approach based on new concept and method

Conventional phase processing is only for the continuous phase comparison at the same nominal frequency. In this case the processing resolution is limited, PLL and synthesizer are complicated, and linking between ultra high and ultra low frequency signals is very difficult. In most cases the comparison and control of frequency signals occur between the different nominal frequencies. To two signals with different nominal frequencies, one is the reference signal and another is the measured and controlled signal. The phase variation period of them is their least common multiple period, T_minc (LCMP), and also expresses the phase variation of the measured signal against its nominal frequency signal. In T_minc between two period groups of the signals the average variation full period of all different phase differences is equal to the group phase variation between any two most adjacent phase coincidences. It is also equal to 1/AB T_minc, the equivalent phase comparison period T_equ = T_minc/AB. Here A and B are the divider between nominal frequency of the signals and their greatest common factor frequency (GCFF) respectively. Theoretically, the direct phase comparison can be completed between any different frequency signals, and the resolution can be very high. With a lot of experiments, the phase processing principle and approach have been proved to show some very important application values, for example, with higher frequency and phase measurement resolution, high-precision and more flexible PLL technique, and so on. The approach has been used in high- resolution frequency measurement instruments, high-precision PLL and phase measurement and control devices. It is easy to obtain ps to fs resolution and the frequency and phase processing is more flexible. With the approach the frequency signals with a big frequency difference, for example, even more than 10⁵ times, can be compared and processed directly.