Research Of A New System For Phase Noise Measurement

With frequency standards widely used, the phase noise is described here in great detail after reviewing some other characteristics. Many researchers study on phase noise measurement for its importance in measurement, control and instrumentation. In traditional ways of phase noise measurement, the frequency sources to be measured should be of the same frequency as the references, which increases the complication and cost in system design. A new principle of Equivalent Phase Comparison Frequency(EPCF) has been put out here as a basis of a new phase noise measuring system. Using phase comparison between two signals in different frequencies, the phase noise can be obtained through signal processing.The circuit design of Phase-Locked Loop(PLL) based on EPCF, which has been given in the third chapter, is the key point in the new phase noise measuring system. The locking experiment shows that the new system can be implemented practically. The fifth chapter puts out the solution of effect of the greatest common factor frequency, which exists in the new method. Using this PLL, phase comparison and phase lock between signals in different frequencies can be implemented, which shows the advantages in its simplicity and low cost compared with the traditional phase noise measuring system.