Analysis And Application Design Of RF PLL Frequency Synthesizer

RF signal source is an important element of a communication system, whose performance will influence the equipment's performance, especially the sentivity and the selectivity of the receiver. The continuous development of communication system has maken a higher and higher demand on the stability and accuracy of the signal source. The PLL frequency synthesizing technic, which develops fast recent years, has been the main design scheme of signal source, because of its performance advantage.Frequency synthesizing technic development and performance indexes are introduced in the paper firstly. Then the operating principle and linearized model are presented, and the influences of system paramenters on the loop performances are discussed. Thirdly, the influnces of the loop filter model on the loop performance are analyzed, and the loop filter parameters come out, based on the GSM RF characteristics. The stability model phase noise model and transient response model are created using RF simulation tool ADS. Based on simulation results, the loop filter parameters are fixed. Lastly, a verifying electrocircuit is achieved, and verifying experiment is done. The main performances are achieved according to the experimenting results.Systematic principle analyses and simulation of PLL frequency synthesizer are carried out, a verifying circuit is designed and finished. The results in the paper offer some reference ideas for the project practice.