PLL with fuzzy logic nonlinear gain controller

Some uses of phase lock loops (PLL) are digital communication receivers and clock generators for integrated circuits. In this paper a novel PLL technique that demonstrates fast acquisition and noise reduction is shown. This is accomplished by the use of a nonlinear gain unit. The nonlinear gain unit is implemented by means of a fuzzy logic controller. The fuzzy logic controller is a nonlinear proportional controller. This allows for a large gain to reduce the locking time and a small gain for noise reduction. The controller can be designed by simple guidelines rather than design optimization.