Fractional-order phase-locked loop

In this paper, a fractional-order analog phase-locked loop (FAPLL) model is proposed. In the new model, the traditional analog phase locked loop (APLL) is generalized by allowing the loop filters as well as the voltage controlled oscillators to acquire fractional order dynamics. The new model offers superior performance compared to its integer order counterpart in terms of capture and locking time response. The improvement realized in the response of the FAPLL outweighs the slight increase in the loop bandwidth, typically seen in fractional order systems. The main points of this work are illustrated via numerical examples.