Adaptive dual loop phase lock loop with improved performance

Abstract

An adaptive dual loop phase locked loop (PLL) system with auto selection technique for fast acquisition, reliable locking and improved noise performance is proposed. The system utilizes the wide locking range properties and fast acquisition of the first order loop and enhanced noise performance of the second order loop. The simulation results confirmed the new system's ability to switch between 2nd and 1st order loops in order to acquire fast acquisition, while keeping the loop in lock. In this work, the system is designed to overcome the conflicting requirement of fast acquisition and improved noise performance. This technique is particularly desirable for communication and control applications.