Fast Switching Frequency Synthesizer Employing Adaptive Phase Locked Loop

Abstract

This work describes a fast switching frequency synthesizer employing an adaptive second order phase locked loop whose damping ratio is taken as ??=0.707 while its natural frequency could be varied according to the step change in the division ratio of the programable counter to improve the switching time for large step change in the division ratio without degrading the noise rejection properties. The mathematical relationship which describes the behaviour of the system is carried out and the system is implemented assuming certain design values. The response of the system is obtained to show that the step change in the division ratio could be increased to ten times without skipping cycles in the loop.