Research of local dynamics of the phase-locked loop

Abstract

Measures to reduce the influence of the dead zone of frequency-sensitive phase detector on frequency deviation of the signal generated by the phase-locked loop (PLL) the circuit of which includes the binomial low-pass filter of the fifth order, providing additional ripple suppression of control voltage are defined here. With the help of simulation method of Matlab program it was shown 60°...70° that to reduce the peak frequency deviation it is necessary to ensure the stability margin of the automatic system at phase. Given stability margin from 26° to 80° systematic frequency shift of the generated signal is observed, despite the fact that the system under consideration has astatism of the second order.