Analysis of Phase Noise of Phase-Locked Loops Under Different Frequency Discrimination

This paper introduces the contribution of the phase noise of the frequency phase discriminator, the frequency divider, and the input reference signal to the phase noise of the synthesized output signal in the phase-locked loop system. Then, we analyze the phase noise and frequency instability (Allan Deviation) of the phase-locked loop system under different frequency discrimination. The phase-locked loop system was tested at 5 MHz, 10 MHz, and 40 MHz frequency detection through the phase noise analyzer, which proved that the higher the frequency detection, the lower the residual phase noise and frequency instability of the system.