Abstract: This article introduces a phase-locked loop circuit that uses VCO to achieve frequency modulation,
The principle of direct frequency modulation of varactor diode - the diode can change the width of the space charge region by changing the applied reverse voltage,
Phase locked frequency stabilization technology - For direct frequency modulation circuits with variable capacitance diodes,
The loop only works on the part that causes instability of the average center frequency of the voltage controlled oscillator,
The phase-locked frequency stabilization circuit - phase detector is the core part of frequency stabilization
From the previous analysis, it can be seen that the phase-locked loop is a narrowband carrier tracking loop
