Low noise bandwidth phase locked loop - uses addition of compensation circuit with few components to give improved noise performance

摘要

The phase-lock loop for locking to a reference signal, including a signal-controlled oscillator of which the output is connected to one input of a phase detector, and the reference signal to the other input, the output of the detector delivers a control signal which is fed back as the oscillator control signal through a loop filter. The phase-locking loop is also fitted with a phase compensation circuit having a compensation filter and a phase modulator, with the carrier input connected to the output of the signal-controlled oscillator and the modulation input via the compensation filter to the output of the phase detector, the output of the phase modulator is taken as the signal output of the phase-locked loop.