Patent ID: 7714666

Claim:
A phase locked loop frequency synthesizer, comprising: a phase locked loop comprising: a detector receiving a reference signal and a feedback signal to generate a phase detection signal based on phase difference therebetween; a loop filter filtering the phase detection signal to generate a control signal; a voltage control oscillator generating a first output modulation signal with a frequency varying based on the control signal; and a frequency dividing unit varying a division factor based on a processed input modulation signal and dividing the frequency of the first output modulation signal by the division factor to generate the feedback signal; a frequency regenerator altering the frequency of first output modulation signal to generate a second output modulation signal with a frequency range not overlapping an output frequency range of the voltage control oscillator; and a modulation processor processing an input modulation signal to generate the processed input modulation signal to adjust the division factor of the frequency dividing unit, wherein the processing of the input modulation signal comprises compensating for distortion induced by the frequency regenerator, wherein the modulation processor comprises: a waveform generator performing pulse shaping on the input modulation signal; and a compensator compensating for distortion induced by the frequency regenerator.