Patent ID: 7382201

Claim:
A signal generating apparatus, for generating a synthesized signal according to an input signal, comprising: a phase-locked loop device, comprising: a phase/frequency detector, for generating a detected signal according to a reference oscillating signal and a feedback signal; a control signal generator, coupled to the phase/frequency detector, for generating a control signal according to the detected signal; a voltage controlled oscillator, coupled to the control signal generator, for generating the synthesized signal according to the control signal; and a divider, coupled to the voltage controlled oscillator, for dividing the synthesized signal according to a dividing factor for generating the feedback signal; a control unit, coupled to the control signal generator, for controlling the control signal generator to adjust the control signal in a calibration mode to thereby adjust a frequency of the synthesized signal, wherein the phase/frequency detector does not output the detected signal to the control signal generator in the calibration mode; a detecting device, coupled to the voltage controlled oscillator, for detecting the synthesized signal to generate a calibrating signal in the calibration mode; a filtering device, coupled to the detecting device, for filtering the input signal and calibrating the input signal according to the calibrating signal to generate a filtered signal; and a modulating device, coupled to the filtering device and the divider, for modulating the filtered signal to generate the dividing factor.