Patent ID: 7826811

Claim:
A two-point modulation type phase modulation apparatus for modulating a carrier frequency signal using an inputted digital baseband modulation signal by setting a frequency dividing ratio of a frequency divider of a PLL circuit based on the inputted digital baseband modulation signal, and adding a voltage corresponding to an analog-converted signal to the inputted digital baseband signal for supply to a control voltage terminal of a voltage controlled oscillator of the PLL circuit, comprising: a D/A converter that converts the inputted digital baseband signal to an analog signal; an adding section that adds an output signal of the D/A converter and an output of a loop filter of the PLL circuit, and outputs the addition signal to the control voltage terminal of the voltage controlled oscillator; and a peak control section provided at a front stage of the D/A converter, that carries out smoothing of peak portions appearing in the inputted digital baseband signal.