Patent ID: 7634022

Claim:
A polar modulator, comprising: a power amplification section; a phase modulation section for generating a first modulated signal including phase information; an amplitude signal control section for generating a second modulated signal including amplitude information; a waveform shaping section for, when an amplitude of the second modulated signal is larger than a predetermined regulated value, generating a waveform-shaped modulated signal obtained as a result of shaping a waveform of the second modulated signal, such that the amplitude of a portion of the second modulated signal which exceeds the predetermined regulated value becomes equal to or smaller than the predetermined regulated value; a voltage control section for outputting a supply voltage; and an amplitude modulated voltage supply section for amplifying the waveform-shaped modulated signal using a transistor based on the supply voltage which is output from the voltage control section and for supplying the amplified signal to the power amplification section as an amplitude modulated voltage; wherein: the power amplification section amplifies the first modulated signal based on the amplitude modulated voltage, and thus outputs a third modulated signal obtained as a result of modulating an amplitude of the first modulated signal; and the waveform shaping section adjusts the predetermined regulated value in accordance with a factor for changing a distorted power generated by the power amplification section, such that an adjacent channel leakage power generated in the power amplification section becomes equal to or smaller than a first predetermined value, or such that a power at a receiving band becomes equal to or smaller than a second predetermined value.