Patent attributes
A polar modulation transmission apparatus for realizing a wide control range for transmission power, maintaining the modulation precision and the distortion characteristic at a superb level even at a low output, and providing a high power efficiency is provided. An adder 102 adds a logarithm-represented transmission power control signal S13 to a logarithm-represented amplitude signal S14, and outputs the resultant signal as a transmission power-controlled amplitude signal S5. A phase modulation section 104 outputs a high frequency phase-modulated signal S8 based on a phase signal S3. An amplitude signal amplifier 103 supplies a supply voltage to a high frequency power amplifier 106 based on an amplitude signal S5. The high frequency power amplifier 106 performs amplitude modulation on the high frequency phase-modulated signal S8 based on the supply voltage supplied thereto, and outputs the resultant signal as a high frequency transmission signal S10.
