Patent ID: 7593480

Claim:
A transmission apparatus using a polar modulation scheme, comprising: an amplitude phase separator that separates baseband modulation data into a baseband amplitude modulation signal and a baseband phase modulation signal; a phase modulator that modulates a high frequency carrier signal based on the baseband phase modulation signal and forms a high frequency phase modulation signal; a variable gain amplifier that is provided in a later stage of said phase modulator and amplifies the high frequency phase modulation signal; and a high frequency power amplifier that is provided in a later stage of said variable gain amplifier and amplifies power of the high frequency phase modulation signal amplified by said variable gain amplifier, wherein said variable gain amplifier comprises: a linear-log converter that linear-log converts the baseband amplitude modulation signal; and an amplifier that amplifies the high frequency phase modulation signal based on the linear-log converted baseband amplitude modulation signal and a gain control signal.