Patent ID: 8290454

Claim:
A power amplification device, comprising: a variable phase shifter circuit for changing a phase of an input signal having envelope variation to thereby generate a base signal; a first adder circuit for vector-adding a first constant envelope vector generating signal having a phase advanced by Ï€/2 from the base signal to the base signal to thereby generate a first constant envelope signal; a second adder circuit for vector-adding a second constant envelope vector generating signal having a phase delayed by Ï€/2 from the base signal to the base signal to thereby generate a second constant envelope signal; a first amplifier circuit for amplifying the first constant envelope signal to thereby generate a first amplified signal; a second amplifier circuit for amplifying the second constant envelope signal to thereby generate a second amplified signal; a first amplitude detection circuit for detecting an amplitude of the first amplified signal and generating a first detected amplitude signal; a second amplitude detection circuit for detecting an amplitude of the second amplified signal and generating a second detected amplitude signal; a first amplitude control circuit for changing an amplitude of the first constant envelope vector generating signal and an amplitude of the second constant envelope vector generating signal, based on the first detected amplitude signal and the second detected amplitude signal, respectively; an output adder circuit for vector-adding the first amplified signal and the second amplified signal to thereby generate an output signal having amplified envelope variation; and a shift amount control circuit for detecting a phase difference between the input signal and the output signal and generating a shift amount control signal for controlling a shift amount by the variable phase shifter circuit according to the phase difference.