Patent ID: 7368985

Claim:
A high frequency power amplifier comprising: a power amplifier to amplify a digitally modulated high frequency signal; an envelope detection portion to generate an envelope signal equivalent to an envelope voltage for the high frequency signal; a comparator to compare the envelope signal with a specified reference signal; and a power converter circuit to convert a power supply voltage into power in accordance with an output from the comparator, wherein a voltage output from the power converter circuit is used as a power supply voltage for the power amplifier, wherein a fixed reference voltage is used as the specified reference signal, wherein the power converter circuit, in accordance with an output from the comparator, selectively outputs a first voltage and a second voltage higher than the first voltage based on the power supply voltage, wherein the power converter circuit includes: a first DC-DC converter which is supplied with a two-state output from the comparator, outputs a 0-voltage when the output is corresponds to a first level, and outputs an additional voltage when the output corresponds to a second level; a second DC-DC converter which always outputs the same output direct current voltage with reference to the power supply voltage; and a voltage adder which adds outputs from the first and second DC-DC converters to each other for output.