Patent ID: 6853243

Claim:
A wireless communication frequency signal amplification apparatus, comprising: a first path having at least one amplifier having a first semiconductor device at an output stage thereof; a second path having an output lower than that of the first path, and the second path having at least one amplifier having a second semiconductor device formed to accomodate a smaller output than an output of the first semiconductor device at an output stage thereof; a control circuit to control the paths so that the paths are operative one at a time; a branching circuit on an input side and a branching circuit on an output side of the paths for branching an input signal into an operative one of the paths in accordance with a desired output level of the apparatus; and a phase adjuster for adjusting a phase of the signal so that signal so that the phase of the signal through the first path when the first path is operative becomes substantially the same as the phase of the signal though the second path when the second path is operative.