| 摘要 |
<p>Provided is a power amplifier which outputs a highly accurate signal. The power amplifier employs a polar modulator (102) and includes a difference component compensation circuit (201) in a stage before the power amplifier (108) whose power is modulated by a power modulator (109). The difference component compensation circuit (201) superposes a difference component (119) of the output signal from the power modulator (109) on the modulated wave for output to the power amplifier (108). A difference component (207) contained in the output from the difference component compensation circuit (201) is amplified by the power amplifier (108) and is outputted. The power amplifier (108) is subjected to power supply modulation by the output signal containing the difference component (119) from the power modulator (109) and the difference component (120) is superposed on the output signal of the power amplifier (108). The difference component (208) outputted from the difference component compensation circuit (201) and amplified by the power amplifier (108) is cancelled by the difference signal (120) of the power amplifier output generated by the power modulation by the power amplifier (108), thereby suppressing the difference component of the power amplifier output.</p> |
