| 摘要 |
PROBLEM TO BE SOLVED: To provide a power amplifier which is improved in efficiency and can be small-sized.SOLUTION: A power amplifier includes: a distributor which distributes a first signal into a second signal and a third signal delayed from the second signal substantially at 90°; a first amplifier which outputs a fourth signal by amplifying the second signal in a region where a power level of the first signal is equal to or higher than a first level; a second amplifier which outputs a fifth signal by amplifying the third signal in a region where the power level of the first signal is equal to or higher than a second level that is higher than the first level; a first phase shifter to which the fourth signal is inputted and which outputs a sixth signal delayed from the fourth signal substantially at 45°; a second phase shifter to which the fifth signal is inputted and which outputs a seventh signal advanced from the fifth signal substantially at 45°; and a multiplexing section which outputs an amplification signal of the first signal by multiplexing the sixth and seventh signals.SELECTED DRAWING: Figure 1 |
