| 摘要 |
PROBLEM TO BE SOLVED: To provide a power amplifier device capable of performing efficient amplification and efficiently reducing high-frequency noise of an output signal with simple constitution. SOLUTION: Signals which are efficiently amplified by amplifier circuits 120A and 120B by using a switching system are passed through LPFs 130A and 130B to generate a positive-phase signal S3A wherein high-frequency noise including positive-phase switching noise remains and an opposite-phase signal S3B wherein high-frequency noise including opposite-phase switching noise remains. The positive-phase signal S3A is put together with opposite-phase switching noise, having a frequency nearby a switching frequency which is extracted from the opposite-phase signal S3B, by a composite filter 140A, and also has its high-frequency noise reduced. The opposite-phase signal S3B is put together with positive-phase noise, having a frequency nearby the switching frequency which is extracted from the positive-phase signal S3A, by a composite filter 140B, and also has the high-frequency noise reduced. COPYRIGHT: (C)2008,JPO&INPIT
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