| 摘要 |
PROBLEM TO BE SOLVED: To provide a power amplifier capable of materializing a high-efficiency amplification operation.SOLUTION: A Doherty amplifier 1 of the present invention comprises: a power distributor 11 which distributes an input signal into first and second distribution signals; a carrier amplifier 12 which amplifies the first distribution signal; a peak amplifier 13 which amplifies the second distribution signal when power of the second distribution signal is equal to or greater than predetermined power; an impedance converter 14 which converts impedance of respective outputs of the carrier amplifier 12 and the peak amplifier 13; and a variable phase shifter 15 provided on a first signal path where the carrier amplifier 12 is provided or on a second signal path where the peak amplifier 13 is provided, for changing a phase of a signal that passes through the variable phase shifter, in accordance with instantaneous power of the input signal.SELECTED DRAWING: Figure 1 |
