| 摘要 |
Provided is a power amplifier receiving and amplifying a radio frequency (RF) signal from an input terminal and outputting an amplified RF signal. The power amplifier comprises: an RF power amplification unit configured to amplify the RF input signal; a metal-oxide semiconductor field-effect transistor (MOSFET) configured to have a source supplied with a first direct current (DC) power, a gate that receives the RF input signal, and a drain connected to a power supply terminal of the RF power amplification unit; a power detection unit configured to detect the amplitude of the RF input signal and generate an envelope signal based on the detected amplitude; a supply voltage modulation control unit configured to determine a DC gate voltage of the MOSFET based on the envelope signal; and a bypass circuit including a first end connected to the drain of the MOSFET and a second end connected to the power supply terminal of the RF power amplification unit. The MOSFET outputs a second DC power to the drain based on the DC gate voltage, where the second DC power is lower than the first DC power. The MOSFET amplifies the RF input signal based on a third DC power which has a magnitude substantially equal to the difference between the first DC power and the second DC power, and outputs an RF power via the drain. The bypass circuit receives and rectifies the RF power outputted from the drain of the MOSFET, and supplies a recycled DC power resulting from the rectification to the power supply terminal of the RF power amplification unit. [Reference numerals] (32) Power detection unit; (36) RF blocking unit; (52) RF-DC rectification circuit; (54) RF-choke circuit; (61) First load matching unit; (62) Second load matching unit; (70) Power distribution unit; (80) Input matching unit |
