Abstract: A power amplifier includes a first power transistor configured to amplify a first input radio-frequency (RF) signal and output a first output RF signal; a first transistor comprising a control terminal, a first terminal receiving a first voltage, and a second terminal supplying a first bias current to the first power transistor; a second power transistor configured to amplify a second input RF signal and output a second output RF signal; a second transistor comprising a control terminal, a first terminal receiving a second voltage, and a second terminal supplying a second bias current to the second power transistor; a signal detection circuit configured to detect a first value corresponding to a magnitude of either the first output RF signal or the second output RF signal; and a power supply voltage control circuit configured to adjust the first voltage and/or the second voltage in response to the first value.

Abstract: A power amplifier includes a first power transistor configured to amplify a first input Radio Frequency (RF) signal, and output a first output RF signal; a first bias circuit configured to operate in a first communication mode, and comprising a first transistor configured to supply a first bias current to the first power transistor; and a second bias circuit configured to operate in a second communication mode, and comprising a second transistor configured to supply a second bias current to the first power transistor.

Abstract: A power amplifier includes a first power transistor configured to amplify a first input radio-frequency (RF) signal and output a first output RF signal; a first transistor comprising a control terminal, a first terminal receiving a first voltage, and a second terminal supplying a first bias current to the first power transistor; a second power transistor configured to amplify a second input RF signal and output a second output RF signal; a second transistor comprising a control terminal, a first terminal receiving a second voltage, and a second terminal supplying a second bias current to the second power transistor; a signal detection circuit configured to detect a first value corresponding to a magnitude of either the first output RF signal or the second output RF signal; and a power supply voltage control circuit configured to adjust the first voltage and/or the second voltage in response to the first value.