HIGH-FREQUENCY POWER AMPLIFIER

摘要

There is a need to provide a high-frequency power amplifier capable of reducing a talk current and reducing a phase deviation in output. The high-frequency power amplifier includes differently sized first through fifth power amplification transistors and impedance matching circuits for example. The high-frequency power amplifier changes a signal path to be used in accordance with a power specification signal. The high-frequency power amplifier uses a signal path from the first transistor to the second transistor in high power mode. The high-frequency power amplifier uses a signal path from the first transistor to the third transistor in medium power mode. The high-frequency power amplifier uses a signal path from the fourth transistor to the fifth transistor in low power mode. The high-frequency power amplifier is configured so that each of the signal paths includes the same number of stages of power amplification transistors and impedance matching circuits.