Power amplifier using transmission line transformer

Abstract

Disclosed herein is a power amplifier which is used in a wireless communication system and is capable of improving efficiency in an entire output power range and extending the dynamic range without additional switches, by including a drive amplification unit and a power amplification unit, connecting the drive amplification and the power amplification unit to a matching circuit, and a power coupler included in a transmission line transformer such that the drive amplification unit drives the power amplification unit, or directly outputs power to an output terminal, through the transmission line transformer, that is, the output power of the drive amplification unit is outputted to a load by switching on/off the power amplification unit and the drive amplification unit.