High efficiency amplifier

摘要

An amplifier includes a main amplifier circuit and at least one auxiliary amplifier circuit. Portions of an RF signal to be amplified are delivered to the main and auxiliary amplifiers. The auxiliary amplifier circuit is selectively operable to operate in combination with the main amplifier circuit, such as based on the level of the RF signal. At least one hybrid coupler circuit has input ports coupled with outputs of the main amplifier circuit and auxiliary amplifier circuit. The hybrid coupler circuit is operable to combine amplifier circuit output signals at a coupler first output port. A coupler second output port is terminated with one of an electrical short and an electrical open circuit.