Patent attributes
A power amplifier circuit includes a main amplifier circuit having a main amplifier for amplifying an input signal in one of a full-power mode and at least a back-off mode. A first peak amplifier circuit is in parallel with the main amplifier circuit. The first peak amplifier circuit has a peak amplifier in series with a transmission line. The peak amplifier is configured to be activated in the full-power mode and to be de-activated in at least the back-off mode. A combining node is connected to an output of the main amplifier circuit and an output of the transmission line. In some embodiments, a matching network is connected at the output of the combining node. In some embodiments, the transmission line is selected so the first peak amplifier circuit appears substantially as an open circuit to the combining node.