US Patent 10291185 Doherty power amplifiers with different operating biases

Systems and methods related to linear load modulated power amplifiers. A power amplifier (PA) system can include a divider that splits a signal into two portions, a first portion directed to an attenuator that attenuates the first portion so that the first portion and the second portion have different powers and a second portion directed to a phase shift component that shifts a phase of the second portion so that the first portion and the second portion have different phases. The PA system can also include a Doherty amplifier circuit where a carrier amplifier amplifies the attenuated first portion and a peaking amplifier amplifies the phase-shifted second portion. The carrier amplifier includes a Class AB driver stage and a Class B output. The peaking amplifier includes a Class B driver stage a Class B output stage.