Method and devices to increase power added efficiency in power amplifiers

Abstract

Methods and devices for improving power added efficiency in multi-stage power amplifiers. The disclosed techniques implement harmonic termination at the driver amplifier while accounting for parasitic elements. The described teachings improve power added efficiency, enhance reliability through reduced peak voltages, and maintain or improve linearity. The techniques are effective at higher operating frequencies and can be applied to both single-ended and differential amplifier architectures. In one embodiment, a multi-stage power amplifier system includes a driver amplifier (DA) stage coupled through an interstage matching network to a power amplifier stage. A DA harmonic termination circuit provides an approximate short circuit at second harmonic frequencies and an approximate open circuit at third harmonic frequencies. The DA harmonic termination circuit includes capacitive and inductive components that work in conjunction with the parasitic output capacitance and series inductance of the DA to increase the overall PAE of the system.

Dependencies are inferred from the claim text.