Patent ID: 7944293

Claim:
A power amplification system, comprising: a plurality of power amplifiers configured in parallel, wherein the plurality of power amplifiers receive at least one common input signal, wherein each of the plurality of power amplifiers generates a respective at least one amplified output signal, wherein the respective at least one amplified output signal of each of the plurality of power amplifiers is combined to provide at least one combined amplified signal; and a plurality of adaptive bias circuits corresponding to each of the plurality of power amplifiers for providing a respective adaptive bias signal to the respective power amplifier, wherein at least two of the plurality of adaptive bias circuits have differing bias ranges for the provided respective adaptive bias signals, wherein each of at least two of the plurality of adaptive bias circuits comprise: a differential amplifier that receives differential input signals and generates amplified differential input signals, a current mirror that converts the amplified differential input signals to generate a single-ended signal, a low-pass filter that filters out one or more high-frequency components of the single-ended signal to generate a filtered single-ended signal, and a common-source amplifier or common-emitter amplifier that receives the filtered single-ended signal and generates the respective adaptive bias signal for operating the respective power amplifier.