Patent ID: 8618883

Claim:
A power tracking system for power amplifiers comprising: an N-way Doherty distributed amplifier comprising a power splitter with a plurality of first outputs and N amplifiers, wherein: N is an integer of three or more, the N amplifiers includes a main amplifier and at least two peaking amplifiers, the main amplifier belonging to a different amplifier class than the peaking amplifiers, a first output of the plurality of first outputs is distributed via a first transmission line amongst the a plurality of the peaking amplifiers, each amplifier of the N amplifiers produces a second output, the second outputs from the plurality of peaking amplifiers are combined via a second transmission line to produce a third output, and the third output from the peaking amplifiers is combined with the second output the main amplifier; and adaptive bias supply circuitry that adaptively adjusts a DC bias applied to at least one amplifier of the N amplifiers.