| CPC H03F 1/0288 (2013.01) [H03F 1/32 (2013.01); H03F 1/56 (2013.01); H03F 3/245 (2013.01); H03F 2200/451 (2013.01)] | 15 Claims |

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13. A power amplifier, comprising:
an input;
a split to apply an input signal from the input to a main amplifier and an auxiliary amplifier;
a passive input network before the input of one of the main and the auxiliary amplifiers to provide a phase shift; wherein the main and auxiliary amplifiers and the output combiner are configured such that at low power levels the auxiliary amplifier is off and the main amplifier sees a large impedance;
at maximum power level both the auxiliary and main amplifiers operate at full power and there is a constant phase shift between them; and
while transitioning from low to maximum power, the systematic AM-AM and AM-PM variations generated by the input phase shift and a load-pulling operation between the main and auxiliary amplifiers via the output combiner combiner compensate for device related distortions that arise from varying voltage swings in transistors of the main and auxiliary amplifiers.
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