Patent ID: 8384482
Filing Date: 2013-02-26
Classification: H03F

Abstract:
1. An amplifier circuit, comprising: a first amplifier operable to turn on at a first power level; a second amplifier operable to turn on at a second power level below the first power level; a third amplifier operable to turn on at all power levels; a first power combiner operable to combine an output of the third amplifier with an output of the second amplifier at a first power combining node to form a first combined amplifier output; a second power combiner operable to combine the first combined amplifier output with an output of the first amplifier at a second power combining node to form a second combined amplifier output; and an impedance transformer operable to transform a load impedance of the amplifier circuit to a transformed impedance at the second power combining node, the transformed impedance matching an impedance of the first and second power combiners.