Wideband Doherty amplifier circuit with impedance combiner

摘要

An amplifier circuit includes 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 and a third amplifier operable to turn on at all power levels. A first power combiner is 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 is 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. An impedance transformer is 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.