Power amplifier with load adjusted in dependence on peak and mean output to control adjacent and alternate channel power

摘要

A power amplifying circuit (300) with load adjust for control of adjacent and alternate channel power. A power amplifier (172) amplifies an input signal to produce an amplified signal. A variable impedance network (174) presents different impedances to the output of the power amplifier (172) responsive to a load control signal. A detector (180) provides an indication of a peak-to-average or difference ratio of the amplified signal. A controller (184) coupled to the detector (180) and the variable impedance network (174) produces the load control signal responsive to the indication of the peak-to-average ratio or difference.