A power amplifier circuit (40) that includes an error correction loop (44)
having a lower IP3 error correction amplifier (54) than a main power
amplifier (46) in a main signal path (48). A first attenuator (52) in the
error loop (44) attenuates the RF signal, and provides more attenuation
of intermodulation products in the RF signal and about the same
attenuation for a main frequency of the RF signal for each dB of
attenuation. The error amplifier (54) amplifies the attenuated RF signal
from the first attenuator (52). A second attenuator (56) in the error
loop (44) attenuates the RF signal from the error correction amplifier
(54). A phase shifter (58) phase shifts the RF signal from the second
attenuator (56). A coupler (50) couples the amplified RF signal and the
phase shifted RF signal to cancel out intermodulation products in the
amplified RF signal.