| 摘要 |
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.
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