Patent ID: 7425873

Claim:
A radio frequency amplification apparatus including a plurality of radio frequency amplifiers connected to each other, the radio frequency amplification apparatus comprising: an input matching circuit operable to perform matching processing with a pre-stage device; a first-stage amplifier operable to amplify an output from the input matching circuit; an inter-stage matching circuit operable to perform matching Processing with the first-stage amplifier; a final-stage amplifier operable to amplify an output from the inter-stage matching circuit; and a control circuit operable to perform matching processing between the final-stage amplifier and a post-stage device and to feed back an output intermodulation distortion which is output from the final-stage amplifier to the inter-stage matching circuit with a predetermined amplitude and a predetermined phase; wherein the control circuit controls the amplitude and the phase of the output intermodulation distortion such that an intermodulation distortion having a generally invert phase to an intermodulation distortion newly generated by the final-stage amplifier is generated by synthesizing the output intermodulation distortion and an intermodulation distortion generated by the first-stage amplifier, and wherein the control circuit comprises: an output matching circuit operable to perform matching processing between the final-stage amplifier and the post-stage device; an amplitude control circuit operable to control an amplitude of an intermodulation distortion which is output from the output matching circuit by attenuating a desired amount; and a phase control circuit operable to rotate a phase of the intermodulation distortion which is output from the output matching circuit by allowing a desired frequency to pass therethrough.