Radio frequency amplification apparatus
View Patent ↗An intermodulation distortion which is output from a final-stage amplifier 15 is fed back to an inter-stage matching circuit 14 via a first control circuit 16 and a second control circuit 17 . The first control circuit 16 and the second control circuit 17 control an amplitude and a phase of an intermodulation distortion to be fed back from the final-stage amplifier 15 to the inter-stage matching circuit 14 , such that a synthesized scalar of an intermodulation distortion input from a first-stage amplifier 13 to the final-stage amplifier 15 and amplified by the final-stage amplifier 15 and an intermodulation distortion newly generated by the final-stage amplifier 15 is reduced.
1. 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.
2. 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:
a phase control/matching circuit operable to perform a part of the matching processing between the final-stage amplifier and the post-stage device and to rotate a phase of the output intermodulation distortion which is output from the final-stage amplifier by allowing a desired frequency to pass therethrough;
an output matching circuit operable to perform the remaining part of the matching processing between the final-stage amplifier and the post-stage device; and
an amplitude control circuit operable to control an amplitude of an intermodulation distortion which is output from the phase control/matching circuit by attenuating a desired amount.
3. The radio frequency amplification apparatus according to claim 1 , wherein:
the amplitude control circuit is a series resistor inserted at a feedback path; and
the phase control circuit is a capacitor-inductor-capacitor circuit inserted at the feedback path.
4. The radio frequency amplification apparatus according to claim 1 , wherein:
the phase control circuit is a capacitor-capacitor circuit inserted at a feedback path; and
the amplitude control circuit is a parallel resistor connected between the capacitors.
5. The radio frequency amplification apparatus according to claim 2 , wherein:
the phase control/matching circuit includes a bias line and a parallel capacitor connected in parallel to the output intermodulation distortion which is output from the final-stage amplifier, and a DC cut capacitor inserted in series at a stage post to the parallel capacitor; and
the amplitude control circuit is a series resistor inserted between an output of the DC cut capacitor and the inter-stage matching circuit.
6. The radio frequency amplification apparatus according to claim 2 , wherein:
the phase control/matching circuit includes a bias line and a parallel capacitor connected in parallel to the output intermodulation distortion which is output from the final-stage amplifier; and
the amplitude control circuit is a parallel resistor inserted at a path connected to an output of the parallel capacitor and to a parallel circuit component of the inter-stage matching circuit.