| 摘要 |
An amplifier drive control circuit having a power combiner for combining an RF input signal with a feedback signal to provide a composite RF signal, a power control circuit for providing a selectively attenuated replica of the composite RF signal to the input of the amplifier, and feedback circuitry connected between the output of the amplifier and the power combiner for providing a level controlled portion of the output of the amplifier as the feedback signal. The power control circuit selectively attenuates the replica of the composite RF signal when the power of the composite RF signal exceeds a predetermined threshold, while the feedback circuitry controls the level of the feedback signal as a function of the gain of the amplifier as determined by the level of the composite RF signal and the level of the amplifier output. The feedback circuitry includes a feedback phase control circuit for controlling the phase of the feedback signal relative to the input to the amplifier.
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