| 摘要 |
RF power amplifier (10) distortion is measured in the presence of multi-carrier input signals, by using a common swept local oscillator (117) to tune RF input and output receivers, whose outputs are monitored for distortion correction purposes. In carrier cancellation and feedforward cancellation mode, when the power detected by the input receiver exceeeds a power threshold, the processor (30) accumulates a representation of uncancelled carrier energy detected by the output receiver when sampling the signal at the output of the carrier cancellation combiner. It otherwise accumulates uncancelled IMD sampled at the output of the amplifier downstream of the feedforward cancellation coupler. In predistortion mode, the output receiver monitors only the output of the carrier cancellation combiner. When the power detected by the input receiver does not exceed the threshold, any energy measured by the output receiver corresponds to residual distortion energy which is minimized in the adaptive predistortion control arrangement.
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