摘要 |
An amplifier system (120, 820) for radio frequency signals comprises a phase and gain adjuster (122) which receives an input signal and a control vector (C) for producing a distortion-adjusted input signal. The distortion-adjusted input signal is applied to a main amplifier (126) which generates an amplified output signal. A control loop generates a control vector (P) indicative of distortion of the main amplifier. A modified pre-distortion vector generator (199, 899) generates a modified pre-distortion vector (P') which is combined with the control vector to produce a composite control vector (Comp). The composite control vector is applied to the phase and gain adjuster, thereby enabling the phase and gain adjuster to produce the distortion-adjusted input signal. In essence, the modified pre-distortion vector generator performs a vector multiplication (coordinate rotation) of a pre-distortion vector so that the resultant modified pre-distortion vector has a proper direction relative to the control vector.
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