Phase linearising circuit for travelling wave tube amplifier - has AGC circuit feeding pre-distortion circuit introducing phase distortion

摘要

The phase linearising circuit consists of an automatic gain control (2) and a circuit pre-distorting the phase (4). The gain control circuit contains a modulator/attenuator (8), a modulator (12) a power divider (15) and a detector (10). The pre-distorting circuit contains an amplifier (14), a phase modulator (13) and the detector and the power divider. The gain control circuit passes a signal of constant amplitude to the pre-distorting circuit which produces an output modulated in amplitude and phase. This modulated output is applied to the TWT amplifier and has a distortion opposing that introduced by the nonlinearity of the TWT amplifier.