AUTOMATIC ADJUSTMENT TYPE FEEDFORWARD AMPLIFICATION METHOD AND DEVICE THEREFOR

摘要

PURPOSE:To provide the automatic adjustment type feedforward amplification method used over a broad band. CONSTITUTION:This device is provided with a distortion detection circuit 1 detecting a distortion component of a main amplifier 11 and a distortion elimination circuit 2 amplifying the distortion component detected by the distortion detection circuit 1 and adding the amplified component to an output of the main amplifier 11 to cancel the distortion component. A pilot signal for detecting the operating state is injected respectively to the detection circuits and each level of the pilot signal via the detection circuits is detected and the obtained detectionlevel signal is given to a control circuit 29 as a control input to control the detection circuits 1, 2 so that the detection level signals are balanced and smaller thereby eliminating the distortion component generated from the main amplifier 11. In this case, the plural pilot signals apart at an interval of a frequency are respectively injected to the detection circuits and the level of the plural pilot signals via the detection circuits is detected and the control circuit 29 controls the detection circuits so that the detection level signals are balanced and get smaller.