DISTORTION GENERATING DEVICE

PURPOSE:To compensate the distortion characteristic by forming synthesizingly only a distortion compensation signal from a signal simulating a distortion component with a signal branching an input signal and applying said distortion compensating signal to a power amplifer of milti-stage constitution. CONSTITUTION:The input signal at a terminal 21 is branched by a directional coupler 22, fed to a control circuit 41, branched into two by a distributor 23 of the next stage and fed to a distortion generator 27 via an attenuator 24 and a variable attenuator 28. The distortion generator 27 consists of a distributor 29, amplifiers 30-32, attenuators 33-35, a delay circuit 36, a phase shifter 37 and a synthesizer 38. The signal from the variable attenuator 28 is branched by the distributor 29 and fed to the amplifier 30 and the delay circuit 36. The delay time of the amplifiers 30-32 is compensated by the delay circuit 36 so as to make input signal components fed to the synthesizer 38 opposite to each other, allowing to output the distortion compensatig signal only from the synthesizer 38. The compensating signal is fed to the syntehsizer 26 via a variable attenuator 39 and a variable phase shifter 40, the distortion compensating signal is added to the input signal and the result is inputted to a power amplifier 42.