Distortion compensation circuit

摘要

A distortion compensation circuit reduces an unbalance between higher and lower 3rd order distortions, the distortions being generated by an amplifier which amplifies an input signal having at least two frequency components. Amplitude modulation means, which includes an amplitude detector, an amplitude circuit, a phase circuit and another amplitude circuit, generates sideband signals corresponding to an instantaneous phase difference between the higher and lower 3rd order distortions, such that distortions generated by the amplifier can be cancelled. Further, sideband signal generating means, which includes an amplitude circuit, a delay circuit, an AM modulator, another amplitude circuit, another delay circuit and a PM modulator, performs AM and PM on the input signal to thereby generate sideband signals, such that distortions generated by the amplifier can be cancelled. <IMAGE>