PURPOSE: To obtain a waveform correction device which is capable of giving excellent waveform correction to the nonlinearity of the high frequency signal source by giving an automatic waveform correction in the pulse amplitude modulation of the high frequency signal source.
CONSTITUTION: The output envelope curve of the high frequency signal is detected via envelope curve detector 1, and the waveform data is held temporarily by sample holding circuit 2 in order to eliminate the effect of the loop transient property in the negative feedback system as well as to eliminate the effect of the nonlinearity of the high frequency signal source. The waveform data is then converted into the pulse code through A/D converter 3, and this signal is compared for calculation with the reference waveform memorized in memory circuit 5 through arithmetic process circuit 4. After this, the necessary correction data is converted into the pulse code to be converted into the analog signal through D/A converter 6. And this output signal is controlled as the modulation signal, and thus the waveform correction can be given with every fixed period. As a result, a high-speed and low-distortion rate modulation is possible, thus ensuring a waveform correction highly effective to the nonlinearity of the high frequency signal source.