Patent ID: 7912160

Claim:
A modulation circuit comprising: a modulator modulating a received signal and outputting a modulated signal; a detector circuit receiving the modulated signal and outputting an envelope of the modulated signal; a first controller regulating an offset level of the modulator based on the envelope; and a second controller regulating gain of the modulated signal based on the envelope, wherein the first controller regulates the offset level based on first and second amplitudes of the envelope, the first amplitude being with regard to a maximum amplitude of the envelope, the second amplitude being with regard to a minimum amplitude of the envelope, the first controller compares the first and second amplitudes and regulates the offset level based on a result of comparing the first and second amplitudes, the first controller regulates the offset level for equalizing the first amplitude and the second amplitude, and the second controller regulates the gain after the first controller finished regulating the offset level.