<p>A linear transmitter which controls a bias voltage of the drain electrode or the collector electrode of a high-frequency amplifier based on an envelope of modulated waves, wherein the envelope is formed by using in-phase envelope components and orthogonal envelope components obtained from the base band signals; and the bias voltage of the high-frequency amplifier is controlled by the processing of digital operation. @(65pp Dwg.No.1/43)@.</p>
