| 摘要 |
<p>A feedback loop is composed in which a part of a transmission signal obtained by amplifying a modulation carrier signal by a power amplifier (2) is taken out by a monitor circuit (3), and is detected by an envelope detector (5), and a distortion-free envelope signal delivered from an envelope control signal generator (6) is compared in an error amplifier (7), and by this error signal a gain control terminal (8) of the power amplifier (2) is controlled. The envelope control signal generator (6) possesses a feedback loop which is controlled by a reference voltage (Vref) and a sample hold signal (Sh) to stabilize the mean voltage of a reference envelope signal (Vdetb), and also comprises a multiplier (14) for multiplying Vdetb and a ramping up-down signal (Vramp) to generate a burst-form transmission output. <IMAGE></p> |
