| 摘要 |
<p>An amplitude modulator having first and second differential amplifiers (11, 12) which are commonly supplied with an amplitude modulation carrier signal (fc) and a third differential amplifier (13) which is connected to the emitter current path of the first differential amplifier (11), wherein the third differential amplifier (13) is supplied with a video signal (e'v) for modulation through a limiter and a current value of a current source (20, 30) connected to the third differential amplifier (13) is adjusted to thereby adjust a modulation degree of an amplitude modulated video signal derived from the first and second differential amplifiers (11, 12) so that a white level of an input video signal (ev) can be positively prevented from being deteriorated.</p> |
