| 摘要 |
PCT No. PCT/JP82/00280 Sec. 371 Date Mar. 21, 1983 Sec. 102(e) Date Mar. 21, 1983 PCT Filed Jul. 20, 1982 PCT Pub. No. WO83/00411 PCT Pub. Date Feb. 3, 1983.An amplitude modulation circuit wherein a resonant circuit for the determination of the carrier-wave frequency is connected to the collector of one transistor forming a differential pair of transistors forming a differential amplifier having its ground terminal connected to a constant current source while an output terminal of the resonant circuit is coupled to the base of the other transistor forming the differential pair so as to apply a positive feedback to the other transistor thereby forming a carrier wave oscillating circuit, and a constant current adjusting means for dividing by switching the current to be supplied to one of the transistors of the differential pair is connected between the differential amplifier and the constant current source, such that, by supplying a modulating signal to the constant current adjusting means to vary the oscillating level of the carrier wave, a modulated signal at a constant modulation degree can be obtained from the base of the other of the transistors forming the differential pair. |
