| 摘要 |
1,045,758. Transistor gain control circuits. RADIO CORPORATION OF AMERICA. Nov. 4, 1963 [Nov. 21, 1962], No. 43507/63. Heading H3T. The tuned output circuit of a gain controlled transistor comprises in series a voltage controlled variable impedance which is controlled such that its impedance varies in the opposite sense to variations in the output impedance of the transistor due to the gain control voltage. As shown, the variable impedance is a biased diode 18 which becomes less conductive as increases in gain control voltage increase the current in the transistor. The diode bias may be such that the impedance variations maintain the bandwidth of the amplifier constant or allow it to widen as the gain is reduced. |
