| 摘要 |
<p>The IF amplifier combines the high frequency and low noise figure characteristics of a cascode stage with the large signal handling capability and accurate gain control of a direct emitter coupled amplifier controlled by a constant current source. The amplifier uses a technique of alternately stacked cascode stages which results in minimizing both the total current drain and the value of DC potential necessary to operate the amplifier. A current mirror, independent of power supply variation, is used to control the gain of the amplifier and is also used to provide temperature compensation for amplifier gain. Special bias techniques along with the current mirror minimize the variation of the amplifier gain with respect to DC power supply variations. Novel use of semiconductor devices minimizes the number of leadout connections on an I.C. chip needed for attaching large external bypass capacitors.</p> |
