| 摘要 |
<p>1292560 Active reactances FERNSEH GmbH 25 Aug 1971 [31 Aug 1970] 39862/71 Heading H3R A controllable reactance circuit comprises a cascade transistor circuit having: a coupling network C2, RE between a current feedpoint 2 and a first transistor T1 which phase shifts the current by 90 degrees with respect to the voltage at feedpoint 2; the collector of a second transistor T3 connected to the feedpoint 2; and a control signal applied between the bases of the transistor T3 and a further transistor T2. The tuned circuit LC of an oscillator whose frequency is to be controlled may be connected between feedpoint 2 and earth, or alternatively, Fig. 3 (not shown), between point 2 and the collector of transistor T2. In this alternative form, the phase shift network is connected to the base of T1 instead of to the emitter.</p> |
