| 摘要 |
<p>A feedback system includes an emitter-follower as a gain stage in the forward path. The emitter-follower has a very wide band width and does not, by itself, effectively narrow the bandwidth of an information channel in which it is used. According to the invention, the feedback system includes a differentiator with a programmable zero in the feedback path. The zero in the feedback path creates a pole in the forward path and the programmed location of the zero influences the pole and controls the bandwidth of the forward path. Using a switch in the feedback path enables the differentiator to be turned off or switched out of the loop so that the forward path is not effected when bandwidth reduction is not required. With appropriate switching, the same differentiator is used to create a zero in the forward path as well as pole in the forward path.</p> |
