摘要 |
<p>A filter is disclosed that actively controls one or more filter characteristics, such as the cut-off frequency of a selected filter pole, while minimizing the value of selected filter components such as the capacitor components. This helps improve the performance, reliability and yield of the filter. The filter rejects a selected frequency component or frequency band by actively providing an offset signal that effectively cancels the rejected frequency component or frequency band, while allowing the remaining frequency components or frequency bands to pass relatively freely to the output of the filter. The offset signal may also be used to actively reject a DC offset voltage or current from the input signal.</p> |