Verfahren und Vorrichtung zum Einstellen eines aktiven Filters

摘要

The invention relates to an adjustable filter (1), in particular for use as an anti-aliasing filter in digital telecommunications networks. For precise tuning to a specific cut-off frequency, said filter comprises adjustable capacitances (3) that determine the frequency response. If several cut-off frequencies are to be adjustable, the inventive active filter (1) comprises a control unit (9) with a measuring device (8) for determining the actual cut-off frequency of the filter (1). Using the actual cut-off frequency of the filter (1) that has been determined and the information concerning the set cut-off frequency to be adjusted, an adjustment rule for the capacitance (3) to be adjusted is selected in a memory device (10). The adjustment rule is used to adjust the capacitance (3) in such a way that the desired set cut-off frequency is obtained and tuning takes place simultaneously to obtain the set cut-off frequency with sufficient precision.