- An electric circuit or device which selectively transmits or rejects signals in one or more intervals of frequencies. The transmitted intervals are called passbands, and the rejected intervals are called stopbands. When a filter incorporates active components, such as transistors, it is an active filter, if not, it is passive. A capacitor, for instance, may serve as a passive filter, because it blocks DC. Filters may be classified as falling within one of the following four categories: low-pass, high-pass, bandpass, and bandstop. There are many examples of filters, including comb, ripple, Butterworth, and loop filters. Also called electric filter, electrical-wave filter, or filter (2).
- synonymelectric filter
- synonymelectric-wave filter