Electric filter

An electric filter as it applies to electrical engineering is a circuit that allows certain frequencies (or frequency bands) to pass unaltered, while other frequencies are dampened. This is applied respective to the frequency to the amplitude and phase so that undesired signal components can be reduced in intensity or even suppressed altogether.

Electric filters can be used at an interference source (interference-emitting equipment) or at an interference sink (equipment affected by the interference) to improve resistance to conducted disturbance.