notch filter


notch filter

[′näch ‚fil·tər] (electronics) A band-rejection filter that produces a sharp notch in the frequency response curve of a system; used in television transmitters to provide attenuation at the low-frequency end of the channel, to prevent possible interference with the sound carrier of the next lower channel.

Filter, Notch

 

a type of rejection filter. A notch filter is a two-terminal network, usually a parallel resonant circuit, that is inserted into an electric circuit. The impedance of the network increases sharply in a certain relatively narrow frequency band. A notch filter attenuates alternating currents in the particular frequency band and transmits currents at frequencies outside the band.

notch filter

A type of bandstop filter that reduces a narrow range of frequencies. For example, a notch filter in a musical instrument amplifier may reduce frequencies in the range of 59 to 61 Hz, which is sufficient to eliminate any hum coming from the 60 Hz power line. See bandstop filter.