notch filter

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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.
References in periodicals archive ?
For "Book Page 2", Triangle, Hermite, Quadratic, Cubic B-Spline, Gaussian and Notch filters were constantly the best.
Tenders invited for 532 nm notch filters and band pass filters
The long pass, short pass, and notch filters typically use 100 more layers to form sharp transitions.
Large part of demonstrations focus on well-known NRZ-OOK to pseudo-return to zero (PRZ) format conversion, which could be performed with i) linear methods: fibre Bragg grating (FBG)-based notch filters [8], Fabry-Perot optical band-pass or comb filters [9] or ii) nonlinear methods: using self-phase modulation in a semiconductor optical amplifier [10].
Customers can also choose the optical filters such as IR-pass filters, IR band-pass filters, NIR notch filters etc.
The next advance was the introduction of notch filters, which are designed to reject a pre-selected wavelength band or region while transmitting all other wavelengths within the design range of the filter.
Marques, "Varactor-loaded split ring resonators for tunable notch filters at microwave frequencies," Electron.
Devices used to provide tunable or reconfigurable properties to filter topologies are PIN diodes [17], UWB filters integrated with tunable notch filters using MEMS switches [18] and Tunable notch characteristics by varactor [19].
Special techniques such as notch filters and nulling approaches are needed for measuring tighter specifications.
Notch filters, on the other hand, have the advantage of suppressing only the tremor frequency and reducing distortion of intentional signals [21].
On the output there are harmonics which are reduced with notch filters.
A computer controlled selection of up to four different gratings and notch filters enables the system to be operated by non-expert users.