The document discusses the design of a notch filter with a central frequency of 3.1206 kHz, detailing its function as a band-stop filter that attenuates specific frequencies while allowing others to pass. It describes applications of narrow notch filters in various audio and electronic systems, emphasizing their role in preventing feedback without affecting the overall frequency spectrum. The results of the notch filter design are provided, indicating successful simulation using OrCAD.

1. Topic: To design a
Notch filter having
central frequency
3.1206 KHz
Submitted by:-
Sushil Kumar Mishra
ECE-I
05311502809
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2. Introduction:
In signal processing, a band-stop filter or band-rejection filter is
a filter that passes most frequencies unaltered, but attenuates those in
a specific range to very low levels. It is the opposite of a band-pass fil-
ter. A notch filter is a band-stop filter with a narrow stopband (high Q
factor).
Narrow notch filters (optical) are used in Raman spectroscopy, live
sound reproduction (public address systems, or PA systems) and
in instrument amplifiers (especially amplifiers or preamplifiers for acous-
tic instruments such as acoustic guitar, mandolin, bass instrument am-
plifier, etc.) to reduce or prevent audio feedback, while having little no-
ticeable effect on the rest of the frequency spectrum
(electronic or software filters). Other names include 'band limit filter', 'T-
notch filter', 'band-elimination filter', and 'band-reject filter'.
Typically, the width of the stopband is 1 to 2 decades (that is, the high-
est frequency attenuated is 10 to 100 times the lowest frequency atten-
uated). However, in the audioband, a notch filter has high and low fre-
quencies that may be only semitones apart.
Fig.1 A generic ideal band-stop filter, showing both positive and nega-
tive angular frequencies
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3. Circuit diagram snapshots:
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4. 4

5. 5

6. Simulation output:
Result : Notch filter having central frequency 3.1206 KHz has
been made on orcad and simulated. Trace has been taken.
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