How to design a Butterworth filter?
9 views (last 30 days)
Show older comments
It is going to be a two-pole low-pass Butterworth filters with a nominal cutoff frequency of 15 Hz.
An additional note is "calculated breakpoint frequencies are 18 Hz and 19 Hz for the first and second pole respectively" not sure if this info is necessary
Yash on 30 Jun 2012
Edited: Walter Roberson on 1 Jul 2012
i developed this code for my program, it may help you
figure % for siren 1
xlabel(' FFT of Siren 1');
n = 1; % Filter order
lf = .5e3; % low frequency cutoff for bandpass
hf = 1.5e3; % high frequency cutoff for bandpass
[b,a] = butter(n, [lf hf]/(fs/2));
fout = filter(b,a,ah);
% Plot Spectrum figure
spec = fft(fout,nfft);
pfspec = spec(1:fix(nfft/2)); % Extract postive frequencies
title('Filter Signal Spectrum ')
Find more on Butterworth in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!Start Hunting!