File:Electronic linear filters.svg
Summary
Description |
English: This picture shows the frequency response of all the classic electronic filters of 5th order.
They can be both analog or digital: the output is the same. The first one is the Butterworth filter, that is the smoothest one but it has no ripples. The last one is the Elliptic filter: it is the sharpest one but it shows ripples in both the pass-band and the stop-band. The two Chebyshev filter in the middle have an average behavior, being quite sharp with ripples in part of the spectrum. All the plots have been obtained using the same parameters and the same number of coefficients, thus showing only the properties of the different filters. |
Date | |
Source | Own work |
Author | Alessio Damato |
SVG development | Category:Valid SVG created with Gnuplot code:Charts#Electronic%20linear%20filters.svg ![]() Category:Translation possible - SVGThis plot uses embedded text that can be easily translated using a text editor. |
Source code | Gnuplot code# set the output
set terminal svg enhanced size 1200 960 fname "Times" fsize 25
set output "Electronic_linear_filters.svg"
# axis properties
set xrange [0:1]
set yrange [0:1.1]
set xtics axis
set xtics axis
set key off
# Set up a four-pane multiplot
set size 1,1
set origin 0,0
set multiplot
set title "Butterworth"
set size 0.5,0.5
set origin 0,0.53
plot "electronic_filters.dat" using 1:2 with lines linewidth 3
set title "Chebyshev type 1"
set size 0.5,0.5
set origin 0.5,0.53
plot "electronic_filters.dat" using 1:3 with lines linewidth 3
set title "Chebyshev type 2"
set size 0.5,0.5
set origin 0,0.03
plot "electronic_filters.dat" using 1:4 with lines linewidth 3
set title "Elliptic"
set size 0.5,0.5
set origin 0.5,0.03
plot "electronic_filters.dat" using 1:5 with lines linewidth 3
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This file has been superseded by Filters order5.svg. It is recommended to use the other file. Please note that deleting superseded images requires consent. Reason to use the other file: "The plotlines of this file are jagged. New version with clean plotlines is available." |
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Matlab source code
In order to make it, first I created a file called electronic_filters.dat with the following Matlab code:
% order of the filters
N = 5;
% cut-off normalized frequency
band = 0.5;
% ripple in the pass-band (dB)
Rpass = 0.5;
% ripple in the stop-band (dB)
Rstop = 20;
w = 0:pi/255:pi;
[num, den] = butter(N, band, 'low');
butterfilter = abs(freqz(num, den ,w));
[num, den] = cheby1(N, Rpass, band);
cheby1filter = abs(freqz(num, den ,w));
[num, den] = cheby2(N, Rstop, band);
cheby2filter = abs(freqz(num, den ,w));
[num, den] = ellip(N, Rpass, Rstop, band);
ellipfilter = abs(freqz(num, den ,w));
F = [w/pi ; butterfilter; cheby1filter; cheby2filter; ellipfilter];
F = F';
save -ascii 'electronic_filters.dat' F;
Then I created the plot with Gnuplot
Licensing
I, the copyright holder of this work, hereby publish it under the following licenses:
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Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License. |
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This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. | |
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This licensing tag was added to this file as part of the GFDL licensing update. |
This file is licensed under the Creative Commons Attribution-Share Alike 2.5 Generic, 2.0 Generic and 1.0 Generic license.
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
You may select the license of your choice.
Category:Butterworth filters
Category:CC-BY-SA-2.5,2.0,1.0
Category:CC-BY-SA-3.0-migrated
Category:Chebyshev filters
Category:Elliptic filters
Category:GFDL
Category:License migration redundant
Category:Linear filters
Category:Lowpass transfer curves
Category:Self-published work
Category:Spectrum
Category:Superseded
Category:Translation possible - SVG
Category:Valid SVG created with Gnuplot code:Charts