butter - Butterworth IIR filter design using specification object

Syntax

Description

hd = design(d,'butter') designs a Butterworth IIR digital filter using the specifications supplied in the object d.

hd = design(d,'butter',designoption,value...) returns a Butterworth IIR filter where you specify a design option and value.

To determine the available design options, use designopts with the specification object and the design method as input arguments as shown.

designopts(d,'method')

For complete help about using butter, refer to the command line help system. For example, to get specific information about using butter with d, the specification object, enter the following at the MATLAB prompt.

help(d,'butter')

Examples

Construct a default lowpass filter specification object and design a Butterworth filter:

d = fdesign.lowpass;
hd = design(d,'butter','matchexactly','stopband');

Construct a highpass filter specification object and design a Butterworth filter:

%Order 8 and 3 dB frequency 0.6*pi radians/sample
d = fdesign.highpass('N,F3dB',8,.6);
hd = design(d,'butter');
fvtool(hd)

See Also

cheby1 | cheby2 | ellip

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