cheby1
Chebyshev Type I filter using specification object
Syntax
chebOneFilter = design(d,'cheby1','SystemObject',true)
chebOneFilter = design(d,'cheby1',designoption,value,designoption,
value,'SystemObject',true)
Description
chebOneFilter = design(d,'cheby1','SystemObject',true) designs
a type I Chebyshev IIR digital filter using the specifications supplied
in the object d. Depending on the filter specification
object, cheby1 may or may not be a valid design.
Use designmethods with the filter
specification object to determine if a Chebyshev type I filter design
is possible.
chebOneFilter = design(d,'cheby1',designoption,value,designoption, returns a type I Chebyshev
IIR filter where you specify design options as input arguments.
value,'SystemObject',true)
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 cheby1, refer
to the command line help system. For example, to get specific information
about using cheby1 with d, the
specification object, enter the following at the MATLAB prompt.
help(d,'cheby1')
Examples
Design a Chebyshev Type I Filter
Construct a default lowpass filter specification object and design a Chebyshev Type I filter.
d = fdesign.lowpass; designopts(d,'cheby1');Use matchexactly option to ensure the performance of the filter in the passband.
LowpassCheb1 = design(d,'cheby1','matchexactly','passband',... 'SystemObject',true);
Use fvtool to view the resulting filter
fvtool(LowpassCheb1)
Construct a highpass filter specification object and design a Chebyshev Type I filter. Specify the filter order, passband edge frequency, and the passband ripple to get the filter exactly as required.
d = fdesign.highpass('n,fp,ap',7,20,.4,50); HighpassCheb1 = design(d,'cheby1','SystemObject',true);
Use fvtool to view the resulting filter
fvtool(HighpassCheb1)
By design, cheby1 returns filters that use second-order sections (SOS). For many applications, and for most fixed-point applications, SOS filters are particularly well-suited.