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Equiripple single-rate FIR filter from specification object


hd = design(d,'equiripple')
hd = design(d,'equiripple',Name,Value)


hd = design(d,'equiripple') designs an equiripple FIR digital filter using the specifications supplied in the object d. Equiripple filter designs minimize the maximum ripple in the passbands and stopbands.

hd = design(d,'equiripple',Name,Value) returns an equiripple FIR filter where you specify design options as Name,Value pairs.

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


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



collapse all

Create a lowpass equiripple filter. Assume the data is sampled at 10 kHz. The passband frequency is 500 Hz and the stopband frequency of 700 Hz. The desired passband ripple is 1 dB with 60 dB of stopband attenuation. Use FVTool to display the magnitude response of the filter.

Fs = 10000;

Hd = fdesign.lowpass('Fp,Fst,Ap,Ast',500,700,1,60,Fs);
d = design(Hd,'equiripple');


Design a lowpass equiripple filter with direct-form transposed structure and a density factor of 20.

df = design(Hd,'equiripple','FilterStructure','dffirt','DensityFactor',20);


See Also



Introduced in R2009a

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