Main Content


Cascade of filter system objects



FC = cascade(obj1,obj2,...objn) returns an object, FC, of type dsp.FilterCascade. FC is a cascaded version of the input System objects obj1, obj2,....objn. You can input multiple System objects to the function. The input System objects must be supported by the cascade method. For the list of supported System objects, see Input Arguments.


collapse all

Design a two-stage decimator by cascading dsp.CICDecimator and dsp.CICCompensationDecimator System objects.

Construct the objects

CICDecim = dsp.CICDecimator('DecimationFactor', 6, ...
                            'NumSections', 6);
fs = 16e3;     % Sampling frequency of input of compensation decimator
fPass = 4e3;   % Passband frequency
fStop = 4.5e3; % Stopband frequency
CICCompDecim = dsp.CICCompensationDecimator(CICDecim, ...
                              'DecimationFactor', 2, ...
                              'PassbandFrequency', fPass, ...
                              'StopbandFrequency', fStop, ...
                              'SampleRate', fs);

Create a cascade of the two objects using the cascade method

 FC = cascade(CICDecim, CICCompDecim);

Visualize the frequency response of the cascade

 f = fvtool(CICDecim, CICCompDecim, FC, 'Fs', [fs*6, fs, fs*6],...
        'Arithmetic', 'fixed');
 set(f, 'NormalizeMagnitudeto1', 'on');
 legend(f,'CIC Decimator','CIC Compensation Decimator', ...
             'Overall Response');

Figure Filter Visualization Tool - Magnitude Response (dB) contains an axes and other objects of type uitoolbar, uimenu. The axes with title Magnitude Response (dB) contains 6 objects of type line. These objects represent CIC Decimator: Quantized, CIC Decimator: Reference, CIC Compensation Decimator: Quantized, CIC Compensation Decimator: Reference, Overall Response: Quantized, Overall Response: Reference.

Input Arguments

collapse all

obj1, obj2,....objn are filters to be cascaded. To see the list of System objects you can pass to the cascade method, type

in the MATLAB® command prompt.

Output Arguments

collapse all

Cascaded filter, returned as a System object of type dsp.FilterCascade. For information on the properties of the filter in each stage, type info(FC) in the MATLAB command prompt.

Introduced in R2016a