%% Frequency Response of Quasi-Linear Phase IIR Halfband Decimator
% Create a minimum-order lowpass IIR halfband decimation filter for data sampled at 44.1 kHz. The filter has a transition width of 4.1 kHz, and a stopband attenuation of 80 dB.

IIRHalfbandDecim = dsp.IIRHalfbandDecimator(...
                        'DesignMethod', 'Quasi-linear phase');

%
% Obtain the filter coefficients.

c = coeffs(IIRHalfbandDecim);

%
% Plot the magnitude and phase response.

fvtool(IIRHalfbandDecim,'Analysis','freq')

% Copyright 2012 The MathWorks, Inc.