www.gusucode.com > signal 案例源码程序 matlab代码 > signal/BandpassButterDesignfiltExample.m
%% Bandpass Butterworth Filter % Design a 20th-order Butterworth bandpass filter with a lower cutoff % frequency of 500 Hz and a higher cutoff frequency of 560 Hz. Specify a % sample rate of 1500 Hz. Use the state-space representation. Design an % identical filter using |designfilt|. % Copyright 2015 The MathWorks, Inc. %% [A,B,C,D] = butter(10,[500 560]/750); d = designfilt('bandpassiir','FilterOrder',20, ... 'HalfPowerFrequency1',500,'HalfPowerFrequency2',560, ... 'SampleRate',1500); %% % Convert the state-space representation to second-order sections. % Visualize the frequency responses using |fvtool|. sos = ss2sos(A,B,C,D); fvt = fvtool(sos,d,'Fs',1500); legend(fvt,'butter','designfilt')