2020. 2. 12. 05:41ㆍ카테고리 없음
Low Pass Filters Matlab
If you don't have the Control System Toolbox you can do it like that:% some filterb, a = butter(5, 0.6);% Determine frequency responseh, w = freqz(b, a, 2048);% linear approximation of 3 dB cutoff frequencyind = find(abs(h). There is a function in matlab that can give you your cutoff frequency and its called 'freqz'If you already know your filter coefficients 'a' and 'b'. Then freqz provides two variable outputs. One variable stores the complex magnitude gain and the other variable stores the normalized frequencies. Essentially all you would need to do is a run a loop that finds the gain that is closest to your passband gain minus 3dB. Then read off the according index for your frequency variable and you have your answer.