%輸入數(shù)字濾波器的指標(biāo)
clear?all;
wp=0.2*pi;
ws=0.5*pi;
Rp=3;
As=15;
fs=1/2;
%按照預(yù)畸公式換算為模擬指標(biāo)
Wp=2*fs*tan（wp/2）;Ws=2*fs*tan（ws/2）;
%根據(jù)指標(biāo)確定butterworth濾波器的階數(shù)N和3dB截止頻率Omegac??
N=ceil（（log10（（10^