图2-2-5三个传递函数的群延迟特性曲线.txt

运用Matlab求解三个传递函数的群延迟特性曲线

%图2-2-5三个传递函数的相位特性曲线

a=[1 -8/15 1/15];
%figure(1);
set(gca,'LineStyleOrder',{'-',':','o'})
b=[1 -3/4 1/8];
[h,w]=freqz(b,a,512,1000);
hold on;							%数字滤波器频响
habs=20*log10(abs(h));
plot(w,unwrap(angle(h)));									%绘幅频特性									%限定轴范围
%figure(2);
b=[1 -9/4 1/2];
[h,w]=freqz(b,a,512,1000);
hold on;							%数字滤波器频响
habs=20*log10(abs(h));
plot(w,unwrap(angle(h)));
%figure(3);
b=[1 -6 8];
[h,w]=freqz(b,a,512,1000);
hold on;							%数字滤波器频响
habs=20*log10(abs(h));
plot(w,unwrap(angle(h)));


%grpdelay
L=128;
a=[1 -8/15 1/15];
figure(1);
set(gca,'LineStyleOrder',{'-',':','o'})
b=[1 -3/4 1/8];
hold on;
[gd,w] = grpdelay(b,a,L);							%数字滤波器频响
plot(w/pi,gd);									%绘幅频特性									%限定轴范围
figure(2);
b=[1 -9/4 1/2];
hold on;							%数字滤波器频响
[gd,w] = grpdelay(b,a,L);							%数字滤波器频响
plot(w/pi,gd);
figure(3);
b=[1 -6 8];
hold on;							%数字滤波器频响
[gd,w] = grpdelay(b,a,L);							%数字滤波器频响
plot(w/pi,gd);