u_elipap.m

原名：数字信号处理基础及MATLAB实现,解压缩密码：[e-mail]

function [b,a]=u_elipap(N,Rp,Ar,Omegac);
%未归一化椭圆模拟低通滤波器设计
%b分子多项式系数；a分母多项式系数；
%N为阶数；Ar为阻带波动，As>0；Omegac截止频率，单位为弧度秒
[z,p,k]=ellipap(N,Rp,Ar);
a=real(poly(p));
aNn=a(N+1);
p=p*Omegac;
a=real(poly(p));
aNu=a(N+1);
b=real(poly(z));
M=length(b);
bNn=b(M);
z=z*Omegac;
b=real(poly(z));
bNu=b(M);
k=k*(aNu*bNn)/(aNn*bNu);
b0=k;
B=real(poly(z));
b=k*b;