u_chb2ap.m

来自「the file contain many matlab signal sour」· M 代码 · 共 26 行

function [b,a]=u_chb2ap(N,As,OmegaC);
% Unnormalized Chebyshev-2 Analog Lowpass Filter Prototype
% --------------------------
% [b,a]=u_chb2ap(N,As,OmegaC);
% b=numerator polynomial coefficients
% a=denominator polynomial coefficients
% N=Order of the Chebyshev-2  Filter 
% As=Stopband Ripple in dB;As>0
% OmegaC=Cutoff frequency in radians/sec
%
[z,p,k]=cheb2ap(N,As);
a=real(poly(p));
aNn=a(N+1);
p=p*OmegaC;
a=real(poly(p));
aNu=a(N+1);
b=real(poly(b));
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=k*b;