u_buttap.m

来自「the file contain many matlab signal sour」· M 代码 · 共 17 行

function [b,a]=u_buttap(N,Omegac);
% Unnormalized Butterworth Analog Lowpass Filter Prototype
% ----------------------
% [b,a]=u_buttap(N,Omegac);
% b=numerator polynomial coefficients of Ha(s)
% a=denominator polynomial coefficients of Ha(s)
% N=Order of the Butterworth Filter
% Omegac=Cutoff frequency in radians/sec
%
[z,p,k]=buttap(N);
p=p*Omegac;
k=k*Omegac^N;
B=real(poly(z));
b0=k;
b=k*B;
a=real(poly(p));