u_chb1ap.m

来自「数字信号处理的matlab实例,数 字信号处理的matlab实例.」· M 代码 · 共 39 行

function [b,a] = u_chb1ap(N,Rp,Omegac);

% Unnormalized Chebyshev-1 Analog Lowpass Filter Prototype

% --------------------------------------------------------

% [b,a] = u_chb1ap(N,Rp,Omegac);

%      b = numerator polynomial coefficients

%      a = denominator polynomial coefficients

%      N = Order of the Elliptic Filter

%     Rp = Passband Ripple in dB; Rp > 0

% Omegac = Cutoff frequency in radians/sec

%

[z,p,k] = cheb1ap(N,Rp);

      a = real(poly(p));

    aNn = a(N+1);

      p = p*Omegac;

      a = real(poly(p));

    aNu = a(N+1);  

      k = k*aNu/aNn;

      b0 = k;

      B = real(poly(z));

      b = k*B;