cascaded_hp.m

声音过滤器工具大集合.

function [b, a] = cascaded_HP(fc, fs, N)
%CASCADED_HP - Cascaded IIR Butterworth High-Pass Filter Design Routine.
%              Designs an Nth-Order high-pass filter by cascading M second
%              order high-pass sections, where N = 2M.
%
%     usage:  [b, a] = cascaded_HP(fc, fs, N)
%     
%           b = M x three matrix, numerator coefficients
%           a = M x three matrix, denominator coefficients
%          fc = Scalar, cutoff frequency (in Hz)
%          fs = Scalar, sampling frequency (in Hz)
%           N = Scalar, filter order (even)
%           M = Scalar, number of second order sections

%   References:
%      [1]  John Lane, Jayant Datta, Brent Karley, Jay Norwood, "DSP Filters", 
%           PROMPT Publications(an imprint of Sams Technical Publishing), 
%           Indianapolis, IN, 2001, page 146.
%           Book's website: www.dspaudiocookbook.com

%  Copyright (c) 2005 Bo餫