19、《电路与滤波器相关知识介绍》

《电路与滤波器相关知识介绍》

1. 滤波器设计的Matlab程序

在滤波器设计中，Matlab程序发挥着重要作用。以下是几个关键的Matlab程序：

1.1 optimize.m程序

此程序用于优化图93.7中的二维带通滤波器。具体代码如下：

% Program to optimize for the 2D bandpass filter in Fig. 93.7 
clear all; 
close all; 
order1 = 4; 
order2 = 4; 
pdiv = 15; 
sdiv = 15; 
pts = 20; 
% use a known IIR transfer function for the initial values 
[numz10,denz10] = cheby1(order1/2,0.5,[1/pi 2/pi]); 
[numz20,denz20] = cheby1(order2/2,0.5,[1/pi 2/pi]); 
% convert this transfer function to a form for optimization 
xz0 = []; 
for n = 1:order2+1 
    xz0 = [xz0,numz10*numz20(n)]; 
end 
xz0 = [fliplr(xz0),fliplr(denz10(2:order1+1)),fliplr(denz20(2:order2+1))]; 
xz0 = diasym2(xz0,order1); %xz0 contains the initial values 
% sp