chap04

说明：  ex4_2 用MATLAB作巴特沃斯低通滤波器设计 ex4_3 用MATLAB作切比雪夫-1型低通滤波器设计 ex4_4 切比雪夫-2型低通滤波器设计 ex4_5 椭圆型低通滤波器设计 ex4_6 传递函数的模拟滤波器数字化 ex4_7 脉冲不变法简单实例 ex4_8 脉冲不变法巴特沃思低通滤波器设计 (ex4_2 using MATLAB for Butterworth low-pass filter design using MATLAB for ex4_3 Chebyshev-1-type low-pass filter design ex4_4 type-2 Chebyshev low-pass filter design ex4_5 elliptic low-pass filter design ex4_6 transfer function digitization of analog filters ex4_7 the same method is simple example of pulse-pulse unchanged law ex4_8 Butterworth low-pass filter design)