aliasingfilter

代码说明：

  1）设计Butterworth型音频抗混叠滤波器； 2）参数： 下通带频率300Hz；上通带频率3400Hz； 下阻带频率280Hz；上阻带频率3600Hz； 通带最大衰减0.3dB； 阻带最小衰减40dB； 3）采用一低通滤波器和一高通滤波器级联； 4）分别确定LPF和HPF的性能指标； 5）求出两滤波器的系统函数和频率响应，并画出其幅频特性曲线； 6）求整个滤波器的系统函数和频率响应，并画出其幅频特性曲线。(1) the design of Butterworth-type audio anti-aliasing filter 2) parameters: passband frequency of 300Hz on pass-band frequency 3400Hz under the stop-band frequency of 280Hz on stop-band frequency 3600Hz passband maximum attenuation of 0.3dB minimum stopband attenuation of 40dB 3) the use of a low-pass filter and a high-pass filter cascade 4) separately to determine the performance of LPF and HPF target 5) to derive two-filter system function and frequency response, and draw its increase frequency characteristic curve 6) for the entire filter system function and frequency response, and draw its amplitude-frequency characteristic curve.)