数字带阻滤波器

设计方法和上述的设计方法非常相似，设计的时候注意选择合适的函数，同时将 ftype 改为’stop’，注意函数的参数和返回值。由于方法比较相似，这里只选用一种方法来实现带阻滤波器，暂时选择带阻切比雪夫Ⅱ型滤波器。

带阻滤波器的性能指标为：

flp=200 fup=3500 flc=300 fuc=3300 As=46 Ap=3 Fs=22050 -Digital band-stop filter design methods and design of the above-mentioned method is very similar to the design of a time when attention to the selection of a suitable function, at the same time, ' ftype'　changed to ' stop' , the attention of function parameters and return values. As a result of similar methods, only a method of choice to achieve band-stop filter, select the time being Chebyshev band-stop filter Ⅱ. Band-stop filter for the performance indicators: flp = 200　fup = 3500　flc = 300　fuc = 3300　As = 46　Ap = 3　Fs = 22050