一种具有四阶级联结构的IIR数字滤波器的设计

应用虚拟仪器LabVIEW软件设计二级四阶级联型结构的椭圆带通IIR数字滤波器，对它的-3dB带宽、Q值、阻带衰减等主要指标进行测量，并与在相同条件下设计的贝塞尔、巴特沃斯、切比雪夫等其他3种数字滤波器进行性能比较．在此基础上，应用这几种滤波器对一带谐的标准语音主信号进行测试，比较其滤除谐波的效果，得出：椭圆滤波器具有更优越的带通性能．

Design of IIR Digital Filter with Fourth-order Cascade Form

A bandpass elliptic IIR digital filter of two stages with fourth-order cascade form was designed by virtual instrument software LabVIEW. The main technical target of the filter such as - 3 dB passband width, Q value and stopband attenuation were tested and compared with Bessel, Butterworth and Chebyshev filter designed in the same condition. On the basis of these designs, the main frequency with standard har- monic voice signals was tested by using these filters, and the results of harmonic components filtering were compared. It was shown that the elliptical filter had better bandpass performance than Bessel, Butterworth and Chebyshev filter.