基于Tow-Thomas二阶节的椭圆低通滤波器的设计

针对滤波器的设计问题，为了提高滤波器的性能，方便滤波器的参数调整，简化滤波器的设计过程，提出了基于Tow—Thomas二阶节的椭圆低通滤波器的一种设计方法。根据给定的设计指标，首先利用MATLAB求出满足指标要求的数值传递函数，然后根据Tow-Thomas二阶节的电路结构求出其符号传递函数，再将数值传递函数与符号传递函数进行比较，综合出电路中各元件的计算公式，文中给出了设计实例并进行了PSPICE仿真，结果表明其性能完全能达到设计要求。该方法对任意阶椭圆低通滤波器都实用。

Design of Elliptic Low-pass Filter Based on Tow-Thomas Biquad

In order to improve the filter performances,convenient filter parameter adjustment,simply filter design,a design method for elliptic low-pass filter based on Tow-Thomas biquad is presented.First,a numerical transfer function by MATLAB based on the given specifications is calculated.Second,the symbolic transfer function is evaluated according to the structure of Tow-Thomas circuit.Comparing the coefficients of the two transfer functions,some computing formulations of circuit elements are synthesized.This method is practical for any-order elliptic lowpass filter.A design example of the method is given,and its frequency response is simulated based on Orcad/Pspice10.5.The results show that the performances can completely meet the design requirements.The method is practical for arbitrary order elliptic low-pass filter.