椭圆滤波器边带优化设计方法研究

An Approach for Optimizing Band-edge Characteristics of Elliptic Function Filters

给出了椭圆函数滤波器边带特性优化设计的一种新方法。该方法把椭圆函数滤波器的边带选择性作为一个设计参数进行优化处理,充分利用函数逼近阶数的计算余量,通过相应的算法调整归一化的阻带角频率使边带选择特性最大化,可以在不增加阶数的前提下获得更好的衰减特性,有效地减小过渡带宽。文中给出了计算方法和实例分析。

A novel design method for optimizing band-edge characteristic of elliptic function filters is presented.The proposed technique precisely controls band-edge selectivity of elliptic function filters as a variable free parameter.The optimum value is obtained by minimizing the residue order of approach function with some given additional calculation steps to adjust stop-band corner frequency.That allows designer to maximize the band-edge selectivity of elliptic filters.And the better attenuation characteristic of band-edge can be obtained to effectively narrow transition band width without increasing filter order.Theory analysis,realization algorithm and design example of the method are given and described .