基于网络参量的频率响应研究

　　针对传递函数描述的模拟滤波器频率响应具有上凸尖峰的问题，引入微波网络理论，考察插入衰减这一工作特性参量，分析各自的物理意义，比较了传递函数与插入衰减的异同点，并推导了两者的转换关系式。计算和仿真首先由插入衰减得到了标准的滤波器频率响应，利用转换关系式可以从插入衰减得出传递函数的频率响应。结果分析表明，对于模拟滤波器，插入衰减描述其频率响应更准确;而对于数字滤波器，插入衰减和传递函数的概念是一致的，都可以得到标准的频率响应。

　　Abstract:

　　Aiming at the problem that there exists convex peak in the frequency response of analog filter showed by transfer function， the paper introduced microwave network theory，and investigated insert attenuation which is a characteristics parameter. Then the paper compared the similarities and differences between insertion attenuation and transfer function based on the analysis of physical significance of them， and got the conversion relational expression with each other. The paper got the standard frequency response through calculating and emulating insert attenuation, then derived the frequency response of transfer function from the conversion relational expression. The results show that insert attenuation is more accurate to describe the frequency response of analog filter， while insert attenuation and transfer function are accordant to digital filter， both can get the standard frequency response.