幅频算术对称无源带通滤波器的优化设计

Optimization Design of Amplitude-frequency Arithmetic Symmetry Passive Band-pass Filter

为解决无源带通滤波器幅频算术对称问题,提出一种基于极点放置技术的优化设计方法,即在网络综合法设计的滤波器电路基础上,将并臂电感换成串臂电感,在此电感上并联电容增加衰减极点,并利用电路优化技术,使得幅频特性算术对称。实例结果表明,该方法能够使滤波器幅频特性算术对称,而且带内波动小,电路结构简单,阶数少,插入损耗低。

As for the problem of amplitude-frequency arithmetic symmetry, an optimization design method is pro- posed based on pole placement technique. Parallel inductor is transformed to series inductor which is in parallel with capacitor to increase the attenuation pole in the circuit designed by network synthesis method, and amplitude-frequency arithmetic symmetry is realized by circuit optimization technology. The result of simulation indi- cates this method can make the filter amplitude-frequency characteristic arithmetic symmetrical, and the in-band fluctuation is small. Further more, the structure of circuit is simple, the order number is reduced and insertion loss is lower.