逼近及实现为了避免频率特性对称的限制,必须直接综合带通滤波器,而不是由低通滤波器的电抗变换来设计带通滤波器。直接综合带通滤波器的方法曾被 Cauer,Scowen,Saal 和 Ulbrich 简单地叙述过,而近年来被渡部和作了较详细的讨论。本文对 Scowen 根据参考滤波器来综合带通滤波器的方法作一些补充说明及一些推广。这里使用的符号和 Cauer 书中一致。 Approximation and Implementation In order to avoid the limitation of the symmetry of the frequency characteristic, the band-pass filter must be directly integrated with the band-pass filter rather than the low-pass filter. The direct synthesis of band-pass filters has been briefly described by Cauer, Scowen, Saal and Ulbrich, and has been discussed in more detail by Watanabe in recent years. In this paper, Scowen based on the reference filter to integrate band-pass filter method for some additional explanation and some promotion. The symbols used here are the same as Cauer’s book.