对称较宽通带双工器的直接设计法

Direct design of symmetrical interacting broader bandwidth parallel diplexers

给出了较宽通带对称双工器的直接设计方法。基于同一个低通原型滤波器的两个带宽相同但中心频率不同的带通滤波器 ,根据给出的直接计算公式调整其部分元件值后可直接连接 ,得到性能良好的双工器。

Explicit design formulas are given for symmetrical broader bandwidth parallel diplexers, where the diplexer consists of two bandpass channels connected to a common port, and the two bandpass channels with same band width and operating at different center frequencies are derived from same lowpass prototype. The modified element values of the corresponding lowpass prototypes are expanded as power series in well defined band separation factors separately, and the input admittances of the both channels are expressed as functions of the modified element values. To keep all zero reflection frequencies of the lowpass prototype as corresponding zero reflection frequencies of the corresponding channel, the coefficients for the power series are determined, and the explicit design formulas are given for all modified element values of the lowpass prototypes of the two channels. Meanwhile, additional impedance invertors are used to obtain a parallel realization.