一种分析微带交指滤波器的新思路

A New Method for Design of Microstrip Line Interdigital Filter

本文提出一种直接用耦合多导体多介质结构传输特性计算微波滤波器的方法，它不但考虑了相邻导体，也考虑了所有非相邻导体间的耦合，因此计算精度大大提高。此外，它还可以计算不对称耦合，适应面宽。分区均匀介质填充多导体结构有多个不同传播常数的本征模。这与均匀填充多导体结构有很大差别，即不但要考虑本征阻抗，而且要考虑不同的传播常数。本文用矩阵电报方程求出它们的本征值与本征矢量，从而求得传输特性，最后用网络等效方法优化求得滤波器特性。

The paper proposed a numerical method for calculating the characteristic of microwave filter where transmission properties of coupled multi conductor are used directly Not only coupling between adjacent conductor but also non adjacent ones are considered The nonsymmetric coupling structure can be dealt with also So the accuracy of results becomes higher There are many intrinsic modes with different propagation constant in a multiconductor structure filled by many dielectric materials This is quite different from the multiconductor with homogeneous media filled We must consider not only intrinsic impedance but also different propagation constants The intrinsic values and Vectors of Multiconducter transmission line can be got by matrix telegraphist's equation The characteristic of filter can be expressed by equivalent network after optimized The paper presented some examples including a filter with non-equal width cavities structure to show the validity of this method