首先简要介绍平面魔T的发展历史,指出了MIC和MMIC中魔T设计和分析存在的困难,具体分析了一种由槽线与微带线构成的魔T的物理原理,并给出了详细的等效电路图和计算公式.针对现在微波电路中魔T设计存在的困难,本文提出了将等效电路方法和时域有限差分算法相结合的设计分析方法,随后以这种魔T类型为例,设计了一个用在微波集成电路中的魔T,中心频率为6GHz、带宽为3-9GHz,详述了该方法的整个过程.在应用时域有限差分(FDTD)分析时,为了计算的准确性,采用了PML边界条件和非统一尺寸网格划分(non-uniform grid)方法.

The history of the development of the magic-T in MIC and MMIC is presented briefly,and the difficulty and disadvantage in analysis and design of such magic-T is pointed out.The principle of a model of a magic-T formed by microstriplines and slotlines is explained and detailed equivalent circuits as well as equations based on it are given.To design magic-T effectively,a new method which combine the method of equivalent circuit and FDTD to design magic-T is given.Then an example of designing a magic-T is showed and all process of designing the magic-T in such method is presented in details.This magic-T is similar to one reported by Mzsayishi Aikawa,but is made in MIC and its center frequency is 6GHz.It shows good performance between 3.3GHz to 9.9GHz.The reason for using full-wave analysis is presented.The perfectly matched layer (PML) and non-uniform meshing techniques are used for getting accurate results in analysis by FDTD method.