利用模匹配方法和网络理论分析计算了一种卫星天线系统中常用的波导分支线定向耦合器,计算结果与实验结果非常吻合。该方法为波导分支线定向耦合器提供一种有力的设计手段。它可直接用于设计Ku 波段通信卫星天线的波束形成网络,也可以用来设计各种耦合度的波导分支线定向耦合器。 A modal matching method and network theory are used to analyze and calculate a waveguide branching line directional coupler commonly used in satellite antenna system. The calculated results are in good agreement with the experimental results. This method provides a powerful design tool for waveguide branch-line directional couplers. It can be directly used to design the beam forming network of Ku-band communication satellite antenna, and can also be used to design waveguide branch-line directional coupler with various coupling degrees.