Rotman透镜多波束形成网络的数值分析

Numerical Analysis of Rotman Lens-type Multiple Beam forming Networks

本文利用平板波导模型法与轮廓积分方程法结合分析了一种重要的多波束形成网络—Rotman透镜．首先建立了考虑色散效应的透镜的等效平板波导模型，然后选择适当的波导模式函数展开透镜端口上的场，并利用Galerkin法求解其边缘上电场满足的轮廓积分方程即可得到透镜的多模式散射参数．再根据网络思想，将端口存在的高阶模作为加载。从而得到主模激励的散射参数，计算结果与实验结果吻合得很好．

The analysis of Rotman lens, an important multiple beamforming network is accmplished by the contour integral equation method along with the planar waveguide medol method. First, the planar waveguide models for Roman lensand its feed lines which incorporate the dispersion effect with frequencies are set up. Then the aperture electric fields at lensports are expanded by appropriate waveguide mode functions and substituted into the contour integral equation. The multimode scattering rnatrix of the lens can be acquired by solving the cont0ur integral equation by using Galerkin method. To obtain the scattering matrix corresponding to the dominant mode, higher order modes aroused at lens ports are treated as loads ofthe network. It is proved that the calculated results are in good agreement with the experimental ones.