Rotman多波束网络的分析

研究了用于多波束形成网络的微带Ｒｏｔｍａｎ透镜．介绍了基于几何光学法的设计公式，并给出了透镜的相位特性，将透镜的波束口和阵列口等效为二维天线，利用天线理论得到了其幅度特性．并以具有３２个波束口和（或）３２个阵列口的Ｒｏｔｍａｎ透镜为例，分析了偏轴焦距、正轴与偏轴焦距比、波束口数、天线阵单元数、焦角、扫描角及频率等设计参数对透镜性能的影响，为多元Ｒｏｔｍａｎ透镜的设计提供了参考依据．

Analysis of Rotman type multiple beamforming network

Microstrip Rotman lenses which are frequently used in multiple beam forming networks (BFN) are studied. First, the design formulae based on the Geometry Optics are derived and the phase performance is given. Then the beam ports and array ports of the lenses are regarded as 2 dimensional antennas and the amplitude performance is obtained by the antenna theory. The effects of various parameters on the performance of the Rotman lens are predicted. The parameters include off axis focal length, focal ratio, the numbers of beam ports and array ports, focal angle, scan angle and frequency. The resulting curves can be helpful to the design of large electrical size Rotman lens with multiple ports.