风云三号星载天线的准光学分析与设计

利用准光学原理分析了风云三号卫星湿度仪天馈系统. 利用等效面磁流和等效面电流法分析得到栅网在高斯波束入射时交叉极化小于-42 dB. 应用高斯模耦合法代替传统的ABCD矩阵分析偏馈反射面, 在大焦径比情况下, 推导出较为简单的高斯模耦合矩阵解析式. 系统实测方向图与仿真结果对比显示, 准光学分析能够快速处理偏馈反射面天线系统, 得到较高精度的结果. 

Quasi-optical Analysis of FY-3 Satellite Antenna

A Quasi-optical analysis of FY-3 satellite radiometer antenna system is described. Equivalent electrical and magnetic current sheet were used for the analysis of wire grid cross polarization which could be down to -42 dB from the main polarization. A Gaussian coupling method was then introduced to analyze the offset parabolic mirror which was fed by a corrugated horn at 90o. As long as the reflector's f/D is large, the coupling matrix which is used to model the offset effect of the reflector can be derived in a simple way. The simulations and measurements demonstrated that quasi-optical analysis can be applied to offset reflectors well with its efficiency and accuracy.