以超材料为代表的新技术迅速崛起,大大推进了天线罩的技术进步,与往常天线罩不同的是,超材料天线罩改进了天线系统的散射特性。多年来,人们注重于天线罩的传输特性而忽略了散射特性研究,一方面原因是控制天线罩的散射性能的需求不甚迫切,另一方面原因则是准确分析耗时费力,难度很大,特别是电大尺寸的天线罩的散射特性几乎无法精确计算。虽然高频光学近似在分析天线罩传输特性方面,精度较高,基本满足设计需求,但是在分析天线罩散射特性方面,偏差较大,很难满足设计需求。针对超材料天线罩雷达散射特性分析需求,文中首先分析比较了不同方法对于介质天线罩雷达散射截面(RCS)的计算结果的差别,分析了产生的原因,采用特征模型结合全波分析方法,计算了超材料天线罩散射特性,并与测试结果进行了比较,仿真和试验结果的包络符合较好,验证了在天线罩中采取吸收措施能明显降低其RCS,可供超材料天线罩设计师参考。

The rapid rise of new technology represented by meta materials has heavily promoted the radome progress. Different from the usual radome, the meta material radome improves the scattering performance of the array system significantly. For a long time the transmission performances have been attracted attention while the scattering performance neglected instead. The reason is due to that the requirement for the controlling of scattering performance is not urgent on one hand and it is too difficult to conduct accurate analysis at the cost of much effort and time especially for the large electric scale radome. Although the high frequency optics approximation method has fair accuracy in analyzing the transmission performance meeting the requirement of design, there is obvious deviation in analyzing the scattering performance unable to meet the requirement of design. For the requirement of the analysis of meta radome scattering problem, the comparison of computation of dielectrics radome by different method is given and the mechanism is analyzed first and the radar cross section(RCS) of meta radome are then analyzed by using characteristic model combined with full wave method. The simulations are compared with the experiment that shows good agreement in contour. It is also found that the RCS reduction of radome is significant when absorbing structure is applied. It can be provided for meta radome designer as reference.

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