基于极化分解理论, 分析了金属空间桁架电磁窗的桁杆散射场。针对桁杆截面选型, 对比了圆截面桁杆与矩形截面桁杆的抗弯刚度与电磁散射特性。综合两种截面形状的优缺点, 按照力电性能一体化设计要求, 提出了将二者结合的圆角矩形截面优化设计方案, 并对其辐照效应进行了计算仿真分析。结果表明: 矩形桁杆由于棱边的电荷积聚效应, 相较于圆柱形杆散射场副瓣电平较高, 电磁性能较差, 但抗弯能力更强, 具有更好的保护性; 圆角矩形的散射电平值小于矩形杆, 同时具有超过圆柱形杆的力学特性, 是提高电磁窗力电性能的可行方案。

Based on the polarization decomposition theory, the scattering field of the bar of the metal space frame is analyzed. The mechanical strength and scattering characteristics of the cylindrical bar and the rectangular bar are compared. Considering the advantages and disadvantages of the round bars and the rectangle bars, the optimal design of bars with rounded rectangular section is put forward. The radiation effect are simulated and analyzed. The results show that the rectangle bar has higher sidelobe level than the round bar due to the accumulation of electric charge on its edge, but performs better in resistance of bending. The rounded rectangle bar is a feasible scheme for improving both the mechanics and electromagnetics performance of the radome because of lower scattering intensity and higher mechanical strength.