重力作用下天线反射面变形及其调整角度的确定  

Gravity deformation and best rigging angle for surface adjustment of large reflector antennas

作　　者：王伟[1] 段宝岩[1] 马伯渊[1] 

机构地区：[1]西安电子科技大学机电工程学院,陕西西安710071

出　　处：《电波科学学报》2008年第4期645-650,698,共7页Chinese Journal of Radio Science

基　　金：国家自然科学基金(50475171);国家安全重大基础研究计划项目(No.61358)

摘　　要：以结构力学分析为基础,根据最佳吻合抛物面的概念,应用矢量叠加原理推导出了大型天线反射面重力变形随俯仰角变化的数学表达式。针对天线表面精度在某仰角调整好而在另一仰角变差的问题,给出了求解反射面精度最佳调整角的优化计算方法。通过分析某工程12m圆抛物面天线在多工况下的表面误差,及其与ANSYS软件计算结果的比较,证明了所推公式的正确性。数值计算结果表明:此方法能够得到合理的重力预调角。在工程上应用此方法设计和建造大型反射面天线,可提高反射表面的精度,改善天线系统的整体性能。A gravity deformation model was derived by superposition which described the main reflector distortion over the entire range of elevation angles. The corresponding formulae were also deduced based on the analysis of antenna structure. In accordance with convention, the distortion of the antenna surface was considered with respect to the best-fit paraboloid. Reflector surface accuracy decreased due to the gravity contribution to the distortion of the surface. An optimization method was presented to calculate the best rigging angle for reflector surface accuracy. To verify the present equations, a finite element model of 12 m parabolic antenna structure was created and input to the ANSYS program for numerical simulation. The surface distortion under seven elevation angles were computed with comparing the simuation results with ANSYS software method. The data and the figures have demonstrated that the present model is correct and the method is reasonable. Its application in design and construction of large reflector antennas will improve the surface accracy and the whole performance of the antenna.

关 键 词：反射面天线 表面精度 最佳吻合面 最佳调整角 

分 类 号：TN823.27[电子电信—信息与通信工程]