大口径高精度星载天线的热变形优化设计与仿真计算

Thermal Distortion Optimization Design and Simulation of a Large High Precision Satellite Antenna

大口径高精度星载天线在轨运行时,受太阳辐照、进出地影或遮挡影响,会周期性经历各种极端温度环境,导致天线的型面恶化和指向偏差。基于此,进行了某大口径高精度星载天线的热变形优化设计与仿真计算,首先针对高精度天线的结构组成特点,开展热变形影响分析,找出部件变形对天线型面和指向的影响机理。随后,给出了天线型面误差和指向误差的计算方法,研究了天线在轨温度变化情况及温度与热变形的评价关系。通过天线热变形误差敏感性分析,找出了影响天线热变形的关键因素,并在此基础上开展了热变形优化设计。最终的电性能仿真结果显示,在三个特征频率下,天线实际相位中心与理论相位中心偏差很小,均在允许偏差范围内,验证了热变形优化的有效性。

For the influences of solar irradiation,earth shadow and self-shielding,large high precision antenna has to resist extreme thermal environments periodically,which will largely degenerate surface precision and result in pointing error of the signals.Thermal distortion optimization design and simulation of a large high precision satellite antenna is studied.Firstly,structural composition of the antenna is analyzed to find the relationships between part deformations and surface distortion.Also,the calculation processes of surface root mean square and pointing deviation angles are given,and an effective method to evaluate relationships between thermal field and structural distortion is proposed.Then,sensitivity analysis is carried out to determine the key factors of antenna thermal distortion optimization,and the final reflective frequency simulation results show that,phase center of the antenna coincides well with that of the theoretical model,which verifies effectiveness of the optimization work.