星载轻型平板SAR天线热控设计与验证

Thermal control design and validation of a satellite-borne lightweight flat-panel SAR antenna

AS-01卫星搭载的平板SAR天线总的热耗密度可达720 W/m^(2),且天线工作期间,要求有源设备温度处于-20~50℃范围,全阵面温差不超过12℃。针对此要求提出一种以导热均温为主的轻量化热控方案:基于准被动热控设计的原则,选择吸收−发射比η=1.4的阵面热控涂层及多层隔热等措施实现所需目标温度范围;采用导热垫和相变热管双侧导热安装等方式强化天线整体均温导热;针对极端低温工况增加主动热控辅助设计。对SAR天线热控进行仿真分析和全尺寸的热平衡试验,地面验证了各项热控措施的有效性和正确性;最终的在轨飞行表明,天线在轨平均温度10℃左右,T/R模块全阵面温差不超过8.9℃,天线热控在轨工作稳定。

The flat-panel SAR antenna carried by AS-01 satellite has a total heat load density of up to 720 W/m^(2).During the antenna operation,the temperature of the active equipment is required to be in the range of-20℃to 50℃,and the temperature difference of the whole array does not exceed 12℃.In this regard,a lightweight thermal control scheme based on heat conduction and temperature homogenization was proposed.According to the principle of quasi-passive thermal control design,the array thermal control coating with absorption-to-emission ratio ofη=1.4 and multi-layer insulation measures were selected to achieve the desired temperature range.The double-sided installed thermal pads and phase-change heat pipes were applied to enhance the uniform thermal conductivity of the antenna.Active thermal control assistant design for extreme low temperatures was added.Simulation analysis and full-sized thermal balance test on the thermal control were carried out to verify the validity and correctness of the proposed thermal control measures.The final on-orbit flight experiment shows that the average temperature of the antenna is approximately 10℃,and the temperature difference across the whole array of T/R module is not more than 8.9℃,indicating that the antenna’s thermal control system works stably in orbit.