提高星载多工器热真空试验测试精度的方法

星载多工器是卫星有效载荷分系统中的关键部件；须对其在热真空环境下的插入损耗、波动等射频性能进行准确测量，以真实反映产品的应用性能。经过分析多工器测试系统原理组成以及导致多工器热真空试验测试数据不准确及不稳定的各项因素，确定测试电缆性能随温度变化是影响多工器热真空试验测试精度的主要因素后，给出5种改进方法，包括：以参考电缆辅助说明测试电缆变化；采用波导阵测试系统；测试电缆实施热控包覆；运用时域分析计算并剔除测试电缆变化；测试电缆多通道实时校准。最后，汇总对比这些改进方法的应用效果，推荐测试电缆多通道实时校准为最佳，为行业提高星载多工器的热真空试验测试精度提供参考。

Methods for improving the measurement accuracy of spaceborne multiplexers in thermal vacuum test

The spaceborne multiplexer is the key component in the satellite payload system. Its RF performance in the vacuum environment, such as the insertion loss and the fluctuations, needs to be accurately measured to evaluate the application characteristics of the component. In this paper, the causes of inaccurate and unstable measurements of the multiplexers in the thermal vacuum test are analyzed based on the configuration and the working principle of the test system, and it is shown that the temperature variation of the test cables is the principal factor affecting the measurement accuracy. Five methods are proposed accordingly to improve the measurement accuracy, including the reference cable assistance check, the introduction of the waveguide test system, the coverage of the test cables for the temperature control, the time domain analysis to offset the performance variation of the test cable, and the real-time channel calibration of the test cables. The actual measurement and calibration are provided. After a balancing among the five methods, we recommend the actual measurement and calibration method, for the industry to improve the multiplexers measurement accuracy in the thermal vacuum test.