卫星天线极化隔离度在轨测试方法与误差分析

A Measurement Method and Error Analysis for Spacecraft Antenna Polarizing Isolation in Orbit Test

建立卫星天线极化隔离度在轨测试的全程链路模型,分析交叉极化分量产生的机理,给出一种符号表示方法标识由各天线馈源激励产生的各段链路上的信号。分析和实际测试结果表明,主极化和交叉极化接收通道都会在2个相近的频点上产生多个极化分量矢量合成的信号,如果频谱仪分辨率设置不当,则得不到正确的测试结果。由于无法完全分离地面天线和卫星天线产生的交叉极化分量,卫星天线极化隔离度受到地面天线极化隔离度的影响。此外,还描述了高精度测量的卫星天线极化隔离度在轨测试流程和误差分析方法。

A full link model is established to analyze how each cross-polarized component is generated by antennas along the link.A new kind of symbol notation is used to identify signals on each segment of the link.The analysis and test results show that signals generated by each antenna are combined and received at two adjacent frequencies in both co-polarized and cross-polarized channels.Correct test results could not be obtained without right settings of resolution bandwidth of the received spectrum analyzer.Because there is no means to separate the signal generated by ground antenna from that generated by spacecraft antenna,the spacecraft antenna polarizing isolation would be affected by that of the ground antenna.This paper analyzes the error,and whereby a test procedure with high accuracy is described.