信号极化方式对跟踪接收机相位影响研究

A Study on the Influence of Signal Polarization on the Phase of Tracking Receiver

移动卫通站大范围机动时可能会出现跟踪接收机相位漂移问题,这与使用的信号极化方式有关,必需采取相应的相位补偿措施才能保持天线的稳定跟踪。以典型卫通地面站天线馈源网络结构为参考,结合圆极化器工作原理,解析了不同状态下各接收端口输出信号的表达式,并根据单通道单脉冲跟踪接收机工作原理及其相位物理含义,全面研究了和、差信号不同极化组合时相位与极化角的关系,据此进行相位补偿,可有效解决地理位置变化引起的跟踪接收机相位漂移问题,并通过多个应用案例进行了验证。最后给出了信号极化方式选择建议,跟踪圆极化卫星时和、差信号极化方式应相同,跟踪线极化卫星时差信号极化方式应保持不变。

When the mobile satcom station moves in a large range,the tracking receiver′s phase drift may occur,which is related to the signal′s polarization mode used.Corresponding phase compensation measures must be taken to keep the stable tracking of the antenna.Based on a typical antenna feed network structure of the satcom earth station and the working principle of the circular polarizer,the expressions of the output signals of each receiving port under different status are analyzed.According to the principle of single-channel monopulse tracking receiver and the physical significance of phase,the relationship between the phase and polarization angle is studied when the sum and difference signals are used in different polarization mode.Phase compensation based on the study can effectively solve the problem of phase drift of tracking receiver caused by geographic position change,which is verified by several application cases.At last,the suggestion of signal polarization mode selection is given,the sum signal′s polarization should be the same as the difference signal’s when tracking a circular polarization satellite,and the polarization mode of the difference signal should be fixed when tracking a linear polarization satellite.