导航接收机跟踪环路电磁干扰的预测方法研究

针对复杂战场电磁环境下，导航接收机因电磁干扰而引起内部卫星跟踪丢失的现象，该文研究了导航接收机跟踪环路在面临带内和带外双频干扰时的效应预测模型。通过对接收机射频前端的阻塞机理分析，以矢量分析的方法推导了射频前端信号的增益公式，并结合接收机跟踪环路相关处理的过程，得到了带外和带内双频干扰下的效应预测模型。之后以载噪比门限值为失锁判据，开展了双频干扰效应试验，试验结果表明上述模型能够对接收机内部卫星跟踪的状态进行预测，预测误差小于±1 dB，且对于窄带和宽带干扰信号同样适用。

Investigation on Prediction Method of Electromagnetic Interference in the Tracking Loop of Navigation Receiver

In view of the phenomenon that the navigation receiver loses tracking of the satellites due to ElectroMagnetic Interference (EMI) in the complex battlefield electromagnetic environment, the effect prediction model of the navigation receiver’ tracking loop, when facing in-band and out-of-band dual-frequency interference is studied. Through the analysis of the blocking mechanism of the receiver’s RF (Radio Frequency) front-end, the gain formula of the RF front-end signal is deduced by the method of vector analysis, and combined with the relevant processing of the receiver, the effect prediction model under out-of-band and in-band dual-frequency interference is obtained. Then, by using the Carrier-to-Noise ratio (C/N₀) threshold as the criterion for loss of lock, a dual-frequency interference effect experiment is carried out. The experiment results show that the above model can predict the state of satellite tracking inside the receiver, whose prediction error is less than ±1 dB, and it is equally applicable to narrowband and wideband interference signals.