IFM系统的双交叠信号分析及改进

Analysis of Double Overlapping Signals and Improvement of IFM System

RWR/ESM系统多采用传统的瞬时测频(instantaneous frequency measure,IFM)技术实时检测信号频率,但这种测频技术对交叠信号只能估计一个信号的频率,且容易产生测频错误。现代战场中电磁环境异常复杂,脉冲交叠概率越来越高,因此研究交叠信号对IFM系统的影响尤显重要。为此根据IFM原理,分析了双交叠信号情况下IFM微波鉴相器的各节点响应,并建立了输出UI,UQ的数学模型,提出一种估计双交叠信号频率的算法—UI,UQ推算法。仿真结果表明:该算法能够在保持原有IFM优点的情况下,估计2个交叠信号的频率。

RWR(radar-warning receiver)/ESM(electronic warfare support measure)system usually uses traditional instantaneous frequency measure(IFM)technology to detect the frequency of signals in real time,but it can only estimate one frequency when it receives overlapping signals,and easily create frequency measurement errors.But in complex electromagnetic environment of the modern battle,pulses overlapping probability increase.So analyzing the influence of overlapping signals to IFM system is particularly important.Through the basic principle of IFM,analyzed each node response of IFM microwave phase discriminator in the case of double overlapping signals,built mathematical model of output UI,UQ and put forward a new algorithm—UI,UQcalculation algorithm that can estimate the frequency of double overlapping signals.Simulation results show that the algorithm can estimate the frequency of overlapping signals and keep advantages of original IFM.