Abstract: In order to improve the Radio Frequency（RF） stealth performance of Low Probability of Intercept（LPI） radar, this paper proposes a method of designing radar waveforms based on chaos theory. Taking use of low probability of being intercepted and fine confidentiality of chaos signal, it chooses logistic map to optimize the traditional frequency modulated signal, which means that it uses chaos sequence to map frequency change of frequency modulated signal. To test the waveform performance, the paper sets up two kinds of evaluation criteria: anti-intercept ability and detecting performance. From theoretical analysis, the Chaos Frequency Modulated Signal（CFMS） can lower interception factor and improve stealth performance. The simulation results show that CFMS is better than other several classical radar waveforms according to ambiguity analysis in detecting performance.

Key words: Radio Frequency（RF） stealth, Low Probability of Intercept（LPI） waveforms, chaos theory, interception factor, ambiguity analysis

摘要： 为提高低截获概率雷达的射频隐身性能，提出了一种基于混沌理论的雷达波形设计方法。利用混沌信号的低截获性和良好的保密性，选取混沌logistic映射对传统调频信号进行优化，即用混沌序列去确定调频信号的频率变化，设计一种混沌调频信号。为验证波形性能，分别从抗截获能力、探测能力两个方面来衡量信号性能。理论分析来看，设计的混沌调频信号具有较大的时宽带宽积，能够较好地降低截获因子以提高隐身性能。仿真表明，在与几种经典的低截获概率雷达波形的性能比较中，该混沌调频信号的模糊函数图更接近“图钉形”，具有更好的测速测距精度。

关键词: 射频隐身, 低截获概率概率雷达波形, 混沌理论, 截获因子, 模糊度分析