脉间复合调频脉内相位编码雷达信号设计与分析

To solve the complex modulation problem of the radar radio frequency (RF) stealth waveform design, a hybrid strategy of interpulse compound frequency modulation and intrapulse polyphase modulation is proposed. The nonlinear frequency modulation characteristic was used to modulate the interpulse constant frequency of Costas signal, and the polyphase codes were used to modulate the intrapulse phase of the hybrid signal, and then the IPNC-PC signal (interpulse hybrid frequency modulation and intrapulse polyphase-coded signal) was obtained. The interpulse compound frequency modulation increases the time-frequency complexity, and the intrapulse polyphase modulation increases the phase randomness. Simulations show that the IPNC-PC signal has the "thumbtack" ambiguity function, the level of autocorrelation sidelobe is -41 dB, the narrowing rate of the mainlobe width is 39% at most, and the power spectrum density (PSD) peak is lower than -10 dB. Therefore, it can be concluded that the IPNC-PC signal features a low intercept and better RF stealth performance and thus has a good application prospect in modern electronic warfare.