Research On RF Stealth Waveform Design Of Airborne Battlefield Surveillance Radar

With the rapid development of modern radar technology,RF stealth waveform design of airborne battlefield reconnaissance radar plays a vital role in improving the performance of airborne platform in modern warfare.Keeping balance between detection and stealth performance is the key of RF stealth design.Critical intercept distance and Gaussian-KL divergence are proposed as indexes of radar comprehensive performance in this paper.This paper also introduces ambiguity function as a useful tool in waveform design.Firstly,this paper introduces and analyzes the most common signals with ambiguity function to estimate their detection performances.Also,some new system signals such as Chaotic signals and multi-carrier signals are introduced,especially the application of chaos theory and the performance of multi-carrier signals.Secondly,A new signal which combines triangular sweep signal and chaotic-based phase modulation signal is designed for GMTI mode.Ambiguity function shows that the compound signal has lower range peak sidelobe compared with single modulation signals.Also,it is proved that the proposed signal also has good anti-interference ability.Thirdly,this paper introduces multi-carrier signals to achieve large instantaneous bandwidth for Sar mode.Costas frequency coding and phase coding are used to increase frequency agility and waveform complexity.Cyclic complementary P4 code is selected to reduce the peak to average power ratio(PAPR)of multi-carrier signals.The ambiguity function proves that the proposed signal has batter detection performance than single OFDM signals.Finally,this paper introduces joint time-frequency analysis like Wigner-Ville distribution(WVD)and analyzes the RF stealth performance of these proposed signals.Simulation results show that they both have low peak power and their time-frequency distribution are disorderly,which means difficult to recognize and predict.All these simulation results showed that the proposed signals both have better RF stealth ability than single modulation signals.