Cognitive Radar Signal Design And LPI Performance Research

Cognitive radar and LPI radar has been widely applied to modern military combat,because LPI radar can effectively cope with different electromagnetic interference and avoid the radar be found by reconnaissance aircraft of the enemy,so it can improve the survival in military combat. Cognitive radar is a research directioncan of LPI radar,so when the technology of cognitive radar added to the LPI radar, it can improve the performance of LPI radar.Firstly, this paper introduced the development of low cognitive radar and LPI radar,then do the researh of LPI technology exhaustivly,reasoning out of the factor of low probability of intercept and the parameters that impact the low probability of intercept,also discussed some of the theoretical methods to achieve low intercepted,last we analysed a combination of waveform and proposed a new waveform.During the analysis and design of LPI radar waveforms, this paper firstly analysised the basic signal of radar and then introduced the ambiguity function,we can know the LPI performance and detection performance from the ambiguity function. The waveforms that has not been combinated can not meet the requirements of various status,combinated waveforms has advantages of each signal.The bandwidth of Two-phase coding signal is narrow,and the sidelobes of ambiguity function is very low,if we combinate this two signal,so we will get a new signal that has adwantages of each signal,and we can get a verification from the figure of ambiguity function. Finally, this paper presents a new waveform signal,then we give this signal detail analysis about the making process and ambiguity function.We get a very famous figure of ambiguity function,this can say that this signal has good detection performance and anti-jamming performance,such as speed, distance resolution, Doppler sensitivity, anti-noise characteristics, etc.We also use existing time-frequency signal analysis methods to analyse the performance of the new signal,and also verify the better characteristics of the combined signal than other single signal,such as the combinate sigal is harder to be find than single signal.