Design And Implementation Of Radar Anti-jamming Waveform Based On Jamming Cognition

With the continuous innovation of modern jammer technology,radar is faced with a increasingly complex and changeable electromagnetic environment in actual combat,the current traditional radar anti-jamming technology appears to be more and more weak,and it is difficult to cope with the combat status of the era.In the modern battlefield,the missile-borne radar can guide the missile to carry out high-precision combat strategies such as penetration or target attack,but the missile-borne radar will also be affected by the active suppression jamming and active deception jamming in the process of guiding the missile to fly,which will cause the working efficiency of the radar to decline,the tracking system to be wrong or the target to be lost.Only relying on the radar to passively suppress jamming is not enough to eliminate the influence of jamming,so it is very critical to change the methods and ideas of radar anti-jamming.Therefore,the thesis focuses on the active waveform design method in radar anti-jamming technology,and based on the different characteristic parameters obtained from jamming cognition,the indepth research has been carried out on the design and implementation of anti-jamming waveforms aiming at the distance false target deception jamming,the dense false target forwarding jamming,and the intermittent sampling forwarding jamming faced by missile-borne radar,and a radar anti-jamming waveform library with good effects has been designed and formed.The thesis’ s work is carried out according to the following arrangement:1、Aiming at the distance false target deception jamming,the methods based on parameter agility to suppress pulse compression and the method based on misleading frequency guidance are used to study the design and implementation of anti-jamming radar waveform.By analyzing the characteristics of pulse compression output results of the distance false target deception jamming,the linear frequency modulation signals with orthogonal frequency and slope agility of frequency modulation are designed based on the method of parameter agility,and in order to solve the problem of increasing the total bandwidth of the radar caused by the change of parameters,the linear frequency modulation signal with orthogonal frequency combined with slope agility of frequency modulation is proposed.On this basis,a method based on inter-pulse frequency agility to mislead frequency guidance is proposed,which focuses on the waveform design of the frequency-steering working mechanism of the swept-frequency receiver of the jammer,and affects the working band switching of the jammer through the jump of inter-pulse frequency.2、Aiming at the dense false target forwarding jamming,the method based on radio frequency shielding is used to study the design and implementation of anti-jamming radar waveform.After studying and analyzing the special jamming characteristics of the dense false target forwarding jamming in engineering implementation and the general principle of radio frequency shielding,the waveform timing design criterion of anti-dense false target forwarding jamming based on radio frequency shielding is proposed,and the hardware test experiments in internal field and external field are carried out,and the experimental results further verify its effectiveness.3、Aiming at the intermittent sampling forwarding jamming,the methods based on radio frequency shielding and the method based on intra-pulse frequency orthogonality and segmental pulse pressure are used to study the design and implementation of antijamming radar waveform.Because the intermittent sampling forwarding jamming has similar jamming characteristics to the dense false target forwarding jamming,the antijamming waveform can also be designed by the method of radio frequency shielding,and the anti-jamming effect can also be demonstrated by the experimental results of hardware test.After obtaining the jamming characteristic parameters in advance,the method based on intra-pulse frequency orthogonality is proposed,the transmitted signal is subjected to intra-pulse segmental orthogonality,and the jamming signals are respectively subjected to pulse compression processing and then the jamming effects are compared before and after.