Study On Effect Of Antenna Cross Polarization On Radar Adaptive Filtering

In the complex and changeable battlefield electromagnetic environment,the radar system's survival condition is deteriorating,bringing significant challenges to the radar system's regular work.Electronic jammers often use variable polarization working mode to interfere with radar's regular operation,weakening the radar's ability to fight electronic interference.This paper considers the problem that the antenna cross-polarization response can cause significant performance degradation to the adaptive filter under the condition of interference polarization change.It shows the causes of performance degradation and presents corresponding adaptive filter design optimization methods.Simulation results show that the proposed optimization methods can reduce the impact of the antenna crosspolarization response and improve the radar system's interference suppression ability under the condition of variable polarization interference.This paper mainly includes the following two parts.1.The impact of the antenna cross-polarization response on adaptive filtering is assessed in section 3.In the presence of variable polarization interference,the antenna cross-polarization response leads to the inconsistency of amplitude and phase errors between array elements,which has a negligible impact on the array adaptive filter as the interference polarization mode is fixed.However,under the condition of variable polarization interference,this inconsistency can be changeable as interference polarization,which causes significant performance degradation to the adaptive filter.This paper first introduces the concept of electromagnetic wave polarization and the basic principles of two typical polarization filters.The spatial filtering array model,beamforming technology,and the widely used sidelobe cancellation technology are introduced next.Finally,the impact of the antenna crosspolarization response on adaptive filtering is assessed by theoretical analysis.2.Adaptive filter design optimization methods are presented in section 4.First,the polarization-sensitive array is introduced,reducing the impact of antenna cross-polarization through its dual polarization-independent receiving channel.Then the adaptive filter design optimization method based on dual-polarization receiving is presented.Second,the polarization parameters of interference can be accurately measured when there is only one interference source.So this paper presents another adaptive filter design optimization method considering polarization disturbance vector.This method can effectively suppress the variable polarization interference.Third,this paper presents an adaptive filter design optimization method based on echo data segmentation for the multi-interference source scenario.By using time-domain segmentation processing,this method reduces the impact of the variable polarization interference.Finally,when the primary antenna is single-polarized,the auxiliary antenna can be designed horizontally-polarized and vertical polarized.This method can effectively improve the performance of sidelobe cancellation under the influence of the cross-polarized antenna.Besides,if the interference polarization is known,an optimization method of sidelobe cancellation based on the prior information of interference polarization mode is proposed.It can lower the computational complexity,storage,and number of interference learning samples.In practice,the impact of antenna crosspolarization response can be reduced or eliminated by choosing an appropriate combination of those methods according to the interference conditions,which can improve adaptive filter performance.