Research On Key Technology Of Signal Processing Of Missile Phased Array Radar

In the complex electromagnetic environment of the battlefield,due to the influence of factors such as multipath environment,coherent target interference,array error and platform motion on the signal echo,traditional beamforming algorithms can hardly make a more accurate estimation of the target azimuth,nor can it adaptively suppress interference.Therefore,robust and adaptive beamforming to multi-coherent targets in complex environments has become an urgently needed technology.Most missile-borne phased array radar array antennas used in precision guided weaponry are arranged in a circular plane,and the current research on array signal processing is mostly based on uniform linear array and uniform area array models.Therefore,research on robust adaptive beamforming methods of circular planar arrays is an inevitable trend of development.First of all,based on the theory of array model of uniform linear array and uniform planar array,a circular planar array model based on two-dimensional uniform planar array model is established.The performances of different array models in the same circular plane are compared via MATLAB simulation.The numerical results indicate that the circular plane array model has lower side lobes and narrower beam width than other array models in beamforming.Secondly,to solve the problem that multiple signal classification algorithm fails to identify multi coherent signal sources,a method based on virtual array interpolation is utilized to transform circular planar array into uniform planar array.Further,two-dimensional forward and backward spatial smoothing is incorporated to decoherence and complete super-resolution direction of arrival(DOA)estimation of multi coherent sources in space.Finally,desired steering vector mismatch caused by the angle estimation error,platform motion and so on is studied.The influences of factors including snapshot,signal to noise ratio(SNR)and angular error on the performance of various one-dimensional robust adaptive beamforming algorithms are taken into account.In this context,an optimal robust adaptive beamforming algorithm is determined and extended to circular plane array.Simulation results show that the revised algorithm based on circular planar array can effectively improve the robustness of beamforming in the presence of directional error.