Study On DOA And Polarization Parameter Estimation Based On Dual Polarization Conformal Array

Conformal array antenna is an array antenna attached to the surface of the carrier,which has the advantages of low radar cross section(RCS),strong concealment,and large beam scanning range,so it has been widely applied in many fields.The conformal array has a complicated structure,and the pattern and polarization characteristics of each antenna element are different.Therefore,most direction of arrival(DOA)methods for traditional planar arrays are no longer applied to conformal arrays.The two feed points of the dual polarized antenna excite and receive their polarization components independently.Compared with the traditional conformal array,it has stronger polarization information processing ability.Therefore,the DOA and polarization parameter estimation based on the dual polarized conformal array have important research significance.In this dissertation,the DOA and polarization parameter estimation of dual-polarized conformal arrays are studied.The main contents of the paper are as follows:Firstly,the thesis analyzes and constructs the signal model of the dual polarized conformal array based on the planar array model.Secondly,a dual polarized multiple signal classification(DP-MUSIC)method is presented based on the dual polarized conformal array.Each polarization signal is decomposed into two orthogonal polarization components,which are considered to be a pair of coherent signals coming from different polarizations in the same direction.The polarization parameters are modeled as the equivalent coherence coefficients of the orthogonal polarization components.Then,the method of decoherence can be used to decouple the information of polarization states and signal angles.After that,the DOA and polarization parameters can be estimated by the DP-MUSIC algorithm.Moreover,the angles of incident direction are re-estimated,which greatly improves the accuracy of DOA estimation.Finally,a space-polarization domain multi-beam parameter estimation algorithm is proposed based on dual polarized conformal array.The dual polarized conformal array has strong polarization information processing ability,and can form a multi-beam covering the space domain and the polarization domain.The multi-beam contain angle and polarization information,and each beam only receives signal of a certain angle and polarization state.Therefore,the signals of different angles and polarization states havedifferent response distributions to these beams,and this characteristic can be used for the DOA and polarization parameter estimation.In this algorithm,the estimation process of the DOA and polarization parameters of the incoming signal is not related to each other,and they can be estimated simultaneously.