一种提高全极化相控阵雷达极化测量精度的方法

An approach to improve the polarization measurement accuracy of fully polarimetric phased array radar

天线交叉极化隔离度与全极化相控阵雷达极化信息精确获取密切相关.为提高交叉极化隔离度,基于三馈点微带贴片天线阵元提出了一种全极化相控阵极化状态配置方法.不同于传统的固定极化状态,如线极化和圆极化,该方法可根据波束指向动态调整辐射信号的极化状态.将交叉极化隔离度提高问题建模成一个多变量带约束非线性最优化问题,从而实现全极化阵元激励幅度和相位的最佳配置.同时,为实现全极化相控阵在极化散射特性测量中的统一化表示,推导了任意极化状态下标准散射体的固有和后向散射矩阵的通用表达式.利用全极化相控阵天线验证了所提极化状态配置方法的有效性和可行性.通过仿真分析,结果表明该方法能够获得更高的交叉极化隔离度,并且能够适应相控阵天线波束宽角扫描特性.经过极化状态配置后的隔离度参数可以显著提高全极化相控阵雷达极化测量精度.

High cross-polarization isolation(CPI)is crucial to the accurate polarization measurement for the fully polarimetric phased array radar(PPAR).In this paper,we propose a polarization state configuration(PSC)method to improve the cross-polarization isolation based on the triple feed microstrip patch element.Compared with the conventional fixed polarization state of radiated wave whether it has linear,circular or elliptical polarization state,our PSC approach configures the polarization state on the basis of beam steering.The CPI improvement is formulated as an optimization problem,thereby achieving the optimum configuration of magnitude and phase for the fully polarimetric antenna.To facilitate the uniform representation for the polarization measurement application of PPAR,the universal expressions of intrinsic and measured backscatter matrices are derived for arbitrary polarization states.The dual-polarization dipole array is used to evaluate the priority of the proposed method.Simulation results reveal that our approach could obtain higher cross-polarization isolation while being available in a larger scanning range.The configured CPI could improve the polarization measurement accuracy for the fully PPAR.