Most of the direction of arrival(DOA) estimation methods often need the exact array manifold, but in actual applications,the gain and phase of the channels are usually inconsistent, which will cause the estimation inv...Most of the direction of arrival(DOA) estimation methods often need the exact array manifold, but in actual applications,the gain and phase of the channels are usually inconsistent, which will cause the estimation invalid. A novel direction finding approach for mixed far-field and near-field signals with gain-phase error array is provided. Based on simplifying the space spectrum function by matrix transformation, DOA of far-field signals is obtained. Consequently, errors of the array are acquired according to the orthogonality of far-field signal subspace and noise subspace.Finally, DOA of near-field signals can be estimated. The method merely needs one-dimensional spectrum searching, so as to improve the computational efficiency on the premise of ensuring a certain accuracy, simulation results manifest the effectiveness of the method.展开更多
The effect of gain-phase perturbations and mutual coupling significantly degrades the performance of digital array radar (DAR). This paper investigates array calibration problems in the scenario where the true locatio...The effect of gain-phase perturbations and mutual coupling significantly degrades the performance of digital array radar (DAR). This paper investigates array calibration problems in the scenario where the true locations of auxiliary sources deviate from nominal values but the angle intervals are known. A practical algorithm is proposed to jointly calibrate gain-phase errors and mutual coupling errors. Firstly, a simplified model of the distortion matrix is developed based on its special structure in uniform linear array (ULA). Then the model is employed to derive the precise locations of the auxiliary sources by one-dimension search. Finally, the least-squares estimation of the distortion matrix is obtained. The algorithm has the potential of achieving considerable improvement in calibration accuracy due to the reduction of unknown parameters. In addition, the algorithm is feasible for practical applications, since it requires only one auxiliary source with the help of rotation platforms. Simulation results demonstrate the validity, robustness and high performance of the proposed algorithm. Experiments were carried out using an S-band DAR test-bed. The results of measured data show that the proposed algorithm is practical and effective in application. (C) 2016 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics.展开更多
如何快速而准确地评估天线阵面结构变形对电性能的影响是工程上亟需解决的关键问题。文中根据某大型相控阵天线设计了3种规格的阵列天线,按照典型的天线阵面碗状变形,分别采用HFSS数值计算方法和有源阵元方向图(Active Element Pattern,...如何快速而准确地评估天线阵面结构变形对电性能的影响是工程上亟需解决的关键问题。文中根据某大型相控阵天线设计了3种规格的阵列天线,按照典型的天线阵面碗状变形,分别采用HFSS数值计算方法和有源阵元方向图(Active Element Pattern, AEP)计算方法计算阵元Z向误差和指向误差对电性能的影响。结果表明:当Z向偏差小于λ/20(λ为波长)时,碗状变形对副瓣电平和波束宽度的影响显著,对增益影响较小;当Z向偏差增大到λ/20时,天线增益明显恶化;随着阵元规模的增大,得益于阵元互耦效应,碗状变形对电性能的影响减弱。AEP计算方法忽略了阵元方向图的差异性及互耦效应,导致其计算精度不如HFSS数值计算方法的计算精度高,特别是副瓣计算结果差异明显。该研究可为相控阵天线结构设计参数的确定提供指导。展开更多
针对阵元幅相误差使波达方向(direction of arrival,DOA)估计精度下降的问题,提出了一种阵元幅相误差和DOA同时估计算法。该算法通过在阵列一侧设置少量已校正阵元,改变了误差矩阵的结构,并根据改变后的矩阵特征构造了变换矩阵,通过构...针对阵元幅相误差使波达方向(direction of arrival,DOA)估计精度下降的问题,提出了一种阵元幅相误差和DOA同时估计算法。该算法通过在阵列一侧设置少量已校正阵元,改变了误差矩阵的结构,并根据改变后的矩阵特征构造了变换矩阵,通过构造的变换矩阵和子空间算法,实现了对阵元幅相误差和DOA的同时估计。此外,该算法能够解决信源功率存在较大差异时误差估计不准的问题,实现了高精度的误差和角度的同时估计。计算机仿真结果证明了所提算法的正确性和有效性。展开更多
基金supported by the National Natural Science Foundation of China(6150117661505050)+5 种基金the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(UNPYSCT-2016017)the Natural Science Foundation of Heilongjiang Province(F2015015)the Outstanding Young Scientist Foundation of Heilongjiang University(JCL201504)the China Postdoctoral Science Foundation(2014M561381)the Postdoctoral Foundation of Heilongjiang Province(LBH-Z14178)the Special Research Funds for the Universities of Heilongjiang Province(HDRCCX-2016Z10)
文摘Most of the direction of arrival(DOA) estimation methods often need the exact array manifold, but in actual applications,the gain and phase of the channels are usually inconsistent, which will cause the estimation invalid. A novel direction finding approach for mixed far-field and near-field signals with gain-phase error array is provided. Based on simplifying the space spectrum function by matrix transformation, DOA of far-field signals is obtained. Consequently, errors of the array are acquired according to the orthogonality of far-field signal subspace and noise subspace.Finally, DOA of near-field signals can be estimated. The method merely needs one-dimensional spectrum searching, so as to improve the computational efficiency on the premise of ensuring a certain accuracy, simulation results manifest the effectiveness of the method.
基金supported by the National Natural Science Foundation of China (No. 61571449)
文摘The effect of gain-phase perturbations and mutual coupling significantly degrades the performance of digital array radar (DAR). This paper investigates array calibration problems in the scenario where the true locations of auxiliary sources deviate from nominal values but the angle intervals are known. A practical algorithm is proposed to jointly calibrate gain-phase errors and mutual coupling errors. Firstly, a simplified model of the distortion matrix is developed based on its special structure in uniform linear array (ULA). Then the model is employed to derive the precise locations of the auxiliary sources by one-dimension search. Finally, the least-squares estimation of the distortion matrix is obtained. The algorithm has the potential of achieving considerable improvement in calibration accuracy due to the reduction of unknown parameters. In addition, the algorithm is feasible for practical applications, since it requires only one auxiliary source with the help of rotation platforms. Simulation results demonstrate the validity, robustness and high performance of the proposed algorithm. Experiments were carried out using an S-band DAR test-bed. The results of measured data show that the proposed algorithm is practical and effective in application. (C) 2016 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics.
文摘如何快速而准确地评估天线阵面结构变形对电性能的影响是工程上亟需解决的关键问题。文中根据某大型相控阵天线设计了3种规格的阵列天线,按照典型的天线阵面碗状变形,分别采用HFSS数值计算方法和有源阵元方向图(Active Element Pattern, AEP)计算方法计算阵元Z向误差和指向误差对电性能的影响。结果表明:当Z向偏差小于λ/20(λ为波长)时,碗状变形对副瓣电平和波束宽度的影响显著,对增益影响较小;当Z向偏差增大到λ/20时,天线增益明显恶化;随着阵元规模的增大,得益于阵元互耦效应,碗状变形对电性能的影响减弱。AEP计算方法忽略了阵元方向图的差异性及互耦效应,导致其计算精度不如HFSS数值计算方法的计算精度高,特别是副瓣计算结果差异明显。该研究可为相控阵天线结构设计参数的确定提供指导。
文摘针对阵元幅相误差使波达方向(direction of arrival,DOA)估计精度下降的问题,提出了一种阵元幅相误差和DOA同时估计算法。该算法通过在阵列一侧设置少量已校正阵元,改变了误差矩阵的结构,并根据改变后的矩阵特征构造了变换矩阵,通过构造的变换矩阵和子空间算法,实现了对阵元幅相误差和DOA的同时估计。此外,该算法能够解决信源功率存在较大差异时误差估计不准的问题,实现了高精度的误差和角度的同时估计。计算机仿真结果证明了所提算法的正确性和有效性。
