PO-MoM结合近场预条件技术分析复杂载体上线天线辐射特性

提出了一种将近场预条件技术与物理光学-矩量法(PO-MoM)相结合的新技术,并应用于分析电大尺寸复杂载体上线天线的辐射问题.根据PO-MoM方法导出系数矩阵元素的物理意义,忽略PO区的影响,构造出一个稀疏化系数矩阵的近似阵.采用LDU分解和简化的分块Gauss消元算法,快速构造出一个矩阵分解形式的预条件阵.将该预条件阵用于预条件广义最小留数(GMRES)法迭代求解线性方程组,对一个复杂金属载体上的线天线辐射问题进行了分析,验证了此方法的有效性和正确性.在此基础上,计算了一个尺度与真实尺寸相当的舰船模型上超短波天线的远场辐射特性.数值结果表明,采用该技术可以快速有效地分析舰船、飞机等真实移动平台上线天线的辐射特性.

Analysis of radiation behavior of wire antennas mounted on complex platforms by hybrid PO-MoM method in conjunction with near-field preconditioning technique

By combining the near-field preconditioning technique with hybrid physical optics-method of moments (PO-MoM), a novel technique is proposed for analyzing the radiation problems of wire antennas mounted on complex platforms with electrically large size. Based on the physical meaning of the elements in the coefficient matrix deduced from PO-MoM and neglecting the effect of PO-region, a sparse approximate matrix of the coefficient matrix is constructed. Then, a preconditioner with a decomposed matrix form is built easily by LDU (lower-diagonal-upper) decomposition and a simplified blocked Gauss elimination algorithm. The preconditioner is applied to preconditioned generalized minimal residual (GMRES) method to iteratively solve the system of linear equations. The efficiency and exactness of the proposed technique is validated by analyzing a radiation problem of wire antennas mounted on a complex metal platform. Furthermore, the radiation patterns in far field of an ultra-shortwave antenna mounted on a ship model with the comparative size as real ones are calculated. Numerical results show that the technique is suitable for the fast and efficient analysis of radiation behavior of wire antennas mounted on the real mobile platforms of ships, planes, etc.