二维磁等离子体目标FDTD分析的移位算子方法

采用移位算子(SO)方法把时域有限差分(FDTD)法推广应用于二维磁化等离子体中.证明电磁波横向入射二维轴向磁化等离子体目标情形下,电磁波可按目标的轴向分解为横电波(TE波)和横磁波(TM波),而且TM波的散射特性与外磁场无关,而TE波的散射特性与介质电磁参数密切相关,同时对其物理原因进行了分析.采用SO方法处理磁化等离子体频域本构关系,得到该情形下目标电磁散射的SO-FDTD迭代计算公式.计算了轴向磁化等离子体涂敷Von Karm an型导体柱的TE波双站雷达散射截面(RCS),分析了涂层厚度以及等离子体参数对其双站RCS的影响.结果表明,恰当地选择等离子体参数能有效地减少目标在一定散射角范围内的RCS.

Shift operator method applied for the 2-dimensional conducting target coated with magnetized plasma in FDTD analyses

The finite-difference time-domain(FDTD) method is extended to two dimensional anisotropic dielectric dispersive media-magnetized plasma by using Shift Operator(SO). It is proved that when the incident plane wave vector is perpendicular to the axis of the 2-dimensional axial magnetized plasma cylinder, the electromagnetic wave can be decomposed into Transverse Electric(TE) and Transverse Magnetic(TM) waves, with the electromagnetic scattering characters of the TM wave having no relation with the external DC magnetic field but the electromagnetic scattering characters of the TE wave having close relations with the electromagnetic parameters in magnetized plasma. The physical reasons have been analyzed. The FDTD with shift operator (SO-FDTD) formulations in this case is derived based on the constitutive relation for the magnetized plasma and shift operator. For electromagnetic scattering of the Von Karman shaped conducting cylinder coated with anisotropic magnetized plasma, the effect of coating thickness and plasma parameters on the bistatic Radar Cross Section(RCS) is investigated, with some numerical results obtained. The results indicate that appropriate plasma coating may efficiently reduce the RCS of a metallic target.