【作者】 张世田；

【导师】 葛德彪；

【作者基本信息】 西安电子科技大学 ， 无线电物理， 2007， 硕士

【摘要】 基于FDTD算法的目标电磁散射特性可视化软件FDTD-XD2.0是集建模、显示、计算于一体的电磁仿真软件。在软件的设计中嵌入了我们课题组自己开发的新方法和技术： 1．根据目标的三角面元数据模型，提出的一种新的FDTD网格自动生成技术。针对三维制作软件，提出了一种基于3DS MAX的FDTD新建模方法，该法可实现FDTD的快速、准确、可视化建模。经过验证对比证明了两种建模方法的可行性。 2．提出了一种基于FDTD方法的双站RCS计算方法，即瞬态场外推时谐场的离散傅立叶变换方法。此法不仅为工程应用提供方便，而且节约了计算时间、提高了计算的精度。运用上述方法，计算了典型目标和复杂目标双站RCS。算例结果表明，本文提出的方法是可行的。 新方法和技术的嵌入极大的提高了仿真软件的整体性能，满足了目标特性散射计算与分析软件的设计技术要求。 此外在目标建模的基础上，通过对比详细的研究，分析了天线罩对导弹散射特性的影响。研究了基于Z变换方法的色散介质电磁散射的三维FDTD方法。将电位移矢量（?）与电场强度（?）之间的频域本构关系变换到Z域。然后利用z^-1算子作为时间延迟因子，将Z域的本构关系转换为时域的本构关系，最后进行时间离散，得到离散时域的电位移矢量（?）与电场强度（?）之间的本构关系，从而得到了三维时域的（?）到（?）、（?）到（?）的FDTD迭代式。并利用此法研究了导弹带有喷焰时的散射特性。更多还原

【Abstract】 Visible software FDTD-XD2.0 based on FDTD arithmetic is a simulation electromagnetic software that can achieve FDTD modeling calculation and three-dimensional show. New methods and new techniques presented by us are applied to soft .They are showed as follows:A novel technique based on file about triangle face-units modeling is presented in this paper. To three-dimensional soft, a visible expeditious and accurate FDTD modeling technique depend on 3DS MAX is studied and applied successfully. By comparing with date, the result show that novel techniques for FDTD modeling are feasible.A novel method for computing object bistatic RCS based on FDTD method is dealt with, namely, the extrapolation result of steady state can be obtained from the FDTD computation of transient state by discrete Fourier transform. For FDTD method, the method can be used for convenience in the engineering application, and save the computing time, and improve its computational precision. The bistatic RCS of a PEC sphere and one complex object are computed, and the numerical results show that the method is feasible.By applying novel techniques and methods, the soft FDTD-XD2.0 is implemented with great.Antenna-radome is simulated accurately by the superspheroid given a specifically numerical value and the backscattering characteristics of it are analyzed in detail. Three-dimensional ZT-FDTD method based on Z transform for electromagnetic scattering by dispersive media is studied. By introducing Z transform, the constitutive relation in Z domain between D|→ and E|→ is derived from its frequency domain expression, the constitutive relation in Z domain is then transformed to time domain via Z transformation. Three-dimensional FDTD iterative formulation from D|→ to E|→ and H|→ to D|→ in time domain can be obtained. The electromagnetic scattering characteristic of a plasma sphere is investigated. The numerical result is in good agreement with the one by using the shift operator method, showing the feasibility of proposed technique. Z transform is used to study scattering of exhaust.更多还原