PML-FDTD及总场散射场区连接边界条件在三维柱坐标系下的实现及应用

Implementation and Application of FDTD and Connection Boundary Conditions of Total-Scattering Fields in 3-D Cylindrical Coordinates

基于直接形式的麦克斯韦方程 ,在三维扩展柱坐标系下推导了完全匹配层吸收边界条件的时域有限差分表达式 (UPML -FDTD) ,将FDTD方法推广到三维柱坐标系中 ,并对其反射系数进行了测试。给出了柱坐标系下完整的总场 -散射场区的连接边界条件以及平面波源的设置方法。最后利用这种方法模拟了平面波在自由空间中的传播过程 ,计算了理想导电圆柱体在TEM波照射下的散射方向图。

Based on un-split Maxwell’s equation, the finite-difference time-domain form is deduced in perfectly matched layer (UPML-FDTD) in three-dimension cylindri cal extended coordinates,and the reflection coefficient of PML is computed. The perfect boundary consistency conditions of total-scattered fields and the metho d to set TEM wave excitation source are proposed in 3-D cylindrical coordinates. At last, the propagation of TEM is simulated and the scattering patterns of a p erfectly electric conductive cylinder are calculated in far zone.