采用PML吸收边界条件的FDTD法在分析平面微带结构中的应用

Application of the PML Absorbing Boundary Condition to the FDTD Analysis of Planar Microstrip Structures

本文将理想匹配层 ( PML)吸收边界条件用于平面微带结构的时域有限差分法( FDTD)分析中 ,给出平面微带结构的 PML吸收边界条件 ,并编制程序 ,进行数值计算。结果表明 ,与传统的 Mur吸收边界条件相比 ,采用 PML吸收边界条件只需采用最简单的馈源模型就可明显地减小计算网格空间和加快收敛速度 ,并且可用于分析任意复杂结构的微带电路。本文方法对微带电路及微带天线的 CAD设计将具有实际意义。

The perfectly matched layer (PML) absorbing boundary condition (ABC) is used in the FDTD analysis of planar microstrip structures. The PML′ ABC for planar microstrip structures is derived and the numerical experiments are presented. It is shown that the total mesh dimensions can be decreased and the number of time steps required for convergence can be reduced greatly using a simpler feed model compared with Mur′s absorbing boundary condition. Furthermore, this method is valid for arbitrary microstrip geometry. This new technique can be used as a powerful CAD tool in the analysis of planar microstrip circuits and microstrip antennas.