基于Z变换的高阶完全匹配层实现

基于拉伸坐标完全匹配层(SC-PML)公式和Z变换方法,提出以非分裂场形式来实现具有多极点的高阶完全匹配层的高效算法,来截断时域有限差分(FDTD)网格.在吸收性能方面,高阶PML同时具有传统PML和复频率偏移完全匹配层(CFS-PML)二者的优点.提供的数值算例是二维TE极化电磁波与无限长且有限宽度的理想电导体(PEC)薄片的相互作用.仿真结果显示,高阶PML公式在衰减低频行波和隐失波及减少后期反射方面效果好,比传统SC-PML和复频率偏移的卷积完全匹配层(CPML)算法有更好的吸收性能.

A Z-transform Implementation of Higher-order Perfectly Matched Layer

With stretched coordinate perfectly matched layer(SC-PML) formulations and Z-transform method,an efficient and unsplit-field implementation of higher-order PML scheme with more than one pole is proposed which truncates finite-difference time-domain(FDTD) lattices.The higher-order PML has advantages of both conventional PML and complex frequency shifted PML(CFS-PML) in terms of absorbing performances.A numerical validation of the proposed formulations is provided through a 2D TE-polarized electromagnetic wave interaction with an infinitely long perfectly electric conductor(PEC) sheet with finite width.It is shown that the proposed PML formulations with higher-order scheme are efficient in terms of attenuating low-frequency propagating waves and evanescent waves and reducing late-time reflections.It has better absorbing performances than conventional SC-PML and convolutional PML(CPML) with CFS scheme.