ADI-FDTD+GRT在波导电路分析中的应用

Analysis of Waveguide Circuits Using the ADI-FDTD+GRT Method

本文研究时域有限差分法(FDTD)的一种新的时空压缩技术,并应用于波导电路的分析.首先分析了软激励条件下的改进的几何重置技术(GRT),研究了合理选择源面与参考面的放置位置,使GRT不仅减小了吸收边界对计算结果的影响,而且节省了计算空间,还可以精确得到全部散射参量.另外阐述了与交替方向隐式时域有限差分法(ADI-FDTD)相结合,使计算空间和时间同时被压缩,达到节省计算资源的目的.为了衡量ADI-FDTD+GRT算法的计算精度和效率,分析了包含不连续结构的波导作为算例,将其数值计算结果分别与传统FDTD和HFSS作比较,并将端面和参考面不同间距的ADI-FDTD+GRT与传统ADI-FDTD在仿真结果和资源占用方面进行对比,结果表明本文算法是精确和高效的.

Attention is focused on analysis of waveguide circuits using the ADI-FDTD＋ GRT method to reduce the computational resources required. First,the conventional Geometry Rearrangement Technique （GRT） is modified for the soft source excitation and whole S-parameters can be obtained by locating the source plane and the reference planes correctly.Not only the dominant boundary reflection can be cancelled but also the computational domain can be reduced by the modified GRT. And then the Alternating-Direction Implicit Finite-Difference Time-Domain （ADI-FDTD） method is combined with the modified GRT. By the ADI-FDTD ＋ GRT method the computational time and domain are saved, respectively. In order to demonstrate the computational accuracy and efficiency this method,a waveguide with discontinuous structure is simulated as an example.The numerical results of this method are compared with those obtained by the conventional FDTD method and the HFSS. In addition the numerical results and the computational requirements of the different ADI-FDTD＋ GRT cases are compared with those of the conventional ADI-FDTD method. It is found that this method is accurate and efficient.