PSTD算法及其吸收边界分析

Pseudospectral Time-Domain(PSTD) Algorithm and the Analysis of Its Absorbing Boundary

在解时域电大尺寸电磁场问题时 ,由于受到有限差分格式二阶精度的限制 ,传统FDTD算法的效率很低 ,对内存的要求高 .采用以伪谱方法离散Maxwell微分方程为核心的Pseudospectraltime domain(PSTD)算法计算电大尺寸电磁场时域问题 ,将大大提高计算效率 ,降低内存需求 .本文重点探讨了在PSTD技术中 ,电大尺寸问题的高效实现 ,并和传统FDTD算法进行了比较 .此外还分析了其吸收边界 -完全匹配层 (PML)所发挥的作用 ,PML的设置以及各参数对场吸收的影响 .

Due to limitation of computer's memory and speed, many traditional numerical computational electromagnetic method such as FDTD meets difficulties in solving electrical-large objects problems. A pseudospectral time-domain (PSTD) algorithm is developed recently to overcome limitations in the conventional solution methods for Maxwell's equations. This technique uses the fast Fourier transform (FFT) algorithm for the spatial derivatives and uses the perfectly matched layer (PML) to absorb exocentric wave and eliminate the wraparound effect. Because the Fourier transform has an infinite order of accuracy, only two cells per wavelength are required, compared to 10-16 cells per wavelength required by the FDTD method for the same accuracy. The PSTD algorithm is introduced to solve electrical-large objects problems. A perfectly matched layer (PML) for the absorption of electromagnetic waves in this algorithm is also analyzed.