基于Daubechies小波的MRTD在电磁散射中的应用

Application of Daubechies-wavelet-based multiresolution time domain to electromagnetic scattering

研究了时域多分辨分析法,并将其应用于分析目标的电磁散射中,进而说明它的优越性。采用具有紧支撑特性的Daubechies小波作为时域多分辨分析法的展开基函数,系统推导出了该算法严格的计算公式,分析其色散特性和广义完全匹配层吸收边界条件;然后,利用该算法分析介质球体的电磁散射;最后,仿真出该介质球体的二维和三维雷达散射截面,并将所得结果与其他电磁计算方法进行比较。仿真结果表明:在相同精度要求下,时域多分辨分析法不但具有更好的色散特性,而且采用的非均匀网格只有时域有限差分法的一半,计算速度提高了近3倍,计算机的存储空间和内存使用量也相对较少。实验分析表明,该方法在计算目标电磁散射方面也显示出了一定的优势。

The Multiresolution Time Domain （MRTD） is researched and utilized to research the electromagnetic scattering problems for illustrating its superiorities and advantages. By taking the Dau-bechies-wavelet with compact support as the basis, the strict calculation formula was derived to analyze its dispersion characteristic and the absorbing boundary condition of generalized perfectly matchedlayer （GPML）. Then, this algorithm was used to analyze the electromagnetic scattering of a material sphere. Finally, the two-dimension and three-dimension radar scattering sections of the materialsphere were simulated, and the result was compared with those of other electromagnetic algorithms. Comparison results show that MRTD not only has better dispersion characteristic, but also the irregular cells is only half that of Finite Difference Time Domain（FDTD）, and the computing speed can be improved nearly 3 times as compared with the FDTD under the same precision requirement. Mean-while, the utilization of memory and CPU is less. According to the analysis result, MRTD shows a certain superiority in analyzing the electromagnetic scattering problems.