基于八叉树优化的MoM-PO/PTD混合算法分析目标电磁散射及辐射问题

在综合利用矩量法(method of moments, MoM)和物理光学(physical optics, PO)方法的过程中, 要精准识别和划分PO位置处于点光源照射情况下的暗区和亮区。传统的识别划分手段的时间复杂度为O(N²), 当面片数量N增多时, 所需的时间呈现出急剧增长的趋势。文中应用八叉树和后向追踪算法, 对PO亮区判断过程进行加速, 可将时间复杂度由N²降为NlgN。由于计算PO区域电流时没有考虑边缘绕射造成的影响, 导致计算误差较大。鉴于此, 本文在计算过程中引入物理绕射理论对混合算法加以改进, 并通过与FEKO中的MoM相比较, 说明了修正后的混合算法能够有效提升计算精度。

Analysis of electromagnetic scattering and radiation of targets byMoM-PO/PTD hybrid method based on octree optimization

In the process of comprehensively using the method of moments(MoM) and physical optics (PO), it is necessary to accurately judge the lit region and the shadow region where the PO position is illuminated by a point light source. Time complexity of shadowing algorithm based on traditional method is O(N²) where N represents to the patch number of the target which increases sharply with the increase of patch number. In this paper, the computational intensity can be decreased from N² to NlgN by using the octree and backward-ray-tracing accelerating the shadow patches cutting. Since the current in the PO area does not consider the influence of edge diffraction on it, the calculation error is relatively large. Taking into account this, physical diffraction theory is introduced to improve the hybrid method by a modification of the PO current density. Compared with the MoM in FEKO, it shows that the modified hybrid algorithm can effectively improve the calculation accuracy.