基于菲涅尔区的高频算法

High Frequency Algorithm Using Fresnel Zone

当用物理光学法(PO)计算电大尺寸物体的散射场时,计算负荷非常大。然而利用高频局部化原理,可以大大减少计算量,因为只有部分PO电流对散射场作了有效的贡献。这些作有效贡献的局部化区域分散在散射中心附近,也就是反射点和边缘绕射点附近区域。这些区域可以由菲涅尔区来确定。本文提出了一个在确定菲涅尔区时作几何近似的方法,从而进一步减少计算量,提高计算速度。

For very large surfaces, the computational cost is still very expensive to calculate the scattered fields by the Physical Optics（PO） currents. Due to the locality of the scattered fields, only parts of the PO currents contribute significantly to the scattered field, including the currents near the scattering centers corresponding to the stationary phase points and those near the edge diffraction points. Their distribution areas can be determined using Fresnel zone. This paper proposes a geometry approximation method for deciding the Fresnel zones for a given scatterer and observation point over a large smooth PEC planar surface.