周期各向异性阻抗劈散射特性

摘要

Plane wave scattering by an infinite wedge whose faces are characterized by the periodic anisotropic impedance is investigated. Based on impedance boundary condition(IBC), an improved hybrid method of the moment method (MM) and the physical optic (PO) is applied to calculate the equivalent electric current on the wedge face. MM-PO method was used to solve scattering problem of PEC wedge and homogeneous anisotropic impedance wadge, researching of the heterogeneous anisotropic impedance wadge mainly focused on the heterogeneity of the transverse direction (perpendicular to the cleft side). Compared to PEC wedge and homogeneous anisotropic impedance wadge, the computation complexity of heterogeneous anisotropic impedance wadge is increasing. A periodic representation of the scattering face is used to prevent the surface effect in the calculated scattering. Several universal series are derived for all elements of the interaction matrix in MM region, and the total current on PO region is the combination of the PO-current and the diffracted current. For MM region,A series of general series was approximate calculated the impedance matrix elements.%研究了平面波照射下无限大周期各向异性阻抗劈散射特性.基于阻抗边界条件(impedance boundary condition,IBC),提出了解决该问题的三维矩量法(MM)-物理光学(PO)混合算法.由于阻抗面的周期性,无穷大劈面上的表面电流可用中心周期单元的电流表示,从而避免计算过程中由于截断而产生的虚假边缘的作用.周期各向异性阻抗劈的劈面划分为MM区和PO区,将劈边附近电流变化剧烈需要精确建模的区域划为MM电流区,而位于MM区外远离劈边缘的区域则为光学电流PO区.MM区阻抗矩阵元素采用通过推导的一系列通用级数来近似计算,PO区通过绕射电流来修正PO电流从而得到PO区总电流.