基于Newmark算法的任意磁化方向铁氧体电磁散射时域有限差分分析

利用坐标系转换矩阵给出实验室坐标系中饱和磁化铁氧体的频域磁导系数张量,再通过频域到时域的转换关系jω→?/?t得到一个二阶微分方程形式的时域本构关系.然后采用Newmark方法求解时域本构关系从而给出一种适用于处理任意磁化方向铁氧体电磁问题的Newmark时域有限差分算法.利用此算法计算了饱和磁化铁氧体层的反(透)射系数和饱和磁化铁氧体球的后向雷达散射截面,所获得的结果验证了此算法的正确有效性.

Newmark algorithm in the finite-difference time-domain analysis of ferrite magnetized in an arbitrary direction

The permeability tensor of saturated magnetized ferrite in frequency domain in the laboratory coordinate system is obtained by using the transformation matrix between the principal and laboratory system. The constitutive relation in time domain, which is a kind of second order differential equation, is derived by employing the transformation from the frequency domain jω to time domain ∂/∂t and solved by utilizing the Newmark algorithm. Consequently, a Newmark finite-difference time-domain method is proposed to deal with the problem of electromagnetic scattering by ferrite which is subjected to an external magnetic field in an arbitrary direction. The electromagnetic scattering by a magnetized ferrite layer and a sphere is simulated, and the numerical results demonstrate the validity and feasibility of the proposed method.
Keywords：Newmark algorithmsaturated magnetized ferriteelectromagnetic scatteringfinite-difference time-domain method