太赫兹低频段随机粗糙金属板散射特性研究

该文提出了一种高效混合近似算法计算太赫兹频段无限薄金属板的电磁散射特性。在太赫兹低频段，金属目标可以被视为具有微粗糙表面的理想导体，散射场可以分为相干场和非相干场。该文采用物理光学法结合截断劈增量长度绕射系数法和微扰法来计算金属板的电磁散射分布。基于蒙特卡洛方法，分别利用多层快速多极子和提出的混合算法计算太赫兹低频段金属板的雷达散射截面，仿真结果表明该文提出的混合算法能够高效快速地给出太赫兹低频段金属板的电磁散射特性。 

Scattering Properties of Electromagnetic Waves from Randomly Oriented Rough Metal Plate in the Lower Terahertz Region

An efficient hybrid algorithm is proposed to analyze the electromagnetic scattering properties of an infinitely thin metal plate in the lower terahertz (THz) frequency region. In this region, the metal plate can be viewed as a perfect electrically conductive object with a marginally rough surface. Hence, the THz scattered field from the metal plate can be divided into coherent and incoherent parts. The physical optics and truncated-wedge incremental-length diffraction coefficients methods are used to compute the coherent part, whereas the small perturbation method is used to compute the incoherent part. Then, the radar cross section of the rough metal plate surface is computed by the multilevel fast multipole and proposed hybrid algorithms. The numerical results show that the proposed algorithm has a good accuracy when rapidly simulating the scattering properties in the lower THz region.