At terahertz frequencies, the detailed fine structures on target’s surface can be compared with the wavelength, and the dispersive dielectric property of metals becomes obvious. Then, it is naturally thought that scattering characteristics of metallic spheres will exhibit a special phenomenon when compared with the situation in microwave band or infrared. Thus, a novel method of scattering modeling and calculation is proposed based on a full-wave approach for rough spheres at terahertz frequencies. The influence of the surface roughness and dielectric parameters of metal spheres on the scattering characteristics is evaluated by the proposed calculation method. With the further analyzing, it is clarified that the backscattering characteristics of metallic sphere can be depicted by Rayleigh region, resonant region, optical region, rough attenuation region, scattering enhancement region and ultraviolet transparent region with the increase of frequencies. Both the frequency dispersion and the rough surface decide the scattering characteristics of the metallic sphere, and also determine the frequency positions and amplitude levels of the rough attenuation region and scattering enhancement region.

在太赫兹频率下，目标表面的精细结构可以与波长进行比较，金属的色散介电特性变得明显。那么，很自然地认为金属球体的散射特性与微波波段或红外波段的情况相比会表现出一种特殊的现象。因此，基于太赫兹频率粗糙球体的全波方法，提出了一种新的散射建模和计算方法。通过提出的计算方法评估了金属球的表面粗糙度和介电参数对散射特性的影响。通过进一步分析，明确了金属球的背向散射特性可以用瑞利区、谐振区、光学区、随着频率的增加，粗糙衰减区、散射增强区和紫外透明区。频率色散和粗糙表面都决定了金属球体的散射特性，也决定了粗糙衰减区和散射增强区的频率位置和幅度水平。