针对太赫兹近场散射特性测量特点, 基于CO2激光抽运的太赫兹激光器和双层独立转动平台搭建了一套高频段太赫兹雷达散射截面(RCS)测量系统。利用不锈钢光滑金属球体作为标准定标体验证了系统的可靠性, 测量结果与理论值误差小于3 dBsm, 系统的信噪比优于24 dB。首次利用该系统开展了3.11 THz频点处不同材料及涂覆层圆形金属平板及不同底面直径圆锥体RCS的测量。通过比较分析发现了表面阳极氧化和喷漆处理的航空铝及P304不锈钢与纯航空铝平板的RCS区别, 以及不同底面直径的圆锥体RCS差异, 为太赫兹频段复杂目标体RCS的研究奠定基础。

Considering the terahertz near-field scattering characteristics, a high-frequency terahertz radar cross section(RCS) measurement system was presented based on a CO2 laser pumped terahertz laser and an independent double-deck rotation platform. The reliability of the system was verified by utilizing stainless steel smooth spheres as the standard calibration targets. The error between measurement result and the theoretical value was less than 3 dBsm and the signal-to-noise ratio is better than 24 dB. For the first time, RCS measurement of metal plates was performed with different materials and coatings, and metal cones with different bottom diameter, at a high frequency of 3.11 THz. The RCS difference of pure, anodized, painted aviation aluminum and P304 stainless steel plates, was demonstrated. The RCS of cones with different bottom diameters made of pure aviation aluminum plate was also compared. This work can lay the foundation for further study of the complex target RCS research in the terahertz band.