缩比模型的宽频时域太赫兹雷达散射截面(RCS)研究

本文首次以钛宝石飞秒激光振荡级为抽运源,搭建了国内首套宽频时域太赫兹雷达(带宽0.1—1.3 THz)并进行了基于标准球的系统校正验证.利用该雷达测量了太赫兹波段三种缩比模型的散射时域信号.通过改进后的后向投影算法对模型的轮廓外形进行了成像研究,验证了新型时域散射信号成像机理.太赫兹雷达更高的频率,宽谱的特征和高分辨率成像的能力有望用于隐形外形设计过程,成为新兴的太赫兹散射特征研究平台.

Broad-band time domain terahertz radar cross-section research in scale models

Based on terahertz time-domain spectröscopy (THz-TDS) technology, a broad-band time domain terahertz radar system can be used to do research on scattering characteristics of objects. At present, the optical structure and mechanism of this system-showing the radar detection principle and imaging mechanism-has attracted a lot of interest in the terahertz research field. Based on the femtosecond Ti: sapphire osillators pumped terahertz time-domain spectröscopy system, this paper constructs the first terahertz radar system in this country (0.1–1.3 THz). System calibration is carried out by measurements on standard metallic spheres. Three military scale models are measured by the Radar system. The shapes of the models are retrieved by the improved back projection algorithm, which verifies the new imaging mechanism based on time domain scattering signal. With high frequency broad band spectrum and high imaging resolution, the terahertz radar would make great contribution to stealth military units design and become a new research platform on terahertz scattering characteristics.
Keywords： terahertz radar radar cross-section back projection imaging