宽频段太赫兹雷达目标介电参数反演新方法及电磁散射特性研究

The terahertz radar target dielectric properties and electromagnetic scattering characteristics as the basics of radar are different from the infrared and microwave bands with mature theoretical models. This limits the development of basic research in terahertz radars. On this background, we propose to construct a reasonable terahertz interference model to invert non-metal dielectric parameters based on multi-beam interference model. At the same time, we use the causal relationship between dielectric parameters and scattering characteristics, combined with low-frequency end and high-frequency end target scattering experiments. Creating a new metal target scattering model for metal target scattering in the terahertz band. The main contents are as follows: A new theoretical method to achieve dielectric parameters using the multi-beam interference model and Kramers-Kronig (KK) relationship combining with the far-infrared Fourier spectrometer in the wide frequency range from 0.5THz to 7.5THz is proposed. New mechanism model of scattering characteristics research and experimental measurements of the target with different materials, roughness and different size will be carry out to obtain the characteristics of the surface of the terahertz wave scattering properties of rough targets, which explores the scattering characteristics of the transition to the infrared and microwave continuity and consistency of the new Theoretical model. The project has played an important role in promoting the fundamental research of terahertz radar and therefore has important scientific significance and application value.

太赫兹频段雷达目标介电特性及电磁散射特性是雷达研究的基础，其分析方法不同于拥有成熟理论模型的光学及微波波段，限制了太赫兹雷达基础研究的发展。在此背景下，本课题提出基于多光束干涉模型，构建合理的太赫兹波干涉来反演非金属介电参数，同时利用介电参数与散射特性间的因果关系，结合低频端和高频端目标散射实验，建立适应于太赫兹频段新的金属目标散射模型。主要内容包括：提出利用多光束干涉模型和Kramers-Kronig（K-K）关系并结合远红外傅里叶光谱仪反演0.5THz~7.5THz宽频段范围目标介电参数理论新方法；开展不同材料、不同粗糙度及不同尺寸目标体散射特性的新机理模型研究及实验测量，获得太赫兹波在粗糙目标表面的散射特性，探索太赫兹目标散射特性在向红外与微波过渡过程中的连续性和一致性新理论模型，对太赫兹雷达基础研究起到了重要推动作用，因此具有重要的科学意义和应用价值。

太赫兹频段雷达目标介电特性及电磁散射特性是雷达研究的基础，其分析方法不同于拥有成熟理论模型的光学及微波波段，限制了太赫兹雷达基础研究的发展。在此背景下本项目系统开展了理论和实验方面的研究，取得了系列研究成果。. 建立了基于多光束干涉模型，修正了Kramers-Kronig（K-K）高频端指数外推低频端常数外推关系，形成了系统的太赫兹频段金属和非金属目标介电参数反演方法，得到了几种典型目标在0.5THz~7.5THz宽频段范围内的复介电参数、复折射率以及消光系数等光学参数，验证了模型的可靠性，为太赫兹目标散射特性分析奠定理论基础。. 完成搭建高精度太赫兹散射特性测量实验装置，扫描角度分辨率达0.075°，基于该系统开展了不同材料、不同粗糙度及不同尺寸目标体散射特性的实验测量，获得了太赫兹波在粗糙目标表面的散射数据，验证了系统的可靠性，得到了在单频点雷达散射截面的实测数据。对太赫兹雷达基础研究起到了推动作用，具有重要的科学意义和实用价值。