调频连续波太赫兹雷达方案研究及系统验证

Scheme research and system verification of the terahertz LFMCW radar

太赫兹雷达由于其极高的分辨率而日益受到研究者的重视。该文展示了一种工作在220GHz频段的线性调频连续波体制太赫兹雷达的设计方案和实验结果。该雷达采用超外差结构,以获得更低的相位噪声和更大的动态范围。在雷达发射机基带部分采用了直接数字波形合成技术以获得稳定、快速的线性调频信号频率源,扫频时间40μs,扫频带宽14.4GHz。实验结果表明,解线频调结果与理论分析值相吻合,该雷达非常适合用于高分辨率安检成像和无损检测。

The terahertz radar is getting more and more attention from researchers because of the high resolution it can obtain.The design scheme of a linear frequency-modulated continuous-wave terahertz radar operating at 0.22 THz band is proposed in this paper with the experiment results.Low-noise high dynamic range detection comes from the heterodyne RF architecture of the radar.The transmitter of the radar employs direct digital waveform synthesis technology in the baseband to obtain a reliable fast scanning LFMCW source,the scanning speed of which is 40 μs with instantaneous bandwidth of 14.4 GHz.The result of dechirping is coincided with the theoretical value.The fast scanning speed and wide bandwidth characteristics make the radar an ideal candidate for high-resolution security inspection and non-destructive detection.