Hu Weidong, Xu Zhihao, Han Zhongde, Jiang Huanyu, Liu Yang, Lu Yuyao, Ligthart Leo P
Opt Express. 2022 Mar 14;30(6):9814-9822. doi: 10.1364/OE.450985.
The terahertz frequency modulated continuous wave (THz FMCW) imaging has proved to be a novel nondestructive testing (NDT) technology for non-metal materials, and the large bandwidth is usually required to meet high range resolution demands in many applications such as multilayer sample under test (SUT). However, broadband THz hardware is difficult to design. In this paper, an ultra-wideband THz FMCW generation method is proposed, which provides frequency modulation bandwidths of up to 386 GHz by time-division multiplexing. Furthermore, an ultra-wideband signal fusion algorithm (USFA) is also proposed and significantly improves the range resolution to 0.46 mm in air. Results from the artificially constructed multilayer structure demonstrate the superiority and effectiveness of our method quantitatively.
太赫兹调频连续波（THz FMCW）成像已被证明是一种用于非金属材料的新型无损检测（NDT）技术，在许多应用中，如多层被测样品（SUT），通常需要大带宽来满足高距离分辨率的要求。然而，宽带太赫兹硬件难以设计。本文提出了一种超宽带太赫兹FMCW生成方法，该方法通过时分复用提供高达386 GHz的调频带宽。此外，还提出了一种超宽带信号融合算法（USFA），并将空气中的距离分辨率显著提高到0.46 mm。人工构建的多层结构的结果定量地证明了我们方法的优越性和有效性。
