使用亚太赫兹自注入锁定调频雷达的超分辨率测距
Super-resolution ranging using a sub-terahertz self-injection-locked frequency-modulated radar
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中文总结 AI 辅助
该研究提出采用自注入锁定机制的亚太赫兹全集成自混频调频雷达，克服电子FMCW雷达带宽与相位噪声问题，实现亚毫米级测距分辨率及<0.002%的距离精度，可用于带微米特征的覆盖印刷字母成像。
中文摘要 AI 辅助
亚太赫兹（sub-THz）和太赫兹（THz）调频连续波（FMCW）雷达已开辟了众多科学与工业应用，尤其在成像领域。尽管亚太赫兹/太赫兹FMCW雷达成像的有力候选方案采用光子学方法实现，但人们期望获得仅电子学才能提供的完全集成度与便携性。然而，集成电子亚太赫兹/太赫兹FMCW雷达的带宽（<100 GHz）远低于基于光子学的雷达，将雷达的距离分辨率限制在毫米级（>1.5 mm）。此外，电子FMCW雷达的宽带宽伴随发射机相位噪声增大，进而降低雷达的距离精度。本文提出一种采用自注入锁定（SIL）机制的亚太赫兹全集成自混频调频（AFM）雷达，从根本上克服FMCW雷达的上述挑战。该AFM雷达通过在平方律接收机中形成中频梳状频谱，支持延伸至太赫兹扫频范围的极宽有效带宽，为超分辨率测距开辟路径；且SIL显著降低发射机相位噪声，实现高精度距离测量。本文从理论上描述并实验演示了该AFM雷达的SIL工作，所提出的雷达实验实现亚毫米级距离分辨率与<0.002%的距离精度，可对带有微米级特征的覆盖印刷字母成像。
英文摘要
Sub-terahertz (sub-THz) and terahertz (THz) frequency-modulated continuous-wave (FMCW) radars have opened a plethora of scientific and industrial applications, especially in the imaging field. While strong candidates for sub-THz/THz FMCW radar imagers are implemented using photonic methods, there is a desire to achieve the full integration and portability that only electronics can offer. However, integrated electronic sub-THz/THz FMCW radars have significantly lower bandwidth (< 100 GHz) than photonic-based radars, restricting the radar range resolution to the millimeter scale (> 1.5 mm). In addition, the electronic FMCW radar's broad bandwidth comes with increased transmitter phase noise, consequently degrading the radar range accuracy. Here, we present a sub-THz fully-integrated autodyne frequency-modulated (AFM) radar utilizing a self-injection locking (SIL) mechanism that fundamentally overcomes the aforementioned challenges of FMCW radars. The AFM radar supports an exceptionally wide effective bandwidth extending into the terahertz sweep range by forming an intermediate frequency comb spectrum in a quadratic receiver, unlocking the path for super-resolution ranging. Furthermore, SIL significantly reduces the transmitter's phase noise, allowing high-accuracy range measurements. We theoretically describe and experimentally demonstrate the SIL operation of the AFM radar. The proposed radar experimentally achieves sub-millimeter range resolution and a range accuracy of < 0.002%, enabling the imaging of covered printed letters with micrometer features.
