Resonant tunneling diodes (RTDs) support room-temperature terahertz (THz) oscillation and simultaneous THz-band detection, enabling compact monostatic THz sensors for practical and cost-effective sensing applications. In this paper, we present a highly integrated 280 GHz-band radar system based on a single RTD that exploits the self-mixing effect to generate a low-frequency interferometric signal. The resulting self-mixing signal is further analyzed from a radar perspective and processed to extract micrometer-scale displacement and thin-film thickness variations. Experimentally, the proposed system demonstrates a minimum detectable displacement of approximately 5 um and quantitatively resolves polymer film thicknesses of 12.5, 25, and 50 um.

翻译：共振隧穿二极管（RTD）可在室温下实现太赫兹（THz）振荡与同步THz波段检测，从而构建紧凑型单站THz传感器，用于实用且低成本的传感应用。本文提出一种基于单个RTD的高度集成式280 GHz波段雷达系统，该系统利用自混频效应产生低频干涉信号。进一步从雷达角度分析所得自混频信号，并通过信号处理提取微米级位移与薄膜厚度变化。实验结果表明，该系统的位移最小可检测量约为5微米，并能定量分辨厚度分别为12.5微米、25微米和50微米的聚合物薄膜。