Wang Anle, Zheng Daikun, Du Shirui, Zhang Jin, Du Pengfei, Zhu Yong, Cong Wenshan, Luo Xiong, Wang Yalan, Dai Yitang
Opt Express. 2021 Apr 26;29(9):13887-13898. doi: 10.1364/OE.423952.
Both effective detection demand against diversified development of flight targets and remote sensing providing identifiable and fine target information all call for microwave radar system with flexible and ultra-wideband frequency-domain ability to provide more high-resolution and multi-source information. A microwave photonic radar system with theoretically full-band and ultra-wideband working ability is presented and experimentally demonstrated. An optical frequency operation module is employed in the transmitter to break the frequency-domain limitation on the emitted radar signal, while two types of optical mixing structures are switched to provide the ability to receive target echoes at any frequency band. In the experiments, high-SNR optical frequency operation and subsequent waveform generation at each normal radar band, that is from HF to Ka, are carried out. Good linearity and coherence of the generated waveforms are also demonstrated. Then, multi-band system-level detection experiments are completed to show the full-band working ability. Centimeter-scale or even sub-centimeter-scale resolution are realized at different bands, which identifies the proposed system can handle target detection with flexible performance and support acquiring rich target information at different frequency bands in future.
对飞行目标多样化发展的有效探测需求以及遥感提供可识别的精细目标信息，都需要具备灵活且超宽带频域能力的微波雷达系统，以提供更多高分辨率和多源信息。本文提出并通过实验演示了一种理论上具有全频段和超宽带工作能力的微波光子雷达系统。发射端采用光频运算模块来突破发射雷达信号的频域限制，同时切换两种光混频结构以提供在任何频段接收目标回波的能力。在实验中，在从高频（HF）到Ka波段的每个常规雷达频段进行了高信噪比光频运算及后续波形生成。还展示了所生成波形良好的线性度和相干性。然后，完成了多频段系统级探测实验以展示全频段工作能力。在不同频段实现了厘米级甚至亚厘米级分辨率，这表明所提出的系统能够灵活地处理目标探测，并支持未来在不同频段获取丰富的目标信息。
