提出一种基于互逆光纤色散的微波光子雷达系统设计方案, 既可以产生宽带线性调频信号, 又可以实现线性调频信号的光域脉冲压缩.在发射端利用互逆色散光纤产生线性调频信号.在接收端, 雷达回波信号通过马赫-曾德调制器调制到预啁啾的光信号上, 然后经过色散光纤的进一步色散.最终在探测器端可以得到目标回波信号脉冲压缩后的结果.该方案无需脉冲压缩过程中数字化和离线处理, 且具有脉冲压缩比的调谐作用.理论、数值仿真和实验证明了该设计方案能有效进行线性调频信号的光域脉冲压缩.实验产生了C波段下时宽1.2 ns, 带宽3.2 GHz的线性调频信号, 并通过互逆色散光纤将该信号压缩到了0.09 ns, 脉冲压缩比达13.3.

A scheme of microwave photonic radar architecture based on mutual optical fiber dispersion was proposed, including generation and compression of wideband linear frequency modulation signal. Linear frequency modulation was generated at the transmitting end by using the mutual dispersion fiber. At the receiving end, the radar echo was modulated by the Mach-Zehnder modulator onto the pre-chirped optical signal, and that was further dispersed in the optical dispersion fiber. Finally, the pulse compression signal of the target echo can be obtained at the detector end. The linear frequency modulation signal can be directly compressed by the proposed technique in the optical domain without digital signal processing during pulse compression process, and the pulse compression ratio could be further programmable. The numerical simulations and experimental results showed that the proposed scheme can effectively perform the pulse compression of the LFM in the optical domain. A linear frequency modulation signal with temporal width of 1.2 ns, bandwidth of 3.2 GHz in the C-band was generated by the experiment, and that was compressed to 0.09 ns through the mutual dispersion fiber. The pulse compression ratio is up to 13.3.