线性调频连续波(LFMCW)信号应用于机载虚拟阵多输入多输出(MIMO)雷达体制。二者的结合,一方面,可在较少阵元条件下,获得虚拟的宽口径,改善雷达的测角性能;另一方面,采用连续波体制,在相同峰值发射功率的条件下,可增大雷达的探测距离,弥补MIMO 雷达宽波束发射导致的威力下降。LFMCW 信号的匹配滤波输出拖尾较长,文中对由此产生的杂波距离旁瓣泄漏问题进行了建模与分析,结果表明:LFMCW 雷达系统与线性调频脉冲雷达系统具有相似的杂波距离旁瓣泄漏特性,数值仿真验证了此结果的正确性。另外,非自适应处理的仿真结果也表明对高速、小RCS 的目标,LFM鄄CW 信号具有更高的输出信杂噪比。

Linear frequency modulated continuous wave ( LFMCW) signal is introduced in airborne multiple-input multiple-output (MIMO) radar system. The combined system, on one hand, a large virtual aperture is acquired that improves the performance of angle measurement, when a relatively small amount of antennas are available. On the other hand, when equivalent peak power is transmitted, adopting LFMCW signal can lengthen radar detection range and compensate the power loss due to wide-area transmitting for MIMO radar. The LFMCW signal has relatively long duration, from which the clutter leakage issue arises and it may degrade the performance of target detection. Through modeling and analysis, the clutter leakage issue is addressed and it is found that the proposed system has the same clutter leakage property with the linear frequency modulated pulse ( LFMP) radar system. Numerical simulations verified the result. Moreover, it is demonstrated that the proposed system has higher output signal to clutter plus noise ratio than the LFMP system, especially for target with high speed and small radar cross section (RCS).

TN958

国家自然科学基金资助项目(NSFC61401062)