多子带频域超宽带合成雷达半实物仿真

Hardware-in-the-Loop Simulation of Multi-subbands Frequency Domain UWB Synthetic Radar

宽带合成技术是实现距离向高分辨的一种有效手段,目前频域宽带合成方法拓展至超宽带合成,合成带宽受限,合成信号质量随子带数增加而恶化。针对这些问题,提出了一种适用于频率步进线性调频信号的多子带频域超宽带合成方法,采用预失真、子带间高精延时对齐、相位自适应调整等技术对影响信号合成质量的系统失真、延时误差、子带拼接处相位跳变改进,并搭建步进频雷达半实物仿真系统以验证所提方法的有效性及合成信号性能。实验结果表明,43个28 MHz带宽的子脉冲合成的超分辨距离向信号,带宽为1.0357 GHz,时间分辨率高达0.8720 ns,具有良好的点目标分辨性能,未来可应用于二维合成孔径雷达超分辨成像。

Wideband synthesis technology is an effective method to achieve high range resolution.At present,if the frequency domain wideband synthesis method is applied to ultrawideband(UWB)signal synthesis,synthetic bandwidth will be limited and the synthesized signal quality will deteriorate with the increase of the number of subbands.For above problems,multi-subbands UWB synthesis method for stepped frequency linear frequency modulation signals is proposed.The technologies of the predistortion,high-precision delay alignment between subbands and phase adaptive adjustment are used to improve system distortion,delay error,phase jump at subband splicing that affects the quality of signal synthesis.To verify the effectiveness of the method and the performance of the synthesized signal,a stepped frequency hardware-in-the-loop simulation system is built.The experimental results show that the UWB signal synthesized by 4328 MHz subbands has a bandwidth of 1.0357 GHz and a time resolution of 0.8720 ns.It has excellent point target resolution performance and can be applied to two-dimensional synthetic aperture radar super-resolution imaging in the future.