基于改进波形太赫兹雷达的多目标检测

Multi-target detection of terahertz radar based on improved waveform

太赫兹雷达在测点目标时具有极高的分辨力。然而在多目标条件下,使用经典的线性调频波形调制可能会引起错误的差频组合,从而出现虚假目标。为此,提出一种工作在0.22 THz频段的改进波形,它由梯形波与三角波两部分组成。通过梯形波的上、下扫频计算速度-距离的模糊范围,并通过恒频段检测目标的相对速度。由于速度-距离交叉点的不匹配,虚假目标仍存在,而后续的不同调频斜率的三角波则能在其基础上完全剔除虚假目标。文中给出了这种体制的太赫兹雷达系统的架构,并通过近乎现实的仿真,证明在这种新型波形体制下,太赫兹雷达差频配对的准确度将得到大幅度提升。

Terahertz radar has extremely high resolution when measuring single targets.However,under multi-target conditions,the use of classical chirp waveform modulation may result in false difference frequency combinations,thus creating ghost targets.Aiming at this problem,a design scheme of multi-target detection for terahertz radar with improved waveform working at 0.22 THz is proposed.It consists of two parts:trapezoidal wave and triangular wave.The speed-distance blur range is calculated by the upper and lower sweep of the trapezoidal wave,and the relative speed of the target is detected by the constant frequency band.Nevertheless,the ghost target still exists owing to the mismatch of the velocity-distance intersection.The subsequent triangular waves with different frequency modulation slopes can help completely eliminate the ghost target.The architecture of the terahertz radar system is given in this paper,and through the near-realistic simulation,it is proved that the accuracy of terahertz radar for difference frequency pairing will be greatly improved under this new waveform system.