太赫兹稀疏阵列相干因子栅旁瓣抑制方法

在太赫兹成像中,阵列的稀疏化设计会引起栅旁瓣的恶化。在传统相干因子(Coherence Factor,CF)加权的基础上设计了适用于多输入多输出(Multiple-Input Multiple-Output,MIMO)稀疏成像阵列的相位相干因子(Phase Coherence Factor,PCF)和符号相干因子(Sign Coherence Factor,SCF)两种加权栅旁瓣抑制方法。对点目标仿真结果表明,CF、PCF和SCF栅旁瓣抑制后峰值旁瓣比(Peak Side Lobe Ratio,PSLR)分别降低了17.81 dB、24.56 dB和22.74 dB,在340GHz 4T16R稀疏阵列成像系统中的实测结果也表明,PCF和SCF对栅旁瓣的抑制效果分别优于CF6dB和4dB以上。

Grating-lobes suppression methods based on coherence factor for terahertz sparse array

In terahertz imaging, the sparse design of the array can cause degradation of the grating-lobes. In this paper, based on the traditional coherence factor(CF) weighting method, phase coherence factor(PCF) and sign coherence factor(SCF) are designed, which are applied to multi-input and multi-output(MIMO) terahertz sparse array imaging grating-lobes suppression. The simulation results of the point target show that the peak side lobe ratio(PSLR) is reduced by 17.81 dB, 24.56 dB and 22.74 dB after grating lobes suppressed by CF, PCF and SCF, respectively. The results measured in the 340 GHz 4T16R sparse array imaging system also show that the suppression effect of PCF and SCF on grating lobes is 6dB and 4dB better than CF, respectively.