不同粗糙度抛物面的2.52 THz后向散射测量

Measurement of 2.52 THz back scattering in different roughness paraboloid

太赫兹后向散射特性是表征目标对太赫兹波散射能力的一个重要参数。在实际应用中抛物面形状占据了重要位置,而在2.52 THz频率下的相关散射特性的研究至今处于空白。利用已搭建的测量系统对直径为50、60、70、80 mm,粗糙度为3.2、6.3、12.5μm等的抛物面进行了太赫兹后向散射的测量。利用MATLAB软件对数据进行处理并得出目标的太赫兹后向散射特性曲线。利用控制变量法分别研究尺寸和粗糙度对目标太赫兹后向散射的影响。随着尺寸的增大,目标的散射特性曲线下降变缓,在3°附近出现的凸起越来越明显。用示波器在所测角度边缘观察信号波形表明信号处于可测状态。后向散射测量实验结果表明,测量动态范围最大可达22 d B,最大误差约为0.15 d B。

Terahertz back scattering properties is a very important index to represent the target ′s scattering ability of terahertz. Paraboloid occupies an important position in practical applications, but the correlational studies on 2.52 THz target back scattering properties still remain untouched so far. The back scattering measurement experiments on paraboloid with diameter of 50, 60, 70 and 80 mm based on measurement system were conducted. The roughness of paraboloid was 3.2, 6.3, 12.5 μm and so on. The MATLAB software was used to deal with the data and the target back scattering properties curve was got. The controlling variable method was used to study size and roughness effects of target terahertz back scattering properties. Target back scattering properties curve dropped slowly as it grew in size, and the lug boss nearby 3° was becoming more and more obvious. The signal waveform of measuring angle edge was observed by the oscillograph which proved the signal was available. Back scattering experiment results show that the maximum measurement dynamic range is 22 d B and the maximum measurement error is about 0.15 d B.