高斯光圆柱太赫兹雷达散射截面的影响

Influence of Gaussian Beam on Conductor Cylinder Terahertz Radar Cross Section

通过对缩比模型的太赫兹波段雷达散射截面（RCS）测量，可以获得微波波段全尺寸目标的RCS值，因此，RCS估算和测量是当前太赫兹重要的应用技术之一。RCS估算中，通常假定入射光为均匀平面波，但在实际测量应用中，常常采用发射类似高斯光束的太赫兹源。进行了横电波情况高斯光束入射时，无限长理想导体圆柱的太赫兹雷达散射截面估算。仿真研究了2．52THz激光准直入射和相位变化对后向雷达散射截面的影响，给出了RCS与散射角的变化曲线；同时与均匀平面波入射结果进行了比较分析。仿真结果表明，在测量圆柱半径10mm且入射光距圆柱轴心距离1ITI处的后向RCS时，用光斑半径30mm的高斯光束较好。

By measuring radar cross section （RCS） of scale model, the RCS of the full size target at microwave band is acquired. The estimation and measurement of the terahertz radar cross section is one of the most important applications in terahertz technique. In the RCS estimation, usually a plane wave is assumed; while in real measurement, generally a Gaussian beam or a similar beam resource is adopted. The RCS of an infinite perfect conductor cylinder is estimated under the condition that the incident wave is transverse electric wave. In the estimation, the influence of 2.52 THz collimated laser beam and phase variation on backward RCS are studied and the RCS with scattering angle is obtained~ at the same time, a comparison between plane wave and Gaussian beam is also given. The estimation results show choosing facula radius 30 mm is appropriate when cylinder radius is 10 mm and the distance between the cylinder and the beam source is 1 m.