Influence of Gaussian Beam on Terahertz Radar Cross Section of a Conducting Sphere

In RCS estimation, usually a plane wave is assumed; while in real measurements at terahertz frequencies, generally a Gaussian beam or a similar beam source is adopted. In this paper, the RCS of a conducting sphere is discussed under the condition that the incident wave is a Gaussian beam. In the estimation, the influence of 2.52 THz collimated laser beam on RCS is discussed and the RCS changing with scattering angle and some other factors is obtained; at the same time, the comparisons between different incident beams, plane wave and Gaussian beam, are also given. The estimation results show that choosing a beam width of 40 mm is appropriate when the sphere radius is 10 mm and the distance between the sphere and the beam source is 1 m.