Study on Terahertz RCS Scaled Measurements for Metal Plates of Rough Surfaces

The technique of scaled measurements for radar cross sections (RCSs) is one of the important means to study the scattering characteristics of targets. Based on the electrodynamic similitude, the scaling relation works well for RCS scaled measurements in microwaves. However, in the terahertz (THz) region, due to the shortened wavelength, the contribution of the fine structure of the targets, such as surface roughness, cannot be ignored. This leads to the inconsistency of the electrodynamic similitude in the THz band. In this paper, segmented RCS scaling relation was proposed for THz RCS scaled measurements, which considered the randomness of surface roughness. The validity of the new scaling relation has been proved by both numerical simulation and measurement experiments. This work provides references for practicing RCS scaled measurements of targets with consideration of surface roughness in the THz spectrum.