Propagation Characteristics and Modeling of Monostatic RCS Scattering From Indoor Building Material Above 215-GHz Frequency Bands

This letter presents an investigation into the response mechanisms and characteristics of indoor building materials to sub-terahertz (THz) waves. Additionally, a monostatic radar cross-section (RCS) scattering model is proposed to facilitate indoor sensing communication. Initially, measurement campaigns are conducted to analyze the monostatic RCS of six indoor building materials at the 215-225 GHz and 280-290 GHz frequency bands, considering both horizontal and vertical polarizations. The results indicate a decrease in the RCS of all materials as the incidence angle increases. Moreover, materials with higher complex dielectric constants exhibit the largest RCS at an incident angle of 0 degrees. Subsequently, a novel monostatic RCS scattering model is proposed by modifying the Kirchhoff approximation model. The proposed model accounts for incident angles, frequency, surface roughness, and wave polarization. The investigation of indoor building materials' response mechanisms and characteristics to sub-THz waves, along with the proposed monostatic RCS scattering model, provides valuable guidance for modeling sub-THz sensing channels.