Complex Permittivity Evaluation of Building Materials at 200-500 GHz Using THz-TDS

In 6G mobile communication, 300-GHz-band terahertz (THz) system is a promising candidate for achieving ultra-high-speed wireless communication. However, the experimental data on the reflectance and transmittance of building materials at 300GHz were insufficient. In this paper, we employed terahertz time-domain spectroscopy (THz-TDS) spectroscopy to obtain the complex permittivity of building materials, glass, concrete, and granite at 200-500 GHz in order to calculate the reflectance and transmittance of building materials. In THz-TDS spectroscopy, the effect of multiple reflections was removed by time-gating the acquired waveform. We conducted 300-GHz-band indoor propagation simulation by using the calculated complex permittivity of building materials.