Theoretical and Experimental Studies of THz Wireless Communication Signal Transmitting Through Window Glass

6G wireless communication is expected to offer data rates that are 100 to 1000 times faster than 5G, enabling seamless transfer of massive amounts of data with ultra-low latency. This will significantly enhance the user experience in various applications, such as virtual reality, augmented reality, and realtime gaming. 6G networks will utilize higher frequency bands like the Terahertz (THz) range, which has abundant spectrum resources and the potential to achieve extremely high data rates. This work derives a theoretical model for analyzing the interaction of THz waves from 0.2 to 2THz with window glass plates. With assumption of THz wireless communication signal being perfect plane electromagnetic wave and of windows glass having two parallel surfaces, the millimeter wave signal will reflect and transmit at the interface between glass and air. The transmitted wave reflects and transmits at other interface. All the reflected and transmitted waves will have multi-reflection, multitransmission and multi-interference, thus form resonant cavity modes in the glass plate. This model may be used to calculate the reflectance and transmittance of THz waves transmitting through the glass plates. The calculated results show that the transmittance is very closely linked to the frequency of the wave and the thickness and refractive index of the glass plates. An experiment is conducted to measure the transmission spectra ranging from 0.22THz to 0.32THz. The measured transmittances are in agreement with calculated ones, indicating that the model proposed in this work may be used to analyze the transmissions and reflections of THz waves through window glass plates.