RF/MW Transmission Improvement in Energy Efficient Buildings Using FSS and Its Impact on Thermal Efficiency of Energy-Saving Glass

A layer of metallic oxide is usually employed on one side of energy-saving glass (ESG) to pass the visible frequencies and to restrict the infrared (IR) waves. The technique increases the thermal efficiency of ESG; however, it attenuates the radio frequency (RF), and microwave (MW) signals due to the resistance of metallic oxide, thus mobile communication is significantly degraded. In this paper, transmission of RF and MW and IR frequencies through ESG has been investigated by etching band-pass frequency-selective surfaces (FSSs) in the ESG coating. However, the thermal efficiency of ESG decreases due to the etching of FSS. Thermal simulations have been conducted to investigate the heat efficiency of the FSS design. A band-pass FSS has been designed in the 0.1–3.5 GHz band which provides transmission improvement of up to 26 dB. Wireless Local Area Network (WLAN) security and confinement is also ensured for 4–6 GHz by restricting signals inside the building. The amount of area etched is minimized in order to avoid heat loss. The TE and TM polarization for normal and oblique angle of incidence up to 60° was achieved and verified through experimental results. Moreover, the thermal efficiency of ESG and the impact of band-pass FSS on ESG has also been investigated. WLAN security, RF/MW transmission improvement, transmission bandwidth, and thermal efficiency have all been significantly improved in comparison with state-of-the-art designs. Theoretical transmission results were obtained using ANSYS HFSS, and transmission of RF/MW signals has been verified through the measured results. Theoretical results for the thermal analysis of ESG have been obtained using COMSOL Multiphysics software.