WiFi band-stop FSS for increased privacy protection in smart building

This paper proposes a periodic double ring strip frequency selective surface (FSS) with dual-band stop behavior. The FSS elements are designed to be etched on the transparent coating of glass substrate in smart buildings, which acts as a dual-band notch filter on 2.45GHz and 5.4GHz to avoid the leakage of WiFi signal outside the building. All the simulation parts are simulated by using High Frequency Structure Simulator (HFSS). The proposed FSS possesses 450MHz and 960MHz bandwidth with insertion loss more than -10dB around the two central operating frequencies 2.45GHz and 5.45GHz, respectively. Furthermore, the unit-cell structure provides a stable performance for both TE and TM polarizations with incident angles 0°-60°. A prototype of the proposed FSS is fabricated and measured. Good agreement between the simulated and measured results is obtained.