Screen printed frequency selective surfaces for room isolation in buildings

A ring type frequency selective surface (FSS) can provide transmission stop-band characteristics in rooms. This allows adjacent rooms to be isolated for one LAN for frequency reuse while other frequencies pass through the walls with minimal attenuation. The FSS was screen printed on a thin flexible plastic substrate of permittivity 3.2 with a stop band at 12.3GHz and 10dB bandwidth of 3.5GHz. The variation in bandstop characteristics was investigated for various wall materials. The centre frequency varied by more than 3 GHz for common wall materials which means significant transparency for some building materials. The technique is a low cost method of confining LAN picocells in one room.