Transmission analysis of energy saving glass windows for the purpose of providing FSS solutions at microwave frequencies

An inherent transmission problem associated with modern energy-saving glass windows is analyzed. These windows are used in building design to provide thermal insulation which keeps the interior warmer in the winter and cooler in the summer. This thermal insulation is achieved by employing a very thin layer of metallic oxide on one side of the ordinary (float) glass. This layer attenuates infrared waves while remaining transparent to ultraviolet frequencies. But this metallic oxide coating also attenuates the transmission of useful RF/microwave signals (GSM, GPS etc) through the glass window. We have investigated the transmission of microwave frequencies through OptithermtradeSN glass window manufactured by Pilkington. At average, about 30 dB attenuation is observed from 800 MHz to 6 GHz for both TE and TM polarizations at normal incidence. Theoretical and measured results are presented.