Guowen Ding , *Ping He, Labforinvention Corporation, Fremont, CA
Energy-efficient, low-emissivity (low-E) windows not only block infrared light radiation but also cellular signals. Signal attenuation due to low-E windows is severe (30+ dB), a problem that will get worse with the continued deployment of 5G networks. Existing solutions to overcome signal blocking consist of installing routers and antennas, which requires additional upfront investment and incur ongoing maintenance and upgrade costs. Alternatively, low-E windows can be laser scribed to enable limited signal penetration at the tradeoff of visual clarity, durability and with added costs. The optimal solution would be for low-E windows to block infrared heat while enabling cellular signals to pass through, all while maintaining low-E’s optical and thermal performance at a cost competitive manufacturing level. In this presentation, we provide an overview of the market, current solutions and present our patent-pending innovation on cellular signal transmissive low-E window coating technology. Our prototype has demonstrated excellent 5G (low-band) frequency transmission and excellent visual clarity, while maintaining annealed and tempered low-E performance, including optical (transmission, reflection, color), thermal (emissivity, SHGC, U-value), and multiple durability tests.