Optically Transparent Antenna Arrays for the Next Generation of Mobile Networks

In this article, we report the first ever antenna array with >90% transparency that is intended for 5G networks for smart cities. This level of transparency is achieved by using Gallium-doped Zinc Oxides. The array designed and tested is for sub-6GHz 5G and operates at 5.8GHz. This seamless design allows such arrays to be integrated into windows of buildings within the smart city to provide consistent network coverage. The phased array has good gain and scanning characteristics as presented below. We have also included a discussion regarding gain and beam steering capabilities in comparison to similar arrays made of conventional copper and RF substrates. This study presents the comparison of two antenna arrays, one constructed from copper antenna elements (Simulated operational band from 5.67 GHz to 6.62 GHz, 7.6% bandwidth, and gain of 2.18 dBi) and one constructed from GZO antenna elements (Simulated operational band from 2.8 GHz to 10 GHz, 112.5% bandwidth, approximately 8% efficiency, and a gain of −10.87 dBi). Both element designs have a 1.5cm by 1.5cm footprint. The results show that a 4x1 array of GZO elements will increase the gain to 0.34 dBi from a gain of −10.87 dBi of a thin film, GZO antenna element. In addition, over 90% transparency allows window integration without obstructing the view. The techniques described in this article also can be used to integrate such arrays in glasses and other transparent materials for various IoT applications.