Microwave and Millimeter-Wave MIMO Antenna Using Conductive ITO Film

This paper will present a novel design of optically transparent multiple-input multiple-output (MIMO) antenna made by indium tin oxide (ITO) films. The MIMO antenna involves patch and monopole antenna elements at 4.9 GHz and 26 GHz respectively. The upper and lower surface of the MIMO antenna are covered by a thin film of glass substrate with conductive ITO coatings, while top layer is radiating elements and the bottom layers is ground planes. Both patch and monopole antennas are fed by transparent 50Ω transmission lines. The prototypes were fabricated by an in-house photolithography process. Measurements are carried out to confirm the simulation. The characteristics showed that the proposed MIMO antenna can be considered as a potential antenna for 5G smartphone communications applications.