A study on the efficiency of transparent patch antennas designed from conductive oxide films

A study on the efficiency of transparent patch antennas designed from indium tin oxide (ITO) films is presented to provide design guidelines for patch type transparent antennas. The trade-offs between optical transparency and antenna efficiency is analyzed by considering typical material properties of ITO films. It is shown that the efficiency of a patch antenna designed from ITO films is determined by the electron mobility of ITO films, operational frequency, and the substrate material. The study shows that with today´s material processing methods, it is feasible to achieve at least 30% efficiency of an ITO antenna with 90% optical transparency for operational frequency higher than 5 GHz. While progress in material science may improve the antenna performance, the highly transparent patch antenna with 30% efficiency may be employed in array design for practical implementations.