A comparative study on two types of transparent patch antennas

Properties of optically transparent patch antennas designed from meshed conductor and transparent conductive films are studied and compared. It is shown that at S band, meshed antenna provides the best antenna efficiency for the highest transparency. It is practical to design a 90% transparent meshed antenna with more than 60% transparency. Indium tin oxide (ITO) films, although less visible to human eyes than conductive meshes, at an optical transparency of 80%, provide an antenna efficiency of less than 30% at 2.5 GHz. AgHT (silver coated polyester film) film has lower transparency compared to ITO films for the same antenna efficiency. It is also shown that with the progress in material processing, the efficiency of an ITO patch antenna can be improved to be comparable to a meshed one. In addition, one can improve the efficiency of an antenna designed from ITO films by increasing the operational frequency.