What are Transparent Antennas?

A Transparent antenna is an antenna that is optically transparent or allows the passage of visible light up to a certain degree through the antenna. Such an optically transparent antenna can be integrated on the surface of windows, screens, and car sunroofs without any significant visual impact on the surface. This type of antenna can also be applied across a larger surface thereby providing better performance.

Materials of a Transparent Antenna

At present, there are four kinds of materials that can be used to make optically transparent antennas:

1. A transparent metal oxide film, for example, indium tin oxide film (ITO film). A compromise must be made between the light transmittance and surface impedance when using ITO films for designing the antenna. 

2. An AgHT series multilayer thin film. Compared to the ITO film, the AgHT film has better conductivity and worse transmittance. 

3. An ultrathin metal film made of copper, silver, gold, and other metal conductors. Antennas made of this material have high radiation efficiency. But the light transmittance is pretty low. 

4. A Metal mesh antenna, which has higher radiation efficiency, and whose light transmittance is higher than that of the ultrathin metal film. But the requirements for the processing technology of this material are very high. Considering the light transmittance, conductivity, and processing technology of the four materials, ITO film is the best choice currently to make transparent antennas. ITO film is also the most widely used material in the research and design of optically transparent antennas.

After over a decade of development, the study of materials that can be used to make transparent antennas has been very comprehensive and extensive. The basic principles of optically transparent antennas have been mastered. Nowadays, the applications of optically transparent antennas in actual scenarios are attracting more attention. An optically transparent GPS antenna can be integrated into a car’s windshield. A transparent RFID reader antenna can be fitted for smart fitting room applications. Optically transparent antennas can be placed over solar panels of satellites which would conserve space utilized to integrate antennas in the main body of satellites.

Transparent antennas can also be used in radar absorbing & scattering, beam steering (including radar detection) and as Bluetooth antennas in wearable devices like smartwatches, fitness bands etc. Transparent antennas will find applications in almost any device with a display that also supports connectivity of some kind (Wi-Fi, Bluetooth, cellular etc.). In such devices, antennas can be then integrated over the displays rather than inside the device body which will reduce the overall size of the device and make them more compact or slimmer.

Click here to view transparent antennas from the leading manufacturers.