Flexible Optically Transparent Antennas

Abstract

Communication in today’s world has never been more connected than it is now, much of which is taking place wirelessly. Every device that communicates wirelessly does so by means of an antenna. Devices nowadays, especially cellular devices, often times have multiple antennas for different protocols. WiFi, GPS, GSM, and Bluetooth are typically well represented and have become standard features. We have seen the evolution of these antennas and the trend is clear: smaller, lighter, and more efficient. Today’s cellular devices include novel antennas that do not protrude from the device, which allow the device maker to focus more on the aesthetics. As the room for the antenna in these devices becomes more cramped, newer and more innovative solutions must be devised to keep up with demand. Antennas that can conform to different shapes clearly have an edge over their rigid counterparts, and many companies now are already developing devices that are completely flexible. Wearable antennas that can provide connectivity between multiple devices in close proximity and then to the outside world are not out of the question. In the world of displays, this flexible technology is already in place. In fact, the Flexible Display Center at Arizona State University is providing many services related to the development of flexible and transparent thin film technologies. There are opportunities for component makers to dive into this market and that includes antenna designers. For the antenna designer, this presents unique challenges due to the fact that the antenna will need to be flexible while maintaining radiation characteristics, as well as robust enough to survive mechanical distortions. In this chapter, state–of-the-art designs and fabrication techniques of optically transparent antennas are surveyed. Moreover, a case study of a flexible transparent monopole antenna based on indium tin oxide and kapton polyimide substrate is presented. www.witpress.com, ISSN 1755-8336 (on-line) WIT Transactions on State of the Art in Science and Engineering, Vol 82, © 2014 WIT Press doi:10.2495/978-1-84564-986-9/003 60 InnovatIon In Wearable and FlexIble antennas