Graphene Antennas to Reach Terabits of Wireless Bandwidth

A big bottleneck of current data transfer technology, the slow speed of wireless transfers, is now in the early stage of being addressed. Researchers at Georgia Tech presented the concept of a wireless antenna made from atom-thin sheets of carbon, or graphene, that could allow terabit-per-second transfer speeds at short ranges.

“It’s a gigantic volume of bandwidth. Nowadays, if you try to copy everything from one computer to another wirelessly, it takes hours. If you have this, you can do everything in one second—boom,” says Ian Akyildiz, director of the broadband wireless networking laboratory at Georgia Tech.

A terabit per second, or about 3000 times the speed of a fast WLAN, could be achieved at a range of about one meter using a graphene antenna. Akyildiz and colleagues expect that data rates as high as 100 terabits per second are theoretically possible at shorter ranges of a few centimeters.

Graphene is a very promising nano-scale material consisting of a sheet of carbon just one atom thick, featuring a honeycomb structure, because it has many desirable electronic properties. Electrons can move through graphene with virtually no resistance—50 to 500 times faster than they do in silicon.

The group proposes to make an antenna by shaping graphene into narrow strips of between 10 and 100 nanometers wide and one micrometer long, allowing it to transmit and receive at the terahertz frequency, which roughly corresponds to those size scales. Electromagnetic waves in the terahertz frequency would then interact with plasmonic waves—oscillations of electrons at the surface of the graphene strip—to send and receive information.

As well as facilitating high-speed communication between devices, graphene antennas could enable faster wireless connections between nanoscale components on chips. “Antennas made of graphene can be made much smaller in all dimensions than a metal wire antenna. It can be made to be on the order of a micrometer or a few nanometers,” Avouris says. “The significance is that the antenna can be incorporated in a very small object.”

A research paper describing the design and related calculations is set to appear in IEEE’s Journal of Selected Areas in Communication later in 2013. The paper will be the first to calculate optimal configurations of the antennas, but builds on other research on graphene’s electronic properties.

Also, the Georgia Tech group hopes to make a prototype of an antenna within a year, Akyildiz added, and other components after that, even though difficult challenges need to be tackled for that. Antennas don’t work alone but rely on several other components—such as signal generators and detectors, amplifiers, and filters—all of which would have to be fabricated at similar scales and with similar speeds in order to make a complete device.