Want to wirelessly upload hundreds of movies to a mobile device in a few seconds? Researchers at Georgia Tech have drawn up blueprints for 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 could be done at a range of about one meter using a graphene antenna, which would make it possible to obtain 10 high-definition movies by waving your phone past another device for one second. Akyildiz and colleagues have also calculated that at even shorter ranges, such as a few centimeters, data rates of up to 100 terabits per second are theoretically possible.
Graphene is a sheet of carbon just one atom thick, in a honeycomb structure, and it has many desirable electronic properties. Electrons move through graphene with virtually no resistance—50 to 500 times faster than they do in silicon.
To make an antenna, the group says, graphene could be shaped 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.
A paper describing the design and related calculations will appear in IEEE’s Journal of Selected Areas in Communication later this year. The paper builds on other research on graphene’s electronic properties, but is the first to calculate optimal configurations of the antennas.
“This points out and provides a set of classical calculations on estimates of sizes and performance: it points out that there is something worthwhile here,” says Phaedon Avouris, an IBM fellow who leads graphene and other nanometer-scale technology at IBM Research in Yorktown Heights, New York. “It doesn’t solve the whole problem, but points out an opportunity.”
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.”
Of course, myriad challenges lie ahead. Antennas don’t work alone; they rely on many 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.
Researchers also need to work out how to do the manufacturing. Working with the material is extremely tricky, because its properties change when it comes in contact with other materials.
However, the Georgia Tech group hopes to make a prototype of an antenna within a year, Akyildiz added, and other components after that.
The calculations are the latest testament to the striking possibilities of graphene, which is seen as providing high-performing transistors, photovoltaics, and other electronic devices (see “Research Hints at Graphene’s Photovoltaic Potential” and “Graphene Transistors”).