“T-ray” technique means ultra-fast wireless

Wireless connections over an ultra high frequency range could mean data transfers at up to 20 times current speeds.

Newly published research into the “T-ray” band shows there could be huge potential for the frequencies, which is particularly intriguing as they are currently unregulated by broadcasting authorities.

The T in the name stands for terahertz, though the band is generally considered to cover everything from 300 GHz to 3THz. In practice, it’s the frequency range between microwave and infra-red.

Scientists at the Tokyo Institute of Technology report achieving speeds of 3Gbps over the 542GHz frequency, double the figures achieved in a previous public demo. (To put that into context, it’s the equivalent of transferring the entire contents of a Blu-ray disc in just over a minute.) They say that while practical issues will be a limit, on paper a speed of 100Gbps would be possible.

To date the T-ray frequencies have mainly been used for imaging that works in a similar way to X-rays, but causes less physical damage. Using the frequencies for data transmission has previously proved unviable not just because of cost, but because the equipment would be too bulky and require too much power for practical use, particularly in mobile devices.

The key to the Tokyo project is the use of a resonant tunnelling diode (pictured: credit IET). The BBC explains that such diodes are unusual because “the voltage they produce can sometimes go down as current is increased.” The result is that the electrons that carry information can be passed through extremely quickly in a tiny diode, as small as one square millimeter.

As T-rays only have a range of about 10 meters, they certainly aren’t going to be a substitute for mobile broadband. If they ever are adapted for consumer use, the chances are they’d only ever find a market if and when existing wi-fi technology proves inadequate.