The Terahertz band sits between the microwave and infrared regions of the spectrum and ranges from 300GHz to just under 3THz. The band is unregulated by telecoms agencies and is used primarily for imaging in research environments, because so-called “T-rays” cause less damage than X-rays when penetrating materials.
Using a wireless radio no bigger than a penny, the researchers were able to achieve a data transfer rate of 3Gbps at a frequency of 542GHz, smashing the previous record set by electronic component firm ROHM, which demonstrated a 1.5Gbps transfer rate at 300GHz in 2011.
The wireless radio uses a tiny device known as a resonant tunnelling diode (RTD) that can reduce voltage as current increases. By tuning the current correctly, the researchers were able to make the diode oscillate and spray out signals in the Terahertz band.
According to the report, published in Electronics Letters, Terahertz Wi-Fi could theoretically support data rates up to 100Gbps – around 15 times higher than 802.11ac, which is the newest Wi-Fi standard available to consumers.
The researchers admitted that Terahertz Wi-Fi only works over ranges of about 10 meters, (higher frequency signals have greater capacity but cannot travel as far as lower frequencies), and also requires line of sight between communicating devices. However, it could feasibly be used to enable servers to share data wirelessly within server farms.
Range could also be improved by using high-power oscillators and attaching high-gain antennas, according to the researchers. The team is now working to improve their proof-of-principle device and extend its range deeper into the Terahertz band.
