The fifth-generation technology for mobile networks – 5G – was introduced in 2016. Both 4G and 5G operate on frequencies up to the gigahertz (GHz) range. Higher frequencies support faster data transfer.

High-band frequencies for 5G are usually between 50 and 70 GHz.

The next frontier of telecommunications is entering the terahertz (THz) range. These frequencies would see wireless speeds far exceeding current systems.

The new chip, designed by a team led by Australian researchers, has been successfully tested at the sub-terahertz J-band of 220–330 GHz. This shows the device could be used for 6G communications and beyond.

It is detailed in a paper published in the Laser & Photonic Reviews.

Operation schematic of the proposed all-silicon terahertz integrated polarization (de)multiplexer. Credit: Dr Weijie Gao / Osaka University.

The chip is the world’s first ultra-wideband integrated terahertz polarisation (de)multiplexer on an all-silicon base. A multiplexer is a device that can select between different signals and forward a specific signal to an output line.

In this case, the chip can divide waves by the direction of their oscillations – called polarisation.

“Our proposed polarisation multiplexer will allow multiple data streams to be transmitted simultaneously over the same frequency band, effectively doubling the data capacity,” says senior author Withawat Withayachumnankul, a professor at the University of Adelaide.

“This large relative bandwidth is a record for any integrated multiplexers found in any frequency range.

“As a result, the polarisation multiplexer is a key enabler in realising the full potential of terahertz communications, driving forward advancements in various fields such as high-definition video streaming, augmented reality, and next-generation mobile networks such as 6G,” says first author Wijie Gao who worked on the project while at the University of Adelaide and is now a researcher at Japan’s Osaka University.

The researchers say the new chip could see implementation of 6G technology over the next decade. It uses the same fabrication methods as standard silicon devices, allowing cost-effective large-scale production.

“We anticipate that within the next 1 to 2 years, researchers will begin to explore new applications and refine the technology,” says co-author Masayuki Fujita, a professor at Osaka University.

“Within a decade, we foresee widespread adoption and integration of these terahertz technologies across various industries, revolutionising fields such as telecommunications, imaging, radar, and the internet of things,” Withayachumnankul adds.

This article first appeared in Cosmos Science.