Silicon chip propels 6G communications forward

A team of scientists has harnessed the potential of 6G communications with a new polarization multiplexer. Terahertz communications represent the next frontier in wireless technology, promising data transmission rates far beyond those of current systems.

By operating at terahertz frequencies, these systems can support unprecedented bandwidth, enabling ultra-fast wireless communication and data transfer. However, one of the main challenges of terahertz communications is managing and efficiently using the available spectrum.

The team developed the first ultra-wideband integrated terahertz polarization (de)multiplexer implemented on a substrate-free silicon base and successfully tested it in the sub-terahertz J-band (220-330 GHz) for 6G communications and beyond.

Professor Withawat Withayachumnankul from the University of Adelaide’s School of Electrical and Mechanical Engineering led the team which also includes former University of Adelaide PhD student Dr Weijie Gao, who is now a postdoctoral researcher alongside Professor Masayuki Fujita at Osaka University.

“Our proposed polarization multiplexer will enable multiple data streams to be transmitted simultaneously on the same frequency band, doubling the data capacity,” said Professor Withayachumnankul. “This large relative bandwidth is a record for any integrated multiplexer found in any frequency range. If scaled to the center frequency of optical communication bands, such a bandwidth could cover all optical communication bands.”

A multiplexer allows multiple input signals to share a single device or resource, for example data from multiple telephone calls carried over a single wire.

The new device developed by the team allows for doubling the communication capacity with the same bandwidth, while reducing data loss compared to existing devices. It is manufactured using standard manufacturing processes that enable cost-effective large-scale production.

“This innovation not only improves the efficiency of terahertz communication systems, but also paves the way for more robust and reliable high-speed wireless networks,” said Dr. Gao.

“As a result, the polarization multiplexer is a key element to harness the full potential of terahertz communications, enabling advances in diverse areas such as high-definition video streaming, augmented reality and next-generation mobile networks such as 6G.”

The challenges addressed in the team’s work, which they published in the journal Reviews of lasers and photonic devices significantly advance the practicality of photonics-based terahertz technologies.

“By overcoming major technical hurdles, this innovation is expected to spark renewed interest and research activity in this field,” said Professor Fujita, a co-author of the study. “We anticipate that within the next one to two years, researchers will begin exploring new applications and refining the technology.”

Over the next three to five years, the team expects to see significant advances in high-speed communications, leading to commercial prototypes and early-stage products.

“Within a decade, we expect widespread adoption and integration of these terahertz technologies across various industries, revolutionizing areas such as telecommunications, imaging, radar and the Internet of Things,” said Professor Withayachumnankul.

This latest polarization multiplexer can be seamlessly integrated with the team’s previous beamforming devices on the same platform to achieve advanced communication functions.