CityUHK Scientists Pioneer Next-Generation Radar for 6G Networks

In a breakthrough in radar technology, researchers from the City University of Hong Kong (CityUHK) have developed the world's first integrated photonic millimeter-wave radar chip, achieving unprecedented precision in a remarkably compact device. This breakthrough represents a significant step forward in the development of Integrated Sensing and Communication (ISAC) networks, paving the way for more sophisticated and capable 6G technologies.

Millimeter-wave radars are poised to play a pivotal role in the forthcoming 6G era, enabling high-resolution environmental sensing from any connected device. While traditional electronic radars have faced a long-standing trade-off between frequency and bandwidth, the team has developed a breakthrough solution. In their innovation, electronic radar signals are generated and processed in the form of optical signals, taking advantage of the broad operation bandwidth inherent to optical systems. It also leverages state-of-the-art integrated photonic technologies to shrink the core system to a size smaller than a coin.

"This work demonstrates the first integrated photonic radar that can operate in the millimeter-wave bands, with the highest resolution among all on-chip photonic radars to date," says Professor Cheng Wang from the Department of Electrical Engineering at CityUHK who led the research. "It marks an important milestone in the development of photonic radar technology."

Operating in the millimeter-wave V band (centered at 45 gigahertz) with a 10 gigahertz bandwidth, the system delivers exceptional precision for ranging, velocity detection, and inverse synthetic aperture radar (ISAR). The technology's breakthrough lies in its integration of both signal generation and the processing of target echoes on a single chip. This design significantly alleviates the need for expensive high-speed digital-to-analog (DAC) and analog-to-digital (ADC) converters. The integration is made possible through an innovative thin-film lithium niobate photonic platform, which the CityUHK scientists have refined through years of research.

The team's innovation extends beyond technical performance to practical implementation. They have developed a cost-effective solution that can be mass-produced on a 4-inch wafer scale, making it commercially viable for widespread adoption in future wireless networks. “The forthcoming 6G networks require not just increased data throughput, but also the ability to perform high-resolution sensing of the environment," explains Professor Wang. "Our solution provides high-resolution and real-time situation awareness, opening up new possibilities for indoor sensing, automated driving, and vital-sign monitoring."

 

The research, titled "Integrated lithium niobate photonic millimeter-wave radar," was recently published in Nature Photonics. Professor Sha Zhu from Nankai University and Yiwen Zhang, PhD student at CityUHK are the co-first authors. Professor Cheng Wang, Professor Edwin Yue-bun Pun, CityUHK and Academician Ning Hua Zhu from Nankai University are corresponding authors. Other collaborators include Dr. Hanke Feng and Yongji Wang from CityUHK, Jiaxue Feng from Beijing University of Technology and Kunpeng Zhai from Institute of Semiconductors, Chinese Academy of Sciences.

For inquiries, please contact Professor Cheng Wang, the Department of Electrical Engineering at CityUHK, by email at cwang257@um.cityu.edu.hk.