A breakthrough in antenna technology that could revolutionise the future of wireless communications, particularly for the upcoming 6th generation (6G) networks, has been announced by a research team led by Professor Chan Chi-hou, Chair Professor of the Department of Electrical Engineering at City University of Hong Kong (CityUHK).

The study, "A synthetic moving-envelope metasurface antenna for independent control of arbitrary harmonic orders", was recently published in Nature Communications.

The team developed a novel metasurface antenna capable of simultaneously generating and controlling multiple frequency components through software. This major advancement promises to enhance the efficiency and capabilities of wireless communication systems.

Traditional antennas are typically fixed in their capabilities. To enhance antenna flexibility and control, the researchers proposed and experimentally demonstrated a novel antenna concept called a "synthesis moving envelope". This groundbreaking technology allows antennas to simultaneously generate arbitrary harmonic frequencies and their wave properties to be controlled through software manipulation.

Notably, this is the first-ever reported antenna with such capabilities, marking a milestone in antenna design. The technology has potential applications in next-generation large-capacity and high-security information systems, real-time imaging, and wireless power transfer.

The antenna can simultaneously transmit multiple signals to users in different directions, substantially increasing channel capacity. Moreover, the integration of sensing and communications, crucial for 6G wireless networks, is significantly advanced by this innovation, which has far-reaching implications for future communication systems.

"The proposed synthesis approach promotes the metasurfaces' spectral controllability to a new level," explained Professor Chan, who is also Director of the State Key Laboratory of Terahertz and Millimeter Waves (SKLTMW). "The unparalleled frequency controllability, together with its highly straightforward coding strategy (1-bit), sideband-proof, and potential for on-chip integration, provides a proposed metasurface antenna that goes beyond existing technologies, offering promising potential in wireless communications, cognitive radar, integrated photonics and quantum science," echoed Professor Wu Gengbo from the Department of Electrical Engineering and a member of the SKLTMW.

The research is a joint effort between CityUHK and Southeast University, Nanjing, China.

Professor Wu and Dr Dai Junyan, a former postdoctoral fellow at SKLTMW, are the co-first authors. Academician Cui Tiejun and Professor Cheng Qiang, both from Southeast University, as well as Dr Dai and Professor Chan, are the corresponding authors. Other authors include Dr Shum Kam-man and Dr Chan Ka-fai, Senior Engineers with the SKLTMW.

The research was supported by grants from the Hong Kong Research Grants Council and the Shenzhen Natural Science Foundation Program.