The surface of the antenna is composed of an artificial thin-sheet material with sub-wavelength thickness that can be changed by switching the meta-atoms on its surface between radiating and non-radiating states. This process is equivalent to turning on and off switches by controlling the electric current.
This allows the surface of the antenna to achieve complicated radio wave manipulation through software control, including highly directed beams.
"The concept provides an analytical approach to synthesise antennas with the desired radiation patterns for different specific uses by simply changing the antennas' shape and structure," said researcher Dr Wu Gengbo.
The antenna relies on the successful combination of two research advances, namely amplitude-modulated (AM) leaky-wave antennas and space-time coding techniques.
The time modulation of electromagnetic waves on surfaces like that created for the antenna usually generates unwanted harmonic frequencies, called sidebands. These sidebands carry part of the radiated electromagnetic wave energy and interfere with the useful communication channels of the antenna, leading to "spectrum pollution".
But the researchers proposed a design which successfully suppressed the undesired harmonics, achieving a high-directivity beam and enabling secure communications.
"With the AM leaky-wave antenna and space-time coding technologies, we achieve the designated radiation characteristics by controlling the on-off sequences and duration of the 'switches' on the antenna through software," said Professor Chan Chi-hou.
The energy from the radiated beam of the antenna can be focused to a focal point with fixed or varying focal lengths, which can be used for real-time imaging and treated as a type of radar to scan the environment and feed back data.
Professor Chan said he believes the technology will play "an important role" in future 6G wireless communications.
"For example, the radiated beam can scan a person and create an image of the person, allowing mobile phone users to talk to each other with 3D hologram imaging. It also performs better against eavesdropping than the conventional transmitter architecture," he said.
Last month, Ericsson announced plans to build a multi-million-pound research centre in the UK that will focus on developing future 6G networks.
Scientists at the Korea Institute of Materials Science recently revealed a new magnetic material that can absorb the kind of ultra-high frequencies that could be leveraged by 6G technologies.
