'Improved' wireless communication systems come closer to reality

A team of scientists has paved the way for ultrafast and reconfigurable on-chip wireless communication systems with unmatched advantages in compactness, low power consumption and low fabrication complexity.

Researchers from the University of Sydney made a breakthrough achieving radio frequency signal control at sub-nanosecond time scales on a chip-scale optical device.

Radio frequency (RF) is a particular range of electromagnetic wave frequencies, widely used for communications and radar signals. The work should impact the current wireless revolution.

Lead author Yang Liu said the new research that could unlock the bandwidth bottleneck faced by wireless networks worldwide was undertaken at the headquarters of the Australian Institute for Nanoscale Science and Technology (AINST), the 150 million dollar Sydney Nanoscience Hub.

"Nowadays, there are 10 billion mobile devices connected to the wireless network (reported by Cisco last year) and all require bandwidth and capacity," Liu noted, adding "By creating very fast tunable delay lines on chip, one eventually can provide broader bandwidth instantaneously to more users. The ability of rapidly controlling RF signal is a crucial performance for applications in both our daily life and defence."

"For example, to reduce power consumption and maximize reception range for future mobile communications, RF signals need to achieve directional and fast distributions to different cellular users from information centres, instead of spreading signal energy in all directions," he continued.

The lack of the high tuning speed in current RF technique in modern communications and defence has motivated the development of solutions on a compact optical platform.

These optical counterparts had been typically limited in performance by a low tuning speed on the order of milliseconds (1/1000 of a second) offered by on-chip heaters, with side effects of fabrication complexity and power consumption.

"To circumvent these problems, we developed a simple technique based on optical control with response time faster than one nanosecond: a billionth of a second, this is a million times faster than thermal heating," said Mr Liu.

Co-author Benjamin Eggleton said the technology would not only be important for building more efficient radars to detect enemy attacks but would also make significant improvements for everyone.

The study appears in journal Optica.