A 3D stack of reflecting mirrors on a microchip could triple the data speed of wireless links, accelerating the development of 6G communications, according to new research.
Most current wireless communication technologies, such as 5G cellular, operate at frequencies below 6 gigahertz. To further increase data rates, researchers are working on developing 6G communications, which would use frequencies above 20 GHz and deliver data rates 100 times higher than 5G.
But at the higher frequencies expected for 6G, transmissions are also more susceptible to environmental attenuation and loss. That’s why most 5G and 6G technologies use arrays of antennas, rather than relying on a single transmitter and single receiver. These arrays must precisely control the delay that a signal may experience, to ensure that it arrives at the right time, without being scrambled. But the components that add the necessary delay to the signal can themselves cause problems.
The most common delay element is a phase shifter. These components can be smaller than 0.3 square millimeters, but they can’t delay all frequencies equally across a wide bandwidth, says Bal Govind, a doctoral student in electrical and computer engineering at Cornell University in Ithaca, N.Y. Phase shifts can smear the signal, severely limiting the data rate of a wireless network, Govind said.
In contrast, true time-delay elements can delay all frequencies equally over a wide bandwidth, avoiding the blurring problem. But such elements are physically very large, typically measuring one to two square millimeters, Govind says. This means that only a few circuit components can be integrated onto a chip, limiting channel capacity.
But now Govind and his colleagues have developed a way to miniaturize true time-delay elements: The new microwave component is just 0.16 square millimeters in size, smaller than a phase shifter, but it can also operate like a true time-delay element over a 14 GHz bandwidth.
Scientists achieved these benefits using 3D spiral mirrors: the signal wraps around in three dimensions within these vertical stacks, introducing delays. At the same time, the 3D nature of the design allows components to be placed more closely together, saving space.
“Typically, true time delay is very expensive in terms of chip area,” Govind said. “We provide a solution to this.”
Overall, the researchers estimate that an array of their new devices operating within an 8GHz bandwidth could achieve data rates of more than 33 gigabits per second — three times faster than phase shifters and more than 40% faster than real time-delay elements. The researchers add that their strategy could also be extended into the optical and acoustic domains.
The scientists detailed Their findings This week’s journal Nature.
From an article on your site
Related articles from around the web
