Tapping Into 5G High-frequency Power
Operating just like an optical lens, the Rotman lens provides six fields of view simultaneously in a pattern shaped like a spider. Tuning the shape of the lens results in a structure with one angle of curvature on the beam-port side and another on the antenna side. This enables the structure to map a set of selected radiation directions to an associated set of beam-ports. The lens is then used as an intermediate component between the receiving antennas and the rectifiers for 5G energy harvesting. This novel approach addresses the tradeoff between rectenna angular coverage and turn-on sensitivity with a structure that merges unique radio frequency (RF) and direct current (DC) combination techniques, thereby enabling a system with both high gain and large beamwidth.
In demonstrations, Georgia Tech’s technology achieved a 21-fold increase in harvested power compared with a referenced counterpart, while maintaining identical angular coverage. This robust system may open the door for new passive, long-range, mm-wave 5G-powered RFID for wearable and ubiquitous IoT applications. The researchers used inhouse additive manufacturing to print the palm-sized mm-wave harvesters on a multitude of everyday flexible and rigid substrates. Providing 3D and inkjet printing options will make the system more affordable and accessible to a broad range of users, platforms, frequencies, and applications.
Replacing Batteries With Over-the-air Charging
“The fact is 5G is going to be everywhere, especially in urban areas. You can replace millions, or tens of millions, of batteries of wireless sensors, especially for smart city and smart agricultural applications,” said Emmanouil (Manos)Tentzeris, Ken Byers Professor in Flexible Electronics in the School of Electrical and Computer Engineering.
Tentzeris predicts that power as a service will be the next big application for the telecom industry, just as data overtook voice services as a major revenue producer. The research team is most excited by the prospect of service providers embracing this technology to offer power on demand “over the air,” eliminating the need for batteries.
“I’ve been working on energy harvesting conventionally for at least six years, and for most of this time it didn’t seem like there was a key to make energy harvesting work in the real world, because of FCC limits on power emission and focalization,” Hester said. “With the advent of 5G networks, this could actually work and we’ve demonstrated it. That’s extremely exciting — we could get rid of batteries.”
Source and top image: Georgia Tech