Combining power to operate equipment, as well as delivering substantial data rates that are good enough for video — in the same piece of radio kit — is now obtainable, scientists say.
The developing system works similar to how charging pads provide power to a toothbrush or a mobile phone without having to be connected through wires. However, in this case, the apparatus doesn’t need any physical contact with the device and data can be sent at the same time.
Magnetic fields are being used to transmit power through the air, North Carolina State University researchers say in a press release.
The radios used in those devices operate with narrow bandwidth antennas that were thought couldn’t handle data at the same time. (A second sending and receiving radio has to be incorporated. That adds to the weight, bulk and cost — three things that adversely affect take-up.)
However, the North Carolina State scientists say that premise isn’t correct. While you do indeed need ultra-narrow bandwidth antennas, you can actually push more bandwidth down them than anyone previously thought. And they say they’ve proved it, publishing their findings in a paper in IEEE Antennas and Wireless Propagation Letters — “Ultra-high Data-rate Communication and Efficient Wireless Power Transfer at 13.56 MHz.”
“We’ve shown that you can configure a wide-bandwidth system with narrow-bandwidth components,” says David Ricketts, associate professor of electrical and computer engineering at North Carolina State and an author of the paper.
High data rates can be achieved, the researchers claim. They say they have attained 3.39 Mbps throughput — enough for video. Additionally, enough power to operate a Netflix-displaying tablet can be sent at the same time.
In the tests, the tablet was placed about six inches from the transmitter, and three watts was beamed over with little inefficiencies. The team lost only 2.3 percent of the power sent when adding the media stream. They used 13.56 MHz.
“Our system is comparable in power transfer efficiency to similar wireless power transfer devices,” Ricketts says. But “streaming a movie on Netflix” is achieved, too, he says.
Growing interest in wireless power transfer
Wireless power transfer (WPT) is seeing a surge in interest as we gear up for a future of ubiquitous electric vehicles and Internet of Things (IoT) devices, all of which need convenient powering. Consequently, many technologies are being conceptualized and tried, with differing use cases: microwave, for example, for space-based solar power, where power might be collected optically from barrier-free outer space and beamed to spacecraft is one.
End-games for a power/data combo over distance might be similar to that found in wired Power over Ethernet (PoE), where power is sent along the same Ethernet cable as data, making for simple one-wire provisioning — in this case, over the air.
Power-beaming, long-distance WPT, such as what might one day be used to power airborne drones, for example, could benefit from simultaneous data transmission in the same space- and weight-saving radio equipment package.
Communicating between a source and load is also a potential use for a communicating version of WPT. That’s where the power-delivering apparatus, such as a charger, communicates details to a portable device about its status. For example, a battery supplying power wirelessly could broadcast elaborate algorithmic data about its remaining capacity wirelessly in the same radio.