Charging Electronics via Radio Waves May Be Possible

Radio frequency (RF) charging completely ditches the need for cables or plugs—which could lead to truly wireless charging for all sorts of small electronic devices.

Not to be confused with inductive/wireless charging, which requires a charging pad or dock, RF charging utilizes an embedded antenna to convert low-level radio waves into energy. Samsung is already using it with the remotes for its new 2022 Smart TVs, though they can also charge via solar energy or USB-C. In theory, this creates a scenario where the remote will never truly run out of power. But why stop at remotes? Could RF charging be used for other small electronic devices that require relatively modest amounts of power?

"It is highly possible to see this kind of technology extend beyond Samsung's Smart TV remotes into the broader consumer market," agreed Stephen Curry, CEO of digital signature service CocoSign, in an email to Lifewire. "Companies like Powercast have been approved for long-range wireless charging using 915-MHz industrial, scientific, and medical equipment to broadcast RF energy to compatible devices."

The Possibilities

TV remotes don’t generally use much power—usually less than 2V—so using RF charging to keep it powered up seems fairly reasonable. Especially when looking at examples of RF receivers, which can output between 4.2V and 5.5V, plenty of power for a standard TV remote. This could also apply to other small electronics that might be kept near a Wi-Fi router, such as game controllers or possibly even smartphones. 

"Using radio waves to charge such devices is a great idea and would be feasible since they are low-powered devices and since that energy goes to waste otherwise," said Curry. "Regarding hardware compatibility, RF charging is not limited by physical limitations and shape as developers can build the receiver in smaller devices."

So RF charging could physically work with most small electronic devices since the only real challenge would be to hook up a receiver. But as Curry points out, widespread use of RF charging could also significantly impact our relationship with these devices. We wouldn't have to deal with cables or even have to look for charging stations in the first place. And, since it's just using radio waves, multiple devices could be charged simultaneously.

"The widespread adoption of wireless charging technologies like RF charging would improve the workplace," Curry stated, "by offering proper mobility and eliminating low-battery anxiety associated with charging cords."

The Limitations

In its current state, RF charging still has some drawbacks—aside from not being able to power larger devices, that is. As Tian notes, the use of low-frequency radio waves as a means of energy limits the amount of power that can be converted. So while it won’t require cables or an induction pad, it also won’t charge devices as quickly as either option.

"The radio waves consist of low frequency, due to which they can't transfer extensive data or energy at one time," said Jonathan Tian, Co-Founder of smartphone solution provider Mobitrix, in an email to Lifewire. "Due to this, the speed of charging will be very low in comparison to the charging via ultrasound waves."

According to Tian, cost is another hurdle RF charging still has to overcome. More specifically, it would cost users more money to charge more complex devices (like smartphones) with radio waves. This means it might be some time before we see the technology appear in more typical consumer electronics.

"Using radio waves for charging is too expensive compared to wired charging," Tian stated. "One has to pay about 50% more to charge their device using radio waves. However, Radio waves also consume 50% more energy than ultrasound waves [as with induction charging]."

As promising as RF charging might be, it will probably take some time for it to become more common in consumer-level devices. After all, for as prevalent as something like Qi wireless charging has become, it didn't get to be that way overnight. It took years of development and adoption from multiple hardware companies. RF charging might also get to that point, but we're probably going to have to wait a while longer.