A US patent granted to Apple this week shows that its engineers are experimenting with wireless charging, a feature that's found its way to many phones and tablets but not Apple's iPhones and iPads.

The patent, spotted by Apple Insider, would deliver power using signals in the 2.4GHz and 5GHz bands, among others. Those frequencies are the same ones used by Wi-Fi routers, which means Apple's invention could pave the way for your phone to charge wherever there's a strong-enough Wi-Fi signal. Once your phone gets enough juice, it could also provide power to other devices around it using the same frequencies.

Like all patents, there's little chance of this technique showing up in consumer devices in the immediate future, nor is there a guarantee it will ever make it to market. But Apple appears to be preparing for the long-term future, because it notes in the patent filing that the power signals could also come from millimeter wave antennas, which make extremely high-frequency transmissions.

Many companies, including Facebook and Verizon, are eyeing millimeter wave antennas as a way to blanket cities with super-fast internet without having to spend large sums on new fixed infrastructure. Verizon is planning a 5G home router, for example, that could be an ideal delivery vehicle for Apple's wireless charging signals.

Apple's patent was awarded a little more than a month after Sony received one for a similar wireless charging concept, which envisions charging antennas embedded in a wide variety of consumer devices. Wireless charging ideas also seemed to be everywhere you looked at this year's CES, some of which could even charge cars.