Both Inductive and Resonant technologies use coils of wire to transfer power while RF uses radio frequency. There are also differences in the transmission frequencies and communication protocols, which translate into variations in spatial freedom to support multiple use cases.  For example, Resonant coils are tuned for better efficiency and enable spatial freedom while Inductive requires the device to be attached to the charge.

Resonant charging utilizes uniquely designed coils to allow movement over longer distances while charging. With resonant charging, any enabled surface can power a device, up to 50mm height and from a wide surface area. 

Resonant-based chargers inject an oscillating current into a highly resonant coil to create an electromagnetic field. A second coil with the same resonant frequency receives power from the electromagnetic field and converts it back into an electrical current that can be used to power and charge devices.

This lets you transfer power over longer distances and does not require exact orientation. Learn more about AirFuel Resonant technology. 

RF charging uses a radio frequency transmitter and a receiver embedded within the device (not a coil) to pick up RF energy and convert it to power. RF provides low power at distances ranging from a few centimeters to a meter, delivering true spatial freedom. This means it works well with wearables, medical devices or other devices that need the broadest spatial freedom. Learn more about AirFuel RF technology.

Inductive charging uses closely coupled coils to deliver transfer of a magnetic field over a short distance (up to 20mm). It works well for devices that can be placed directly on top of the charging source (i.e., with no spatial freedom) such as a smartphones on top of a charging pad.

We provide technical requirements, specifications and guidelines that members can use to ensure wireless charging products (based on the same technology) interoperate with one another and that wireless power technology is high quality, safe and reliable. The Alliance and its members also work to promote wireless charging and raise worldwide awareness of its many benefits for consumer and commercial use. We continually listen to the needs of the market and actively support a range of wireless power technologies that will deliver the best experience and realize our vision of a world without wires.