Magnetic induction charging uses two coils: a transmitter coil and a receiver coil. Alternating current in the transmitter coil generates a magnetic field, which induces a voltage in the receiver coil.

In contrast, resonance charging offers wireless AC transmission to a device at a distance ranging from 5mm to 40 millimeters (about 1.5-in) from the power source.

Resonance charging is based on the same transmitter/receiver coil technology as magnetic induction, but it transmits the power at a greater distance. So, for example, a mobile device could be charged when laid next to a laptop with resonance charging capability.

To date, there are no resonance-charging devices available, according to Stofega. But that may soon change as Intel ramps up its wireless chip development.

Intel Labs first demonstrated in 2008 technology that could wirelessly charge mobile devices. Intel's Wireless Charging Technology (WCT) would let a user charge a smartphone wirelessly from a notebook PC. Intel late last month with Integrated Device Technology Corp. (IDT) to develop chipsets for WCT products.