Though the WPC and Qi are currently synonymous with inductive charging, the WPC also demonstrated resonant technology at the 2014 International CES. Dubbed WoWz, the technology is backward compatible with Qi and charges at a distance of up to 18 mm with 65% charging efficiency.
"Samsung has Qi phones out there today and is also an investor in a company that is developing resonance technology that is in WPC," Perzow said. "It's reasonable to guess that Samsung will have resonance technology in their phones." A WPC member and phone maker will debut a PMA+Qi compatible wireless charging system in 2014. He expects more bridge products in the coming years. "For a short term, it can work, but as soon as one standard can develop significantly, it's going to be impossible for that approach to work."
MediaTek, a member of WPC and PMA (now in partnership with the A4WP) debuted its own wireless charging technology at the CES -- a dual-mode charging solution that supports Qi and resonance. The system is a stand that can hold and charge the equivalent of two smartphones. It's built over a single coil and single IC, with a target segment of mobile applications in the rante of 1/2 Watt to 15 Watts.
On the left (in red) is a wireless charging station based on resonant power transfer technology. On the right is Qi wireless charging station using industive power transfer technology.
(Source: EE Times/Junko Yoshida)
"The device is smart enough to figure out which charger it is, and then it charges appropriately. [The technology] goes into virtually anything you want from a Bluetooth headset to an electric vehicle," Mark Estabrook, director of strategic marketing at MediaTek, told us. "This is something of a bridge product, we think, meaning we think it will help get the industry from where it is today -- the inductive -- to the resonant technology which will be developed over the next 2-3 years."
Mark Hunsicker, senior director of product management at Qualcomm and a treasurer for the A4WP, said there is an opportunity for a dual-mode bridge transitional receiver that implements inductive and resonance charging. There's not much legacy product in the marketplace.
Nevertheless, "I'm not a big fan," Hunsicker said. "It's not a highly desirable solution from the consumer side, because there's not a great deal of commonality between the two technologies. There are increased materials and area costs, because there's not a lot of synergy between the two technologies."
Mohit Bhushan, US marketing manager at MediaTek, told us his company is working on resonance solutions to complement future generations of its recently released LTE SoC.