Wireless power has made significant advancements in the last few years with many inductive technologies becoming mainstream and widely available – notably Qi and PowerMat products. Major players like Samsung are building wireless power receivers into their phones along with a huge number of transmitters widely available from companies like AirCharge, TYLT and of course Samsung themselves. Currently there are nearly 700 different products on the market that are Qi certified alone.
However, inductive wireless charging is not without its limitations – amongst them include slower charging speed and the requirement for precise alignment of the receiver (smartphone) and transmitter (wireless charger). This is where resonant technology can deliver a number of advantages and truly represents the future for charging wirelessly. Unlike inductive technologies, there are still zero finalized resonant products in the marketplace. A4WP has long promised an option and now the Wireless Power Consortium is in the process of developing a resonant specification called Resonant Qi. I’ve been working on the specification personally along with other top member companies at the WPC. The new Resonant Qi specification will overcome existing limitations with Inductive Qi and provide those consumer benefits which OEMs are looking to integrate into their devices.
What’s most important?
The discussion on how inductive and resonant perform must be framed in respect to what is valued by the end user. Specifically, what are the factors that will increase the appeal of wireless charging for the consumer?
Based on the above factors, how do inductive and resonant technologies stack up?
I have used examples of current inductive products that we find on the market today (Qi and PMA) to compare functionality and performance with the Resonant Qi specification, currently in the works – see Table 1 below:
Overall, resonant presents a wireless charging future with greater convenience, performance and flexibility. The main areas where we will see the greatest advantages are:
Resonant Qi technology provides the next evolution to an already widely available set of products. It will provide a noticeable step-up in performance over the current inductive solutions, and will help wireless charging technology become more pervasive. Today, inductive solutions continue to be the only option for consumers wanting to purchase their own wireless charging system despite a lot of noise from other rival resonant standards. One has to ask why there are no (zero!) A4WP products shipping in the market to date.
The key for the WPC, and arguably the industry at large, will be to deliver a Resonant Qi specification that remains fully compatible with the hundreds of millions of existing Qi products on the market, while also delivering greater user performance over inductive systems. This approach puts the consumer first, and the best technologies always do.
Posted on Wireless Power Consortium website
WPC’s v1.1 specification, supported by the largest ecosystem comprising over 200 member companies, enables the most efficient and cost-effective wireless power solutions based on inductive power, close-coupled technology.
WPC’s Resonant Task Force (RTF) will deliver an extension for WPC v1.1 specification for a best-in-class magnetic resonance technology to address applications that require multi-device charging, increased spatial freedom, increased charging at distance (Z-height), and devices that are designed for different power levels.
The RTF has set high goals for backward compatibility to existing v1.1 specification, efficiency, transmitted power, FOD, thermal design, and other critical parameters. Meeting these goals would result in the most advanced and compelling products addressing a broad set of applications such as smartphones, tablets, PCs, wearables, automotive, and infrastructure.
Members saw significant achievements and progress at WPC’s Leeuwarden meeting in June, last month. After hundreds of combined engineering hours by 5 of the world’s leading companies, here’s what happens with an open standards organization when the best minds in the industry collaborate:
Figure 1 – Multiple manufacturers demonstrating Qi1.1 and Qi1.2 resonant systems
Figure 2 – LG v1.2 resonant Tx’s delivering power to v1.1 inductive Rx and v1.2 resonant Rx
Figure 3 – LG resonant Tx delivering power to PowerbyProxi resonant Rx
Figure 4 – Philips resonant Tx delivering power to PowerbyProxi resonant RX at distance of 45mm Z height
Figure 5 – Convenient Power Tx delivering power to PowerbyProxi resonant RX at distance of 18mm Z height
The plug-fest was festive indeed!
The WPC is an open standards organization enabling the use the best ideas from any company. That’s why Qi sets the standard for wireless power transfer.
Chairman of the Resonance Taskforce