January 12, 2018
By Tiernan Ray
Wireless power, the ability to deliver electricity to gadgets without plugging those gadgets into a cable, is a hotbed of innovation at the moment. The dominant standard, called “Qi,” is ever under attack from other efforts.
This week saw interesting developments from Energous (WATT), which aims to transfer power via radio frequency transceivers, with limited results so far, and some controversy about its business.
There are other contenders. On Wednesday in Las Vegas, during the Consumer Electronics Show, I met with Alex Lidow, who is founder of a privately held chip company EPC of El Segundo, California.
Lidow is a figure out in the history of semiconductors. I first profiled him in these pages on June 29th of 2016. He is responsible for the invention of the "power MOSFET" in 1977, a device that went on to be the basis of billions in semiconductor sales.
At EPC, Lidow is trying to replace silicon, one of the most prevalent types of semiconductor around, with a different material, Gallium Nitride, commonly abbreviated as GaN — or “eGaN,” as Lidow calls the company’s new, improved form of GaN.
And one market for GaN is for power applications such as "magnetic resonance." Magnetic resonance is a cousin to the "magnetic inductance" used by Qi. However, it's believed that with resonance, one can achieve greater distances and greater power. One of EPC's customers is startup Witricity, which hasn't gained much traction so far.
One stumbling block for everyone has been how to have large surface areas for charging. An issue is that many coils need to be combined together to cover an area. This is one challenge for Apple (AAPL) with its promised "AirPower" mat for Qi charging, which is supposed to come out this year.
Several individuals I spoke with at the show this week expressed the notion that Apple is struggling with basic issues, such as the coil placement, though I can't be certain that's true.
A general issue with using magnets, in magnetic resonance, for example is that as you try to make the charging area bigger and bigger, "you've got waves spreading out from the surface and it interferes with things in the surrounding area."
To help solve that, so that he can sell more GaN chips, Lidow and his team at EPC have hit upon something most intriguing: A large, flat antenna that can be built into surfaces of many sizes.
"With this, you get an even magnetic field and you it doesn't spread beyond the charging area in a way that would affect devices around it."
He also held up a tray with a wood veneer, measuring 21 by 11 inches. Underneath the wood veneer is a kind of honeycomb of interlocking magnetic elements spanning the length of the tray, as you can see in the photo at the top of this post. One small circuit board on one side has GaN chips to power that large antenna.
Using a big antenna, GaN can deliver potentially hundreds of watts of power across the surface of something like this. Lidow demonstrated putting multiple objects on the tray, retrofitted with the magnetic receiver, at the same time, with arbitrary placement -- a lamp, a baby monitor, a speaker a smartwatch -- to show how resonance can juice up several things just by putting them down on the surface.
The same kind of thing can be built into other objects, such as a desk. Now all Lidow needs is a party to build this, and buy his GaN chips for it, and get it out into the market.