Far-field wireless power far from far fetched

All over CES last week, and the rest of the world every day, folks were scrambling to find an open AC outlet to recharge their smartphones, or to find fresh batteries for their battery-powered gear.

This AC outlet scrambling could soon end. At CES, at least four companies  — Energous, Ossia, Powercast and Wi-Charge — demonstrated, and got ready to license and market, so-called "far-field" wireless power transmission ecosystems, capable of transmitting 1 to 3 watts up to a dozen feet away.

See: Wireless Charging At CES 2019: Hype or Real — Or Just Not This Year?

Far-field wireless power transmission systems operate similarly to Wi-Fi. A transmitter transmits an RF signal that is transformed into DC power via a converter chip to continually trickle charge low-power devices such as smartphones, Bluetooth headphones, gaming, VR and TV controllers, wearables, wireless keyboards and mice, smart home gear such as Wi-Fi cameras, sensors and smart locks. In a few years' time, the hope is to make far-field wireless power as ubiquitous as Wi-Fi is now, in homes as well as public spaces, ending today's scrambling search for an AC outlet.

What's the catch? Each of the four aforementioned far-field wireless vendors insist its scheme is superior. Without a clear early and dominant system, or an independent entity to force the four to collaborate and create a single standard, a lengthy, potentially expensive and category debilitating far-field wireless charging war is likely, a loss for the wireless power vendors, their CE product partners and especially consumers.

See: Big Problems With Power-At-A-Distance

At CES, each of the four far-field wireless transmission providers presented slightly different technological and market approaches.

Energous/Dialog

SK Telesys's Delight hearing aid can be recharged on Energous's WattUp near-field charging matt.

SK Telesys's Delight hearing aid can be recharged on Energous's WattUp near-field charging matt.

Energous shared appointment-only suite space with Dialog, the fabless company manufacturing and selling the ICs powering Energous' WattUp Wireless 2.0 system. WattUp will be rolled out in three phases: right now, a "near-field" Qi alternative without Qi's location-specificity; later this year a "desktop" so-called mid-field system that will transmit power up to three feet away; and, in 2020, a far-field system with a range of up to 15 feet.

Related: FCC Approves Energous's 'Power-At-A-Distance' Charging Tech

Dialog showed its new 1.7mm x 1.4mm DA2223 RF-to-DC chip, the tiny chip inside the first WattUp-enabled product, a hearing aid from SK Telesys that can be recharged simply by placing it on a WattUp near-field charging matt.

Ossia

Ossia is developing two systems, both under its Cota brand. Its 2.4GHz system will deliver less than a watt — "just enough to keep a smartphone happy," according to Ossia chief technology officer and founder Hatem Zeine — and at 5.8GHz for longer-distance usage cases.

Ossia's three-in-one iPhone sleeve prototype.

Ossia's three-in-one iPhone sleeve prototype.

At Ossia's booth and suites, the company demonstrated prototypes of three-way Qi/Cota/battery iPhone X and Xs sleeves, as well as continually charging Cota Forever AA and AAA batteries.

Powercast

Powercast's power Grips for Nintendo can be wirelessly recharged by a PowerSpot transmitter.

Powercast's power Grips for Nintendo can be wirelessly recharged by a PowerSpot transmitter.

Powercast has developed a sort-of "mid-field" wireless power system at 915MHz that can transmit around 1 watt up to two feet away, designed more for recharging than trickle charging. In 2010, the company unveiled its PCC100 RF-to-DC chip primarily for industrial applications, but the company is now marketing the IC to CE device vendors.

Late last year, the company started selling its PowerSpot transmitter ($99), and at CES Powercast showed Grips, a holder with an imbedded battery to power the Nintendo Switch Joy-Con controller. Grips can supply up to 38 hours of game play, then can be recharged simply by placing it within a couple of feet of the PowerSpot.

Wi-Charge

Kube Systems's Beam charger employs Wi-Charge's IR technology.

Kube Systems's Beam charger employs Wi-Charge's IR technology.

This company is an outlier in the far-field wireless power field — its system operates on IR rather than RF, which means its transmitter and device/receiver have to be able to "see" each other. At CES, Wi-Charge demonstrated several far-field wireless power reference designs: 1- and 3-watt transmitters; a Wireless Power Kit with a transmitter and a cradle to provide wireless power to an Amazon Dot or a Google Chrome Home Mini; a wireless Qi charging cradle designed to be attached to tables or countertops in restaurants or other public spaces; a smartphone charging dongle; wireless lighting; and, smart home devices charged from a transmitter embedded in a lighting fixture.

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