Could the ubiquitous USB cord soon become an endangered species? With several companies introducing efficient, affordable solutions for power-at-a-distance charging systems, consumers and commercial users may indeed be able to “cut the cord” on their wearable devices and mobile electronics.
Unlike the current generation of magnetic near-field wireless charging systems that require the cell phone or tablet to be in very close proximity to an inductive transmitter, far-field systems transmit radio waves which are collected and converted back to useable DC power by a receiver in the target device. Most far field systems operate in the 915-MHz ISM band that does not require licensing for users but requires that products comply with FCC regulations for non-interference with other devices using the band. Powercast and Energous are two of the first companies to announce FCC-certified solutions for wireless charging.
Powercast’s PowerSpot system uses Direct Sequence Spread Spectrum (DSSS) modulation for power and Amplitude Shift Keying (ASK) modulation for data, and includes an integrated 6dBi directional antenna with a 70-degree beam pattern. The company will begin production of its standalone PowerSpot charger now that it is FCC approved and is also offering a PowerSpot subassembly that consumer goods manufacturers can integrate into their own products. Powercast will unveil its FCC-approved (Part 15, FCC ID: YESTX91503) and ISED-approved (Canada IC: 8985A-TX91503) three-watt PowerSpot® transmitter which works in the far field (up to 80 feet) for over-the-air charging of multiple devices at the upcoming Consumer Electronics Show.
Energous’ WattUp Mid Field transmitter can deliver power via radio frequency (RF) energy to several WattUp-enabled electronic devices at a distance of up to 15 feet. The technology can also support contact-based wireless charging for faster, higher-powered energy transfers. The WattUp system operates under Part 18 of the FCC’s rules that permit higher-power operations than are permitted under the Part 15 rules that other at-a-distance charging solutions operate under. Similar to WiFi, the WattUp ecosystem ensures interoperability between receivers and transmitters, regardless of the manufacturer, making the entire ecosystem flexible and accessible for consumers and manufacturing partners. Energous also offers a far-field version of its WattUp technology. Dialog Semiconductor, for example, is the exclusive component supplier of Energous WattUp transmitter and receiver ICs, and has invested $25 million into Energous over the past year.
Several other semiconductor companies have introduced components that support wireless charging. Infineon, for example, has introduced a series of semiconductors and reference designs for both inductive and resonant wireless charging solutions for the car, at home or in public places. The solutions include in-cabin wireless charging systems for automotive applications and a scalable architecture can support everything from a fast charge smartphone, to a 20 W robot, up to a 60 W drone and beyond. Additional information on Infineon’s wireless charging solutions is available at www.infineon.com/wirelesscharging.
In addition, Powercast and Microchip have teamed to create a low-cost wireless charging development kit. The video below provides an overview of its capabilities and applications.
