Using RF energy to actually power something

Countless tech-oriented companies concentrate on solutions for new and emerging technologies. Powercast LLC, a small startup in Ligonier, Pa., stands out due to its technology platform that harnesses radio frequency (RF) energy and uses it to power or even recharge devices.

Known as the Powercast Wireless Power Platform, it takes old reliable RF to new, more useful levels. By using the technology, the RF waves already moving through the air can be harnessed to power devices and to recharge batteries continuously. The system consists of two components: a transmitter and a receiver.

Powercast was chosen “Best of Show for Emerging Technologies” at the 2007 International Computer Electronics Show (CES). The award was given for Powercast’s use in consumer electronics applications; however, the application potential is almost limitless, according to Keith Kressin, executive vice president, sales and marketing, Powercast.

The CES demonstration showed how the technology, by using a lamp, could produce a milliwatt of power that spreads out in a 1-meter radius. This is the consumer-oriented element, and in the CES demo, the energy powered up devices such as cell phones and game controllers.

“The specific lamp we used had an embedded transmitter [Powercaster] that transmitted a specific RF signal. The surrounding devices using our Powerharvester circuit were subsequently charged,” Kressin said.

Perhaps the biggest aspect of the technology, the breakthrough part, is this harvested energy can now be sent over distances never before achievable. According to Kressin, the distance can be 30 feet or more, depending on the application and environment. Because of this, Kressin sees limitless potential for the technology to be used in places such as hotels, security centers, stadiums and arenas.

In theory, the potential range of the technology seems almost limitless. For example, in a built environment, you could send power to fixed sensors using the technology. Under traditional power scenarios, power would need to be hardwired, which ultimately costs more money and limits location. For building applications, this means the technology could provide a continual trickle of energy to recharge device batteries, which essentially would put an end to battery replacement and downed devices.

This technology holds additional promise for lighting applications. In fact, RF energy could help create designs never before achievable. This also would apply to heating, ventilating and air conditioning. Generally, one would have one thermostat in a room, but by using the Powercast technology, a residence could have many spread throughout without the need for additional wires to support them.

“You could place one transmitter in the corner of a room and remotely power multiple sensors for better environmental control,” Kressin said.

The technology seems perfect for new home construction. According to Kressin, new homebuilders have been contacting his company regarding the technology.

“For new home construction, you would need to build in transmitters to provide RF energy to be harvested. That RF could be used for the infrastructure [e.g. HVAC, security, lighting, etc.] or to even power consumer devices in targeted areas. Of course, the consumer devices would need our technology embedded as in one of our Powerharvester circuits,” Kressin said.

The Pittsburgh Zoo and PPG Aquarium are serving as a beta testing site. A wireless sensor network keeps batteries charged, extending their lives. This has proven beneficial in maintaining the stringent environmental conditions required for the safety of the zoo inhabitants.

This technology is a viable solution of both residential and commercial facilities, according to Kressin. Understanding the technology should come easily to most electrical contractors, as they have watched the build environment slowly morph into and accept the future of wireless applications.         EC