Philips "will be one of our first customers to ship in volume later in 2007," said Keith Kressin, vice president of Powercast (Ligonier, Pa.) . The company claims its Powercaster and Powerharvester modules can recharge batteries in consumer devices smaller than a cellphone using RF broadcasts from up to a meter away.

Using the 900-MHz band, Powercast transmists RF energy to a receiver module measuring about half the size of a AAA battery. In beta testing of a wireless sensor network at the Pittsburgh zoo, the Powerharvester receiver module was retrofitted to the battery compartment of a wireless sensor made by Intellisensor (Pittsburgh), extending battery life from under 120 days to several years.

The modules "have been wirelessly keeping the batteries of the zoo's temperature and humidity sensors charged at 100 percent despite occasional disruptions in the power beam which is located about 30 feet away from the wireless sensors," Kressin said.

The undisclosed Philips consumer device that will use the modules includes an omnidirectional power beacon that will operate over a distance of about 1 meter to recharge devices within that range. During beta testing, a directional antenna was used so that the power beacon could be located 30 feet away.

Kressin said Powercast's technology "is not dependent on any particular radio technologies; we can use almost any 900-MHz transmitter or receiver."

RF power transmissions typically deliver milliwatts of power to devices using up to 4 volts, making it ideal for recharging small batteries in remote controls and flash-memory based devices like iPods. Powercast said medical implants will also begin using its wireless energy transfers this year. Cellphones are also a candidate, but current Powerharvester modules can only recharge about half the capacity of a typical cellphone battery.

Powercaster said it has received FCC approval for its technology, which includes a family of energy beacon transmitters and receivers. Development began in 2003.

Powercaster's technology is unrelated to wireless power beacon developments by the Massachusetts Institute of Technology which use a proprietary beacon and resonant antenna scheme.