September 2001

Power Miser

By Technology Review

Wireless networks that give you access to e-mail or the Web from anywhere in your home or office are, it seems, becoming ubiquitous. But the electronic receivers that allow laptops and personal digital assistants to pick up wireless data signals are power hogs, reducing the already short battery life of portable computers. University of Southern California electrical engineer Anthony F. J. Levi has developed a receiver that he says could extend battery life as much as tenfold.

The key is a microphotonic disk that converts the microwaves used by these wireless networks into light waves. This low-loss optical signal is easily converted to electronic form using existing low-power technology. (Conventional all-electronic microwave receivers must consume lots of power to prevent signal loss.) While the new receiver is still in the lab, Levi expects commercial applications to emerge by year's end.