Software-Defined Radio Technology Promises Converged Wireless Devices

New, low-power signal-processing technology being developed for the Navy may lead to multifunction wireless devices capable of communicating over a wide number of frequencies and protocols.

In August, Kenet, a Woburn, Mass.-based fabless semiconductor company spun out of MIT, received a $1.3 million dollar subcontract to develop an advanced 12-bit analog-to-digital signal converter, or ADC, as part of defense contractor BAE Systems' work on software-defined radio for the U.S. Office of Naval Research.

A software-defined radio can send and receive any radio frequency protocol. Unlike, say, an AM radio, its hardware does not limit the kind of signals it can understand. The U.S. military is currently developing the technology to make its battlefield communications more flexible and interoperable.

Mike Ziehl, VP of marketing at Kenet, says that the ADC his company is developing will require 300 milliwatts, significantly less than a recently introduced competing chip that draws 2.3 watts. "It literally enables this whole idea of software-defined radio by enlarging the bandwidth, increasing the resolution, reducing the power -- really making it something that's realizable rather than something that, up until now, was just a military, homeland security-type product, because it's pretty power hungry," he says.

Kenet was founded in 2002, based on the license of seven patents. The company has filed 15 patents since then, with more planned.

The software-defined radio, or SDR, that BAE is developing "will have hundreds if not thousands of radio channels, each one of which needs an ADC," says Ziehl. "Think of 2 watts of savings times 500 channels. It adds up to a lot of power."

Matt Ettus, who runs Ettus Research, a digital signal processor, software radio, and wireless system design consulting firm, says the technology is impressive but not unprecedented. He points to the as-yet-unavailable AD9230 from Analog Devices as a comparable component.

ADCs are a critical component for any digital device because, as Ziehl puts it, "we live in an analog world." Digital music files, for instance, don't mean much until translated into sound with the help of an ADC. Thus, Kenet's technology will have applications in a variety of professional and consumer electronics.

"The impact on the radio area is pretty impressive," says Ziehl. As an example, he says that combining an XM radio with an Apple iPod nano would reduce battery life dramatically. "I've love to have XM radio in my nano, but I don't want it if I could only listen to it for an hour," he says. "But our technology would enable that kind of converged device with no decrease in battery life."

It may be a few years before the technology makes it to the consumer market, says Ziehl, "but it's coming."

On that point at least, Ettus concurs. "The impacts of SDR will trickle down to consumer products over the next five years," he says.