Researchers at Lucent Technologies‘ (NYSE: LU) Bell Labs say they have created the first all-silicon chips to receive radio signals from mobile handsets. The development from the company’s R&D arm could potentially slash the cost of creating a radio receiver for wireless networks, as well as shrink the size of traditional gallium arsenide-based radios.
Ironically, the new chip design, introduced today at the International Solid-State Circuits Conference in San Francisco, came one day after Lucent announced it was laying off 18 researchers at the San Francisco office of Bell Labs, ostensibly ending the New Jersey-based company’s yearlong effort to carve out a Silicon Valley presence. But Steve Eisenberg, spokesperson for Lucent, says the cuts won’t hinder Lucent’s R&D.
“The chip development was not done in Silicon Valley, it was done here in New Jersey,” says Eisenberg. “Bell has offices in 30 countries with over 30,000 employees. The Silicon Valley presence was just a part of that effort.
“We expect to use these chips in our next generation of base stations,” he adds.
Gallium arsenide (GaAs) is a semiconductor compound used in some diodes, field-effect transistors, and integrated circuits. GaAs components have proven very useful at ultra-high radio frequencies and in fast electronic switching applications because they generate less noise (unwanted electrical or electromagnetic energy) than most other types of semiconductor components. Unfortunately, it is also a substantially more costly semiconducting material than silicon, but engineers have chosen to use it to satisfy the high-performance requirements of a wireless network. A radio receiver, for example, must handle many weak signals simultaneously, then amplify and filter them before further signal processing occurs, something pure silicon chips could do in the past but with far less efficiency. Bell Labs researchers say they’ve solved that problem, though no word yet on exactly how.
“Only recently have circuit designers made silicon chips for radios that rival the performance of gallium arsenide,” says Bell Labs researcher Jenshan Lin. “Our silicon-based radio receiver is the first of its kind.”
Lin and his colleagues, Olga Boric-Lubecke and Penny Gould, created a radio receiver comprised of only three silicon chips, roughly the size of a quarter, which is 100 times smaller than a gallium arsenide-based radio. Lubecke says the silicon chips are also 10 to 100 times less expensive to manufacture.
“Because base stations with a silicon-based receiver would be smaller, service providers would have greater flexibility when installing them,” claims Lubecke. “For instance, the base stations could be placed in less obtrusive locations, such as behind billboards or on top of utility poles. This might help speed the deployment of the mobile Internet as it continues to grow.”
Gould adds that the all-silicon fabrication approach could also lead to the combination of a base-station radio receiver and digital signal processor on a single chip.
“This would further reduce the base-station cost and move closer to creating a system-on-a-chip solution for base-station radio receivers,” she says.
Research firm Dataquest estimates the market for chips that process radio frequency signals will reach $7 billion by 2002, with the number of wireless devices expected to exceed 450 million.