Fall 2007

COVER STORY The Indispensable Technology The Business of Analog The Full-Circuit Classroom Understanding Analog Analog Technology – In Brief

SINCE IT WAS CHARTERED in 1885, Georgia Tech has stressed economic development and industry collaboration alongside technological education. Nowhere are industry ties stronger than in the field of analog electronics.

photo by Gary Meek Professor Abhijit Chatterjee, left, and graduate student Rajarajan Senguttuvan review images showing receiver adaptation to changing wireless channel conditions, as part of research aimed at minimizing power consumption. (300-dpi JPEG version - 980KB)

To promote closer contacts with the analog-chip industry, in 1989 three Georgia Tech faculty started the Georgia Tech Analog Consortium (GTAC). Today, GTAC is part of the Georgia Electronic Design Center (GEDC), a 250-person center at Georgia Tech that works with nearly 50 industry and government members on analog and mixed-signal technologies for both wireless and wired applications.

“We have very tight synergies with the major players in the field such as Texas Instruments, National Semiconductor, IBM, BAE Systems, Lockheed Martin and others,” says John Cressler, Ken Byers Professor in the School of Electrical and Computer Engineering (ECE) and a GEDC faculty researcher. “That gives us not only access to state-of-the-art technology, but we’re also able to interface with industry very directly.”

And it’s a two-way street, with both industry and Tech deriving important benefits.

“Industry has an obviously high opinion of the analog engineers coming out of Georgia Tech,” says Hal Calhoun, managing director with Menlo Ventures, a large venture-capital firm in California’s Silicon Valley. “You don’t have to travel far to learn that industry is filled with Tech analog engineers, many in important management positions.”

Dennis Monticelli, chief technologist at analog-industry giant National Semiconductor Corp., reflects that industry interest. “Georgia Tech is a school that’s maintained its excellence in analog education,” he says. Working with GEDC and Tech’s ECE school, National is “able to choose the professors we would like to work with, and we get to work with some top students, both graduates and undergraduates.”

How to Succeed in Business
Besides collaboration with established companies, Georgia Tech’s applications-oriented viewpoint has led to numerous startup companies based on the analog/mixed-signal research of GEDC/GTAC, the School of Electrical and Computer Engineering and other Georgia Tech groups.

GEDC identifies 11 companies, in varying stages of development, as having emerged from its research. All told, they have raised some $100 million in venture-capital funding.

The list includes two established companies with roots in the work of GEDC Director Joy Laskar – RF Solutions, a wireless-LAN company now part of Anadigics, Inc., and Quellan, a collaborative signal-processing company.

Several other analog-heavy companies are now members of the Advanced Technology Development Center (ATDC) or VentureLab – Georgia Tech units that help fledgling companies get going by locating startup money, offering business guidance and leasing office space.

These companies include:

• GTronix, an ATDC member that develops analog-integrated circuits (ICs) for ultra-low power portable consumer electronics, is based on the research of Paul Hasler, an ECE associate professor and GTAC team leader.

• Qualtré, an ATDC company that is developing low-cost, all-axis motion sensors for consumer electronics, is based on the work of Farrokh Ayazi, an ECE associate professor and GEDC team leader.

• Axion Biosystems, a VentureLab company developing products that involve analog neural-interfacing technology, is based on the work of the labs of Steve DeWeerth, a professor in the Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, and Mark Allen, senior vice provost for research and innovation at Georgia Tech and Joseph M. Pettit Professor in ECE.

He points to an industry publication listing a number of young analog engineers – including several recent Georgia Tech Ph.D.s – who are now working for top technology corporations. All of them are being sent by their employers to study in top M.B.A. programs.

“These are people who are being groomed to play important management roles in their companies,” Laskar says. “As analog engineers, they’re so valuable that they’re worth the extra training.”

Moreover, Laskar says, young analog graduates frequently do well in startup companies as well. He cites the Korean company Future Communications IC, Inc., a designer of chips for mobile television and wireless communications that was acquired recently by Silicon Motion Technology Corp. for $90 million. Two Georgia Tech analog Ph.D.s, Sangwoo Han and Seungyup Yoo, played major roles in Future Communications’ success.

“Analog training can provide a valuable entrée into industry, business and academia,” Laskar says.

Better Testing, Better Chips
Georgia Tech researchers frequently work on problems that affect how industry produces its microelectronic products – issues with direct consequences for the corporate bottom line.

Analog circuits, especially very-high-frequency, small-scale designs, are susceptible to manufacturing flaws. ECE professors Linda Milor and Abhijit Chatterjee work closely with analog chip makers such as National Semiconductor and Texas Instruments to improve circuit testing during manufacture.

“Manufacturing yields of useable chips is very important,” Chatterjee says. “A small percentage of change in yield – even 1 percent is a big number – can mean the loss of millions of dollars.”

Examining freshly minted circuits can be very expensive, and most analog circuits receive only a cursory automated test during manufacture, says Milor. To enhance robustness and yield, new design approaches with added circuitry could allow chips to examine themselves.

Among other things, Milor has been working on testing of chips’ input and output signals.

“That’s become a problem because of today’s high-speed interfaces between chips,” she explains. “Once the delays have gotten down to tens of picoseconds … generating these very precise timing intervals is hard to do off-chip with external testing equipment.”

One approach to more reliable and capable chips, Chatterjee explains, involves “adaptive electronics” – circuits that not only test themselves but can also self-recalibrate. Chatterjee and his team are currently researching adaptive electronics technology with support from the Gigascale Systems Research Center (GSRC), a multi-university collaboration sponsored by MARCO, a unit of the Semiconductor Research Corp., and by the Defense Advanced Research Projects Agency (DARPA).

“If there’s a problem in the manufacturing, the circuit can reconfigure itself to compensate for these variations,” he says. “In a sense, the chip becomes self-healing.”

Adaptive electronics could also allow a circuit to adjust to changes in its surroundings, Chatterjee says. For example, cell phones could cut back on circuit performance in a strong signal environment more efficiently than they do now, thereby conserving power.

“Current RF front-end design is relatively static, and most components consume about the same power irrespective of the quality of the signal,” Chatterjee says. “Our design dynamically adapts supply voltages and circuits performance to channel conditions, so that the system consumes less power when signal strength is good and then can increase power for a weak signal.”