ECE team takes third place in IC Design contest

A team from CMU’s ECE department, composed of graduate students Abhishek Jajoo, John Reinke, and Leon Wang, recently won third place in the first phase of the 2007–2008 SRC/SIA IC Design Challenge. The team, led by faculty advisers Tamal Mukherjee and Gary Fedder, submitted the award-winning design titled “A Tunable Multiband RF MEMS Transceiver Front-End.”

The theme of the competition this year was “Performing At The Limits,” with the objective of creating novel, high-performance circuit designs that create more competitive end products.
A transceiver is a radio frequency transmitter/receiver, most commonly used in cell phones, WiFi devices, and Bluetooth. Conventional industry transceivers can only operate at individually fixed frequencies — in other words, transceiver circuitry tuned to cell phone frequencies cannot be used to receive WiFi or Bluetooth.

As a result, a cell phone that uses three standards of radio transmission (phone, WiFi, and Bluetooth) would need to have three transceivers tuned separately to each frequency band of transmission and reception.

The winning team’s design, however, aims to change that with its innovative strategy. By utilizing the latest technology in microelectromechanical systems (MEMS), the team’s circuit is capable of receiving and transmitting on several different bands of radio transmission, eliminating the need for multiple transceivers in devices.

“In essence, we’re developing the one circuit that does it all,” Reinke said.

During the first phase of the competition, the eight participating teams designed the circuit and submitted a proposal for evaluation; only the five most promising teams will advance to the second phase, scheduled for later this year.

In the second phase, the five teams’ designs will be fabricated for free, a process which would cost several thousand dollars on its own. Next, judges will test the devices’ circuitry to determine the final winner, who will receive a prize of $25,000. According to a Carnegie Mellon press release, all eight teams will exhibit their posters at TECHCON 2008, a two-track international technology conference.

The Carnegie Mellon team’s design promises better performance than most current versions of transceivers, especially at high frequencies. “This will lower the size and cost, and also the power consumption of electronic devices in the future,” Leon said. In the group’s design, MEMS is used to physically modify the gap between the capacitor plates, allowing for on-the-fly changing of capacitance in the circuit. MEMS is a rapidly growing technology involving use of what are literally “micro-machines,” which can sense and move circuits at the microscopic level.

“In essence, what we’re doing is an integration of mechanical engineering and electrical engineering,” Jajoo said.

Current applications of MEMS include accelerometers in car airbag sensors and the movement sensors in the Wiimote, the main game controller for Nintendo’s Wii console.

The team’s design is a step toward building high-performance circuits of the future, Reinke said. These circuits will not only combine connectivity of cell phones and WiFi; they may also conform to upcoming standards such as those of software-defined radio systems, radio communication in which hardware components such as filters and amplifiers are applied using software.

Submissions for the next stage of the competition are due on May 15, upon which the submitted blueprints will be fabricated by Jazz Semiconductor, a subsidiary of Jazz Technologies, Inc. that designs highly-integrated and power-efficient semiconductor devices.

The fabricated devices will then be returned to the university by mid-September, where judges will physically test their functionalities. A final report on the actual performance of the devices will then be submitted by November, to be judged for Phase 2 of the competition.

“The main challenge is yet to come,” Jajoo said. “Getting things to work in simulation is so much easier than getting them to work on actual silicon.”