Samir Nooshabadi looks to close the terahertz gap for better communication

Samir Nooshabadi received fellowships from the Department of Defense and the IEEE Microwave Theory and Techniques Society to pursue research in developing a high-data rate communications system based on a high-power terahertz source.

Nooshabadi, who graduated summa cum laude with a BSE in Electrical Engineering this past spring, worked with Prof. Ehsan Afshari in the Ultra high-speed Nonlinar Integrated Circuit lab (UNIC). Nooshabadi helped design tiny transmitters which can operate based on a terahertz source. Although there’s not much power on such small devices, they can network together and function as an array, allowing for greater possibilities.

Nooshabadi is interested in solving fundamental problems in teraherz design so that the technology can be used in a wide variety of applications. Terahertz sources operate at a much higher frequency than other sources, and they are non-ionizing, which means they aren’t harmful to you in the way x-rays are. Using terahertz sources could help improve the safety of imaging systems (X-rays) for cancer screenings and dental exams.

“Certain types of cancer change the water content in your skin,” Nooshabadi said. “You can use terahertz sources to detect the onset of tumors, and the cool thing is that it doesn’t harm you.”

Terahertz sources could also help improve diabetes testing.

“People who are diabetic have to pin prick their skin to check their glucose levels, but with a terahertz source, you could just use a portable device as a breathalyzer,” Nooshabadi said. “Your breath has glucose molecules that the device could sense.”

The problem is terahertz sources are too high for solid-state devices to generate enough power to do all these things. However, terahertz sources are also too low for optical frequencies, and this creates what is known as the “terahertz gap.” Nooshabadi and the UNIC work to solve issues that arise with the terahertz gap in order to implement novel systems on silicon and other low-cost technologies.

“It all requires new circuit techniques and new ideas to overcome the roadblocks,” Nooshabadi said.

Nooshabadi became interested in wireless systems as a freshman as part of a Multidisciplinary Design Project when he helped design a wireless sensor node network for modeling microclimates. The sensor nodes were shaped like maple seeds and would float in the wind, recording data for wind vector analysis.

Nooshabadi said he is most grateful to U-M for the opportunity to work on these kinds of projects.

“There are lot of very famous, very respected faculty here that do a lot of interesting research,” Nooshabadi said. “As an undergraduate, it’s a really good opportunity to get to interact with them and do all this cool research.”

Nooshabadi, originally from the U.P., will be heading West this fall to begin a PhD at CalTech. He is currently interning at SRI, an independent, nonprofit research center.