Roy Choudhury, Hanumolu, and Gong join ECE ILLINOIS

The first weeks of the fall semester abound with new beginnings. Freshmen can be spotted studying campus maps, locating classrooms and club meetings. Teaching assistants meet their discussion groups for the first time. Academic organizations recruit new students. And this year, the ECE Department welcomes three new faculty members, each bringing novel teaching and research expertise: Associate Professors Romit Roy Choudhury and Pavan Kumar Hanumolu and Assistant Professor Songbin Gong.

For Roy Choudhury, at least, the campus is nothing new. He received his graduate degrees from the Illinois in 2006. His master’s was in electrical engineering, and although his PhD was in computer science, his doctoral advisor was Professor Nitin H Vaidya from this department. Since then, he has been a faculty member at Duke University, where his research team has focused on wireless networking and mobile computing. He became a tenured associate professor there in 2011. 

“Illinois is a place which has both breadth and the depth. That was really appealing, to be able to knock on anyone else’s door, and say, ‘I’m thinking of this problem, and this has a component that seems to be up your alley. Why don’t we come together and do something?’” he said. He will be based at the Coordinated Science Laboratory, which was established with the specific intent of facilitating these cross-disciplinary projects, and he will hold an affiliated faculty position with the Department of Computer Science. 

Roy Choudhury describes the two broad categories of his research in terms of bottom-up or top-down construction. “The lower-layer hardware, communication techniques, and signal processing—they are like Lego blocks,” he said. In a world where new Lego blocks are being created, his wireless networking research focuses on combining new and existing blocks to create novel communication structures. “I like to build wireless networks that I can demonstrate,” he said. One example might be a Wi-Fi network for a campus bus service.

His mobile computing research works in reverse fashion. They envision the kinds of mobile applications that they would like to see in the next ten to twenty years, and then they ask whether the necessary Lego blocks have been constructed. If not, they begin developing those components internally or through collaboration. 

His recent work includes a project, funded by a Google Faculty Research Award, to design a Google Glass application that would recognize humans (and perhaps whisper names into your ear) without employing face recognition. He is also interested in developing various forms of localization technology, including indoor localization, energy-efficient localization, object localization, and human localization. Additional research includes smartphone sensing, activity and gesture recognition, and psychological computing.

Roy Choudhury is quick to point to the large number of undergraduates who worked in his lab at Duke. “My undergraduates have published first-author papers at top conferences,” he said. Many have gone on to top-five graduate programs, and others have established startups. “I have research projects for passionate undergraduates from ECE and CS, and I look forward to working with them.” 

Like Roy Choudhury, Hanumolu is based in the Coordinated Science Laboratory. He comes to the department from Oregon State University, where he has been a faculty member since 2006, most recently as a tenured associate professor. He has been at Illinois since June of this year, and he is already an established member of the System On Nanoscale FabroCs (SONIC) Center, a multi-university research group based at Illinois.

Hanumolu’s research focuses on mixed-signal circuits—the type of circuits in which analog and digital components are combined on a single chip. “These are sort of the interface between the real world and boxes (or computers),” he said. In previous decades this work was less collaborative. “You could just sort of sit in your cube, design your magic circuit, and then you could be famous,” he said. But because this is now a very mature area of research, the emphasis is less on designing individual analog or digital elements, but rather on making the whole system work. The SONIC Center, in that way, is a perfect fit for his expertise, as it endeavors to bring together researchers of diverse specialties, to create highly functional systems. 

He is particularly interested in resolving power constraints in the circuits. “People know already how to make computers faster. They won’t make it faster because they are constrained by power,” he said. This involves research on clocking circuits for high-speed, low-power I/O interfaces, time-based signal processing, and power management circuits. He is also interested in using digital techniques to compensate for analog circuit imperfections.

“You have the guys who wrote the books—the textbooks. So there is a list of many, many people to look up to here,” Hanumolu said of his fellow faculty members. Yet, in terms of circuit design, “I think I will fill in the gap, in the sense that there are a lot of people doing computer architecture, system-level research, so and so-forth, but not analog circuits, which are essential in all of these digital communication systems.” 

Hanumolu is also excited to work with undergraduate students in the department; it’s one of the reasons he wanted to come here. “For me, the ultimate validation that I am doing my job properly is to see these guys go out and make new things or become millionaires, either would work,” he said. At the Oregon State University, students chose him for the Professor of the Year Award in 2008, based on his ability to inspire and engage. 

In addition, both Hanumolu and Roy Choudhury were awarded the CAREER Award by the National Science Foundation, in 2010 and 2007, respectively. Those are given to junior faculty members who show innovative research and exceptional teaching and leadership.

Gong, the youngest of the three, comes to the department from a research position at Carnegie Mellon University. He completed his graduate work at the University of Virginia in 2010, and he is now based in the Micro and Nanotechnology Laboratory, as an expert in the development of chip-scale components for radio frequency communications, particularly microelectromechanical systems (or MEMS).

These components could be used in cellphones and other telecommunication devices. “One of the challenges nowadays for this type of wireless communications is that the system…is equipped with more and more capabilities, and that requires more frequency bands,” he said. Since most smartphones are outfitted with GPS, Bluetooth, Wi-Fi, and more than a dozen other modes of wireless communication, the hardware must become more adaptive. It must utilize the whole spectrum of radio frequencies more intelligently. 

“It’s kind of like, your radio can only speak one language because you use one particular frequency. My goal is to make the radio ‘multilingual’… it will scan the spectrum and identify what language other radios can speak, and then it will speak that language,” Gong said. 

Along these lines, a component that he recently demonstrated—a monolithic wideband radio-frequency filter with laterally vibrating MEMS resonators using lithium niobate, the first of its kind—could provide a new framework for implementing adaptive radio frequency systems. These preliminary filters can operate with high performance at two separate frequencies on a single chip measuring as little as 0.5 mm². “Such small size allows the use of arrays of monolithic filters to cover all the existing radio frequency standards and will enable dynamic in-field adaptation to radio frequency ambiance,” Gong said. 

Gong knew of the reputation of the ECE Department and of long-time professors like John Bardeen, the co-inventor of the transistor, even before entering graduate school, while he was living in China, his home country. “It’s a great department with a long tradition of engineering innovations and history. So that’s one of the reason that I wanted to be a part of this place… to uphold that tradition and bring my own contribution to the department by doing cutting-edge research."

Like the other new faculty members, Gong encourages undergraduates, in addition to graduate students, to consider working on a project in his lab. “I would love to work with undergrad students…I welcome them to join my group and do some work, to discover what their real research interests are and hopefully, if they decide to pursue graduate study, I also welcome them to join my group as well,” he said.

As this fall semester gains speed, the campus maps will soon be discarded. Student clubs will begin preparing for upcoming competitions and events, and these new faculty members—Roy Choudhury, Hanumolu, and Gong—will become established on campus, well known to students in the classroom and the lab alike.