The faster Internet connections of the future don’t grow on trees. They grow in the labs of U of M College of Science and Engineering researchers Rhonda Franklin and Bethanie Stadler, both professors of electrical and computer engineering, who work as a team with University of Texas at Dallas associate professor Rashaunda Henderson.
The three have pooled their expertise in electrical engineering to provide circuits able to support today’s 5G networks, as well as tomorrow’s 6G and 7G.
Speed and frequencies in the range of 10s or 100s of gigahertz (GHz) are the essence of such technology. Key to such high-level performance are interconnects— structures that connect circuit elements like transistors and allow signals to flow, preferably without being degraded en route. To meet these standards, the team designs and builds circuits with “nanowire” interconnects so thin that a thousand could bundle inside a human hair.
Franklin’s lab designs and makes the circuits using the materials Stadler’s lab manufactures, and Henderson’s lab tests the circuits’ effectiveness at frequencies up to 325 GHz.
Much of the progress rests on the contributions of students.
“Working with Dr. Franklin was one of the most valuable things I did in undergrad,” says Kate Klungtvedt, a 2020 CSE grad who’s now an Engineering Leadership Program engineer at Dynamics Mission Systems, Bloomington, Minnesota. “I got the chance to work on designing a method to measure the dielectric constant [a measure of a material’s insulating capacity] of biological substances. Dr. Franklin showed me how my work would fit into a much larger project, which made it that much more rewarding.”
The thrill of learning invaluable skills while generating new knowledge emerges as a recurring theme.
“I was part of the team that built and tested the first magnetic nanowires in Prof. Stadler’s group. My focus was to learn how to fabricate and control [their] properties,” recalls Ryan Cobian, who was a graduate electrical engineering student at the time. “We designed and carried out experiments that no book could tell us the answer to. It was exciting to be working on things that had never been done before.” Cobian now helps develop the next generation of magnetic devices as a process development engineer at BH Electronics in Burnsville, Minnesota.
Experiences in Stadler’s lab as undergrads during the last decade also helped launch the careers of Nicolas Schleif, a wireless and communication systems engineer at NASA’s Johnson Space Center in Houston, and Andrew Haldren, a senior professional staff member at Johns Hopkins Applied Physics Laboratory in Maryland.
“My project was to evaluate different methods to measure the length of nanowires once they've been made,” says Schleif. “Working with Professor Stadler was my first experience in working to achieve an ambitious and life-changing idea. The skills I gained in asking good questions, formulating and testing hypotheses, and maintaining curiosity about everything has stayed with me to this day and opened many doors.”
Haldren focused on developing computer simulations of optical circuit components using novel magneto-optic materials and structures.
“I found it very exciting to see how an idea could go from a simple [concept] to discussion, to a more refined simulation of that idea showing how it might work, to a final working physical prototype,” he says. “It was largely this experience that motivated me to continue my education into graduate school and pursue my Ph.D. in electrical engineering.”
- Categories:
- Science and Technology