Four professors in UC Santa Barbara’s College of Engineering have been recognized by their peers as the Institute of Electrical and Electronics Engineers (IEEE), the world’s largest technical professional organization, announced its major awards and recognitions for 2022. Umesh Mishra, the Donald W. Whittier Distinguished Professor in the Electrical and Computer Engineering (ECE) Department, received one of the IEEE’s most prestigious honors, the 2022 Jun-ichi Nishizawa Medal. Professors James Buckwalter, Igor Mezić, and Timothy Sherwood were elevated to the rank of Fellow, the highest grade of membership that the institute confers upon its members in acknowledgement of their extraordinary record of accomplishments in one of the IEEE’s fields of interest.
“From ensuring the integrity and efficiency of computer architecture and circuits, to broadening the applications of the Koopman operator theory and gallium nitride in electronics — professors Sherwood, Buckwalter, Mezić, and Mishra are conducting pioneering research that advances technology for the benefit of humanity, which is the IEEE’s ultimate mission,” said Tresa Pollock, Alcoa Distinguished Professor Materials and interim dean of UCSB’s College of Engineering and the Alcoa Distinguished Professor of Materials. “We offer congratulations to each of them for receiving these well-deserved honors from their peers.”
Electrical and computer engineering professor Umesh Mishra recalls a Saturday afternoon in 1994 when his colleague at UCSB, Steven DenBaars, now a distinguished professor in the Departments of Materials and Electrical and Computer Engineering (ECE), asked him to come to his office.
“He showed me an article in a Japanese trade magazine that featured a blue light-emitting diode (LED) with a brightness of 1 candela that was developed by a scientist named Shuji Nakamura in Japan,” he explains. “At that instant, Steve and I knew the world had changed, and we decided to switch our research programs to gallium nitride (GaN), with my emphasis being on electronics.”
Fast forward nearly twenty-eight years; the landscapes at UCSB and the world, for that matter, have changed significantly since that discussion. Mishra’s work remains focused primarily on the development of GaN materials and devices for electronics while contributing to opto-electronics by working on the electronic properties of LEDs and micro-LEDs. Nakamura, now a materials professor at UCSB, received the 2014 Nobel Prize in Physics for the invention of the efficient blue LED, which has enabled bright, energy-saving white light sources. The university is also home to the Solid State Lighting & Energy Electronics Center (SSLEEC), a world-renowned interdisciplinary center where industry partners, student researchers, and faculty collaborate to advance solid-state lighting and energy-efficient power switching using wide-bandgap semiconductors. Under the leadership of Nakamura, DenBaars, Mishra, and materials professor James Speck, SSLEEC has pioneered GaN-based technologies, producing nearly two hundred patents over the past six years.
“Under sustained funding from the Office of Naval Research (ONR) and the Defense Advanced Research Projects Agency, we developed GaN technology for the world’s first microwave power transistors and advanced them to a level that now forms the backbone of the infrastructure of 5G, and eventually 6G and beyond, which speaks to the longevity of our work and GaN,” said Mishra.
ONR and SSLEEC funding also helped develop power conversion transistors with a voltage-handling capacity of more than one thousand volts, which sparked a new industry of highly efficient power supplies for data servers, on-board chargers for electric vehicles, photovoltaic inverters, and miniaturized adapters for cell phones and laptops.
“Enhancing power-conversion efficiency saves more than $40 billion annually or the equivalent of over three hundred coal-fired power plants,” Mishra says. “The beneficial impact of efficient GaN electronics on the climate is significant. I am hopeful that as GaN electronics become more mainstream, the true benefit to society through the connectivity provided by 5G/6G and the efficiencies in power conversion will continuously grow.”
In recognition of his “contributions to the development of gallium-based electronics,” the IEEE Board of Directors selected Mishra to receive the 2022 Jun-ichi Nishizawa Medal, an honor awarded annually to one individual who is in the fields of materials science and device technologies. Nishizawa, considered to be the father of Japanese microelectronics, contributed important innovations in the fields of optical communications and semiconductor devices.
“I am both humbled and honored to receive the Jun-ichi Nishizawa Medal. He was a pioneer and a major contributor to the development of bright red double-heterostructure LED,” said Mishra, who is also an elected member of the National Academy of Engineering and a fellow of the IEEE and the National Academy of Inventors. “On a personal level, this award gives me a platform to publicly express my thanks. I am indebted to my colleagues at UCSB, past and present, who helped create the world-leading nitride semiconductor activity and eco-system at UCSB.”
Mishra thanked a list of SSLEEC colleagues that included DenBaars, Nakamura, Speck, John Bowers, Ram Seshadri, Stacia Keller, Robert York, Michael Gordon, Chris Van de Walle, Mattanjah S. de Vries, and Claude Weisbuch, among many others. He also expressed gratitude to his students, postdoctoral researchers, and the agencies who have funded his research.
“What the award means to me professionally is that working in a nurturing and collaborative environment with colleagues who want to change the world leads to amazing outcomes, and that it isn’t easy; it takes decades,” said Mishra. “I truly believe this success could happen only at UCSB.”
Computer science professor Timothy Sherwood says that his desire to live in a world where people can really trust all computers to be free from any easy-to-exploit vulnerabilities fuels his research, which lies in the areas of computer architecture. Specifically, he develops novel high-throughput hardware and software methods to monitor and analyze systems. Such techniques offer critical insight on performance anomalies, energy efficiency, and software bugs, while helping to secure critical systems from attacks.
“My collaborators and I have been working on different approaches to this problem with the vision that a more mathematically well-defined form of computation can avoid many of these problems,” said Sherwood. “That perhaps sounds a bit theoretical, but outside-the-box thinking has already led to new ways of building computing machines, with implications for building more secure hardware, for energy-efficient computing with superconducting electronics, and for how we maintain our privacy in an age of hyper-connectedness and beyond.”
Being selected as an IEEE Fellow is considered an extraordinary accomplishment to members and is a distinction that Sherwood is grateful to receive. He was cited by his peers for his “contributions to computer system security and performance analysis.”
“Elevation to IEEE Fellow is a wonderful honor, and I simply could not be more pleased to be recognized,” said Sherwood. “UC Santa Barbara is an amazing place for research, and I am just so appreciative of the collaborative and interdisciplinary spirit of this place. My students and colleagues here are what keep me going and each day with them brings new discoveries and surprises that really add up over the years.”
Previous honors received by Sherwood include the Maurice Wilkes Award for outstanding contributions to computer architecture from the Association for Computing Machinery, numerous best paper awards from top conferences, as well as the Outstanding Graduate Mentor Award and the Distinguished Teaching Award from UCSB’s Academic Senate.
A professor in the Mechanical Engineering Department, Igor Mezić, was honored by the IEEE for his “contributions to modeling and control using Koopman operator techniques.” The Koopman operator theory is a sophisticated mathematical approach of using data-driven analysis of nonlinear flows to understand and forecast dynamical systems.
“This is a wonderful honor,” said Mezić, who is also a fellow of the American Physical Society and the Society of Industrial and Applied Mathematics (SIAM. “I was nominated for my contributions in dynamical system theory. The systems and control area of IEEE is an extremely strong scientific and mathematical community, so I am especially proud that they deemed my work worth of elevation to a Fellow.”
Mezić started applying the mathematical framework in an effort to model complex systems as part of his PhD dissertation, which is when he discovered the first algorithms that enabled the modeling dynamical processes directly from acquired data. Since then, he, his students, and collaborators have continued to develop the algorithms and expand their applications, pioneering use of Koopman operator theory in dynamical systems. The methodology is used today in numerous areas that include fluid mechanics, network security, energy efficiency in buildings, artificial intelligence, power-grid dynamics, and COVID-19 epidemiology.
“All of those fields can have a tremendous impact on improving the human condition” said Mezić, who is also director of UCSB’s Center for Energy Efficient Design and head of the Buildings and Design Solutions Group at the COE’s Institute for Energy Efficiency. “Ultimately, the realization of that improvement using our work would be the biggest prize.”
5G networks, the new generation of wireless communications, is being powered by a specific part of the electromagnetic spectrum known as millimeter wave (mmWave). The high-frequency bands have short wavelengths, varying in length from 10 millimeters (30 GHz) to 1 mm (300 GHz), that facilitate the increased capacity and speed of wireless networks. The mmWave has broad applications ranging from autonomous vehicles and drone communication to radar and Internet of Things (IoT) devices.
However, because of its high frequencies, the mmWave has limitations. The waves are easily absorbed by atmospheric gasses and rain, and they only move in line-of-sight paths, meaning buildings and trees can impede them. While those characteristics pose challenges for full-scale deployment of mmWave technologies, researchers like James Buckwalter, an electrical and computer engineering professor at UCSB, have been investigating novel approaches to help deliver on the promise of mmWave.
“I’m trying to understand the fundamental limits of energy efficiency that govern high-frequency electronic devices and systems,” explained Buckwalter. “While the conventional complementary metal-oxide semiconductor (CMOS) circuit chips, found in microprocessors and cell phones, face substantial limits in terms of efficiency when they operate at high frequencies, my research recognized that silicon-on-insulator (SOI) CMOS allows new circuit concepts that significantly improve the power and efficiency in millimeter-wave bands.”
Among the new devices facilitated by SOI CMOS are power amplifiers, which are small circuits that convert a low-power radio frequency (RF) signal into a higher power signal that can reach the required transmission distance.
“We are now standing at the threshold of a new era where photonic devices and mmWave circuits converge on a single SOI chip that leverages substantial integration of digital signal processing and goes beyond the system predicted by Moore’s law scaling,” said Buckwalter, referring to the principle, named after a co-founder of Intel, that states that the number of transistors on a microchip doubles about every two years, though the cost of computers is halved.
In recognition of his “contributions to high-efficiency millimeter-wave power amplifiers and optical transceivers in silicon-on-insulator (SOI) technologies,” the IEEE Board of Directors elevated Buckwalter’s status to the grade of Fellow.
“The IEEE represents a global research community that is responsible for an astounding fraction of the technological advances that have made our lives and societies stronger, healthier, and more robust; these are the engineers that turn the dreams of science fiction into reality for everyone,” said Buckwalter. “I am extremely proud to be a part of the Microwave Theory and Techniques Society, interacting with the brightest minds, and being elevated to this select group is a profoundly humbling recognition. And as an IEEE Fellow, I feel responsible training and mentoring the scholarly achievement of the next generation of brilliant engineers.”
Buckwalter describes microwave and mmWave circuit technologies as critical to the development of new applications, such as autonomous vehicles, extended reality, and a new era of global satellite networks. He says that discovering ways to improve the energy efficiency of mmWave technologies remains a critical problem, and one that he is committed to solving.
“I hope my technical contributions not only impact our ability to leverage more of the radio spectrum, but also help inform an up-and-coming generation of engineering scholars on the most relevant technical challenges,” said Buckwalter, whose previous honors include an Early CAREER Award from the National Science Foundation and a Defense Advanced Research Projects Agency (DARPA) Young Faculty Award.
About the IEEE
The IEEE includes more than 400,000 members from nearly 160 countries. The total number of fellows selected in a year cannot exceed one-tenth of one-percent of the IEEE’s voting membership. The Class of 2022 Fellows includes nearly three hundred members.