Presentation of the 2002 Phil Kaufman Award to Ron Rohrer
It is a special pleasure and an honor for me once again to present the ninth annual Phil Kaufman Award to Dr. Ronald A. Rohrer.
Usually when I describe the contributions of a Kaufmann winner, I sit down and try to construct an orderly timeline of their career and accomplishments. But much in line with Ron’s early work as a circuit theorist, his career has had a highly nonlinear trajectory—better thought of perhaps as a collage, or an abstract, and certainly not as any product of the schools of realism or still-life. There is no single line of thought that I can find that can truly capture the many important contributions Ron has made. The words that continually surfaced in all of my conversations with people about Ron included: passion, focus, enthusiasm, inspiration, creative, innovative, not to mention educator, mentor, radical, and friend.
As Ron’s spouse and partner Casey Jones told me, “Ron has amazing technical vision—he has the ability to somehow see all the threads. But at the same time Ron doesn’t get ‘stuck’ on an idea, trying to prove that it is true. He really enjoys evolving and refining ideas, especially with other people. He is focused on finding a solution, not just on being ‘right.’” That has certainly been my own experience with Ron as well. I remember a brief discussion we had prior to his development of what was later to become one of his major technical contributions—Asymptotic Waveform Evaluation, or AWE—where he was trying to explain to me what he was looking for and I must say I left the conversation pretty confused. It was 1989 when Ron finally introduced us to AWE, a technology that formed the basis of an industry wide interconnection reduction approach for efficient delay calculation for integrated circuits.
When I heard my first talk about AWE, it was immediately very clear and correlated with what Ron had been trying to explain to me earlier. When I recounted this experience to Casey, and confessed that I felt a bit stupid for not ‘getting it’ when Ron first tried to explain it to me, she kindly explained that, “Well, even Ron probably didn’t totally understand where he was going with the ideas back then. He was evolving the idea himself.” Thank you, Casey.
Tom Beckley, President and CEO of Neolinear also recounted that “Ron often gets to a good solution so quickly that for many of us, the light bulb doesn’t fully click on until days later.” But that is how these major new ideas evolve for Ron, whether it is in technology or in business—most likely in life as well!
Ron developed the AWE work while a member of the faculty at Carnegie-Mellon University (CMU). Larry Pileggi, now himself a distinguished faculty member at CMU and Ron’s Ph.D. student from 1986-89, recalls that during that time Casey was living and working back east for a while and Ron was commuting. He would work at CMU during the week, travel to spend time with Casey on the weekends and return to Pittsburgh for a Monday morning start. “Ron’s students always wanted to set their weekly research appointment with him for the Monday,” says Larry. “He was always in a great mood when he came back on Mondays. He was at his crankiest on a Friday—that was the worst time to discuss research with Ron. But in terms of working with Ron as a PhD student at CMU—this remains the highlight of my career.”
Although Ron says he hated school from his very first grade on—and somehow I can appreciate that; I just wonder how his school teachers felt about him as well—he built his career on a very solid foundation, with early degrees at both MIT and Berkeley. “Ron was one of the smartest students I have had the pleasure to advise, and always had very good ideas,” said Ernie Kuh, Ron’s Ph.D. advisor at Berkeley and a fellow Kaufman Award winner. “His Ph. D. involved fundamental and elegant work on certain theoretical aspects of time-varying circuits.” When I asked Ron about his Ph. D. he responded that “it was so theoretical, it is best forgotten!” But during that time he met a man who had a profound effect on his life and who he credits with teaching him his own approach to mentoring students in the years to follow—Professor Mac Van Valkenburg of the University of Illinois, Urbana-Champaign, described by many as one of the very best engineering educators of our time. Ernie was on sabbatical when Mac came to spend an extended period at Berkeley and took over the day-to-day advising of Ernie’s research group. “Mac understood that ideas needed to be nourished, no matter how wacky they seemed at first. He liked everything I presented to him!” Ron told me.
No wonder that upon graduation Ron went to work with Mac at Illinois, where he began his own career as a mentor. One of his first Ph. D. students at Illinois was our own Berkeley Professor Leon Chua, for example.
Even in those days, Ron’s influence had an international impact “I was first ‘introduced’ to Ron Rohrer in 1968 as an undergraduate student in Italy when I was considering a career in circuit theory.” Kaufman Award winner Professor Alberto Sangiovanni-Vincentelli told me. “Ron’s paper on Fully Automated Network Design was the main motivation for me to look into computer-aided design as a promising area for research—one with interesting mathematical foundations.”
“I always saw Ron as a ‘Rebel with a Cause’,” says Professor Bob Meyer at Berkeley, one of Ron’s earliest faculty colleagues. “A rebel—both technically and socially in those days—and always passionate about what he was doing—always with a cause. Just an amazing guy!” Bob Meyer remembers when Ron gave a seminar after returning from a stint working with industry at Fairchild. His talk was titled “What I learned about design this summer.” Now don’t forget—Ron began his career as a quintessential theorist. He drew a very complex I/V characteristic on the board and said, “I used to be a circuit theorist concerned with resistors like this,” Then he drew the simple exponential I/V characteristic of a semiconductor diode on the board and said, “Now, the only resistor I am interested in looks like this.” Find the essential understanding of the problem—simplify it to its core elements—and focus your thinking, all your energy, right there.
As Ron told me recently, “Complexity is the real enemy. If you start out with a complex solution, you get ‘complexity cubed.’ The key is to find the essential simplification—the core idea.” This is a theme that many have observed in Ron’s approach to problem solving.
According to Ernie Kuh, Ron was always a very innovative teacher. “When I became EECS department chair at Berkeley , I handed over responsibility for [advanced circuit theory courses] EE222 and EE223 to Ron. I gave him my teaching materials, the syllabus, and so on. But Ron threw all that out and ran EE223 as a project course! I think it was the first time we had a project course like that at Berkeley —and of course that project course sequence led to the program CANCER and eventually to SPICE.” SPICE author Dr. Larry Nagel told me that, “Ron consistently tried and succeeded bringing new methods into the classroom.”
Dr. Dick Dowell, another of Ron’s Ph. D. students and a one of Ron’s student ‘Rat Pack’ as they referred to themselves back then, met Ron through EE222. Dick had heard from a fellow student that EE222 from Professor Rohrer was the hardest course he had taken in his life and that this guy was the toughest son of a gun he had ever met. Dick thought this sounded like a great challenge and so he enrolled to see what this guy was really like, “expecting a 55 year old Professor with gray hair,” recalls Dick. “But instead, in walks this kid! He started talking to the class and was even funny! He announced that the class this semester would involve writing computer programs and commented: ‘By the way, if you don’t know how to program, neither do I, so just go to the student store and buy a book on it.’”
The next semester Ron continued his exploration. Larry Nagel recalls: “I had enrolled expecting a circuit theory course—actually, at the time I had very little interest in circuit simulation, as I considered myself a circuit designer.” Ron announced that the rules for this class were that there would be no exams, “If you write a program Don Pederson likes, you get a passing grade. If he doesn’t like it, you don’t pass the course. That’s it.”
Dick Dowell was also a member of the team that developed CANCER and recalls that, “To this day, with more than thirty years of industrial and research experience under my belt, I have never seen a better job of project management than the way Ron managed that class—that group of students.”
Larry Nagel summarizes that experience by saying, “If Don Pederson is the ‘Father of SPICE’ then Ron is its Godfather. It never would have happened without him. Ron represented the intellect behind SPICE, while Don was really its soul. Both roles were critical to its eventual success.
Ron had a definite hand in just about everything in CAD in those days. It was back in 1965, when Ron was teaching and working with Don Youla at Brooklyn Polytechnic Institute that he developed the basis for what we now refer to as the Adjoint Sensitivity Method. Published in 1969, the adjoint sensitivity method in circuit simulation lead to Ron’s invention of what we now call noise analysis and its extension to distortion analysis as well. Many people don’t realize it, but a large fraction of the algorithms and techniques in widespread use today for the analysis of very high frequency circuits—what we often refer to as ‘microwave analysis’—are also directly due to Ron and this important early work.
I think fellow Kaufman Award winner Don Pederson summed it up well when he told me, “Ron can take the technological problem at hand, understand it quickly, he can identify the key theoretical simplification needed and then can generalize to the appropriate technological solution. But Ron can move so fast that only a few people can really understand and keep up with him as he goes through it.”
Ron has continued his innovation in both research and teaching—heck, in everything he does—wherever he has been since. At CMU he built what one student referred to as a ‘circuit simulator for dummies’ to introduce basic concepts in circuit design and analysis to first year undergraduates. “With its graphical user interface, if a transistor was dissipating too much power it would turn red.”
Michigan Dean Stephen Director had had the proverbial “360 degree” exposure to Ron throughout his career, first as one of Ron’s Ph. D. students, then as a colleague, and finally as Ron’s department chair at CMU—I hesitate to call him Ron’s ‘boss.’ Steve says, “One of the characteristics that I appreciate the most, and probably has personally influenced me the greatest, has been Ron’s demonstration that you can simultaneously be an outstanding researcher and an outstanding educator; that the creation of new knowledge and its dissemination in a clear and concise way go hand in hand. Ron is an outstanding teacher, advisor and mentor to me and to all his students.”
“Ron is one of the greatest teachers I know!,” continues Dr. Aart De Geus, founder, Chairman and CEO of Synopsys and also one of Ron’s Ph. D. students. “He is not one of those professors that expects you to become like them. Rather, he is a teacher who gives you the support and the courage to find your own talents and one who brings out the best in you. Just as much as Ron cannot stand ‘No, because…’ people; he is the prototypical ‘Yes, if…’ thinker himself. A new idea is always welcome; a new perspective always deserves exploration. It is that attitude that has made him into a great researcher but even more into a great educator and mentor.” Aart continued, “Today at Synopsys we teach every manager that their job is first and foremost to make every member of their team ‘an inch taller’. I learned this important lesson from Ron and it is fair to say that I owe at least a yard of my height to him. I will always be grateful for that tremendous gift.”
Another member of Ron’s distinguished group of Ph. D. students, Dr. Aykut Dengi of Neolinear summed it up this way: “For Ron, everything starts with a ‘wild-assed thought’ and he has a lot of them. Some of them can seem completely ridiculous at first sight. However, nurturing an original idea at these ‘baby stages’—focusing on their strengths and not their weaknesses—is one of Ron’s real strengths.” A theme is developing—the lesson Ron himself learned from Mac Van Valkenburg!
No wonder that Ron was awarded the very prestigious IEEE Education Medal in 1993—one of a number of major awards Ron has received in his distinguished career.
However, as another former student continued, “Ron can also be brutally objective once an idea is past the infancy stage. In fact, his cool-headed, objective criticism is a key to his credibility and the respect people have for him, even with people who don’t like what he has to tell them. Ron’s technical judgment is never marred by personal factors, positive or negative. On the other hand Ron’s blunt honesty has been known to annoy and even embarrass some people who do not know him well.”
In the first half of the 1980’s, Ron also had an active stint in industry as General Manager of Scientific Calculations MicroElectronics Division, as EDA Director of Marketing at Calma Corporation and as EDA Program Manager for the GE Technical Systems Sector.
According to Ron, “The world is divided between ideas people and implementation people.” He told me that “I consider myself and ideas person, and I used to have a lot less respect for the implementation side of things than I do today. I have really learned you need both, and that they’re equally important. Over the years, I have developed a profound respect for the great ‘implementation’ people I have had the luck to work with.” Ron’s experience with business has also taught him a number of important lessons. “Tenacity trumps intellect every time,” he told me. “I have had the luck to work with some truly great entrepreneurs and I often find myself in awe of the sheer pain and suffering they endure as they create their success.”
As Roy Jewell, President and COO of Magma, says, “I’ve been very fortunate to work with Ron for several years now and for a number of different companies. What I’ve found striking about Ron is his ability to grasp the complexity of a situation, see how technology and business issues are tied together, and suggest a course of action that meets the needs of both. Ron has shown an ability to bring his unique brand of creativity to business as well as R&D, which is all too rare.” And, might I add, the quintessential qualities we seek with this Kaufman award.
But so far I haven’t said hardly anything particularly specific about the tremendous technical achievements Ron has brought to our field and to our industry! The adjoint sensitivity method and its application to circuit analysis, automated network design (a quarter century too early Ron, but almost here now—we won’t hold that against you!), the architect and the Godfather of SPICE, the AWE family of techniques and tools that have spawned entire workshops and conferences in their wake, and his insights in so many other areas that have shaped our field—as a theoretician, an engineer, and a true architect. Of course that work is all very important, and you can read about all of it in the press releases. The picture that emerged in my conversations with so many people—many of you here tonight—about Ron and his impact was much more about the man himself and the impact he has had on our lives, about the inspiration and understanding his own passion and determination have brought to so many of us, as his students and as his colleagues in academia and in business.
I remember many years ago now when Professor Don Pederson was writing a letter of reference for Ron and he said to me out of the blue, “You know, I just counted seventeen different jobs Ron has had since he left Berkeley !” And of those, I just counted ten different stints at Universities. In those days, that was far more unusual than it is today! But all of that ‘conventional wisdom’ about what one should or should not do seems so entirely irrelevant in Ron’s case—almost counterproductive. Looking back, it is actually as a direct consequence of his rejection of the norms, seeking his own way and his passion in its pursuit, and then encouraging that very same spirit in every person who has had the opportunity to work with him, that we sit here tonight honoring this man.
One of the ‘radicals’ of our field, one of the giants of our industry and its history, we thank you Ron for all you have done. We certainly would not be where we are today without you and all that you have contributed, in so many ways. When I asked Ron what he attributed most to his success he responded that he felt he had been “lucky enough to be standing around when the right people showed up, and at the right times.” Ron, we are the lucky ones!