ECE Ingenuity News
Vol. 7, No. 1
March 2002

by
Diana Meyer

More than 50 years ago, Yuen Tze Lo (MSEE'49, PhD'52) first set foot on the U of I campus after leaving war-ravaged China aboard a World War II troop transport ship. Passing through Urbana on his way to Ohio State, he stopped to visit a friend who casually invited him to stay. Within minutes after entering the admissions office, he was accepted into the electrical engineering graduate program.

The Communist revolution prevented Lo's return to China after completion of his master's degree. Fortunately, he earned a foreign student fellowship award that sustained him financially through the lean years of graduate school when he lost all contact with his family.

As he completed his doctorate in 1952, Lo faced a depressed economy. Few employers were interested in his defense-related research in the antenna field. Hearing about a small start-up company near Poughkeepsie, NY, with immediate openings for engineers, Lo used the last of his money to purchase a train ticket to interview with Channel Master Corp. When asked when he could start, he said: "Today! I have no money to return to Illinois."

Four years later, in 1956, Lo bumped into Ed Jordan, his former PhD adviser, at an IEEE meeting in New York City. When asked how he was doing, Lo confided, "The company treats me very well, but this job is not for me. Any engineer with a bachelor degree could do what I'm doing."

Jordan, who had become head of U of I's Department of Electrical Engineering, immediately extended an invitation to Lo to join the faculty and conduct research in the Antenna Lab. Lo accepted at once, staying until his retirement in 1990.

The Antenna Lab had experienced tremendous growth in the early 1950s, due largely to America's involvement in the Korean War and escalating Cold War tensions. Lo's contributions during the 1950s and 1960s helped to form the foundation for what is now the Electromagnetics Lab.

In 1958-59, Lo introduced the theory of moments during a course he taught in mathematical techniques for electromagnetics. The theory failed to gain much attention due to the limited number of computer facilities at that time. However, a few years later, his theory became highly successful and widely used. His four-volume Antenna Handbook series, written in collaboration with Professor S.W. Lee, covers everything from mathematical techniques to antenna theory and applications. The textbooks have been used by thousands of educators and students around the world.

Lo's research accomplishments include the invention of the broadband television receiving antenna, still mounted on rooftops throughout the world. The feed system for the U of I radio telescope was designed by Lo, incorporating many conical log-spirals. He and his graduate students solved the problem of maximizing signal-to-noise ratio in receiving antennas and were among the first to formulate a complete theory for devices producing perfect, circularly polarized waves. Lo's antenna designs have improved the efficiency of giant radio telescopes, military and civilian radars, airborne and space vehicles, and ground-based communication systems.

As a faculty member, Lo led several studies of problems associated with spherical reflector antennas. This discrete reflector (above), which was built by Ernest Sammann (BSEE '72, MSEE '77), was designed to overcome problems with aberrations. It was constructed using many dipole elements terminated with shorted stubs of various lengths, and was used to track enemy aircraft.

After developing a cavity model theory for microstrip patch antennas, now used in global positioning systems, Lo served two terms as an IEEE Distinguished Lecturer on this subject. He often wore a microstrip antenna that a colleague had fashioned into a tie tac for him. Lo served as director of the Electromagnetics Lab from 1982 to 1990. In 1986, he was elected to the National Academy of Engineering, the highest professional distinction in engineering, for inventions and innovative ideas that significantly advanced the theory and design of antennas and arrays. In 1996, Lo received IEEE's Antenna Propagation Society Distinguished Achievement Award for lifetime contributions.

Lo and his wife Sara de Mundo often welcomed students in their home and to at least one student, he became affectionately known as a "surrogate mother." Lo is humble about his professional accomplishments and takes more pride in the achievements of his students. He claims that many of his students are much more famous than he, including two former students, Professor Shung-Wu Lee and Dr. John H. Bruning, also elected to the National Academy of Engineering.

"Many great inventions are products of hard work and lots of luck," said Lo. "Often it's a mistake that equates to a positive product. More than remembering formulas, asking 'why' is the most important thing. New applications and products are always being developed, but theories and ideas are the basis."