November 7, 2008
Speaker: Thomas H. Lee, Professor
History might be monotonous, but it's certainly not monotonic, common textbook presentations notwithstanding. The history of radio is no exception to this rule. Soon after the laying of the first transatlantic telegraph cable after the American Civil War, a collection of visionaries and those of dubious mental stability proposed various schemes for wireless communications. In 1872 William Henry Ward and Mahlon Loomis independently patented proposals to use the atmosphere as a conductor. A few years later, David Edward Hughes demonstrated the first portable wireless apparatus before singularly unimpressed members of the Royal Society. The patenting of wireless TDMA by Tufts University professor Amos Dolbear soon after that was greeted with a similar indifference. It took the experiments of Hertz in 1887 to stimulate wider, serious consideration of wireless communications. In short order, Bose, Popov and Lodge demonstrated necessary elements of wireless technology, and fortuitous developments by Calzecchi-Onesti, Ducretet and Branly enabled receivers with adequate sensitivity. Marconi's upscaling of these foundational technologies transformed wireless from a science project into a global business.
This talk will trace those developments, as well as the transition from Marconi's station-to-station spark-based wireless telegraphy to technologies based on the continuous wave, enabling station-to-people broadcasting, and setting the stage for Armstrong's many inventions. We'll meet Braun, de Forest, Fessenden, Alexanderson, as well as less well-known contributors such as Poulsen, Elwell and Fuller. Their contributions — spanning rotating machines, naturally-occurring semiconductors, vacuum tubes, and glowing arcs — highlight the nonlinearity and non-monotonicity of the flow of history.
Tom Lee has been teaching radio frequency (RF) and analog circuit design at Stanford University since 1994. His passion for all things RF was undampened by the prevailing belief at MIT that "RF was a solved problem." His doctoral thesis, believed to describe the first CMOS wireless receiver (an FM radio, in 2um technology), impressed absolutely no one, and likely would have set back the cause of RF CMOS by several years had any journal published his papers. He is the author of several textbooks, including "The Design of CMOS RF Integrated Circuits" (Cambridge Press; 2nd ed.). He's twice won the "Best Paper" award at ISSCC, and was honored with a Packard Foundation Fellowship in 1997. He has contributed to the development of Phase Locked Loops for several generations of AMD microprocessors, as well as for the StrongArm and Alpha CPUs. He co-founded Matrix Semiconductor in 1998 (acquired by Sandisk in 2006) to commercialize 3D memories, and founded ZeroG Wireless in 2006. In his spare time, he builds discrete circuits, RF and otherwise, using anything from oxidized pocket change to ICs. In his other spare time, he enjoys playing chamber music and singing.