Asad A. Abidi, Chancellor’s Professor, Electrical Engineering
University of California, Los Angeles
Abstract: Edwin Armstrong’s name is associated with the superheterodyne receiver and with wideband FM. But he could never have persuaded skeptics of the value of either system concept without developing circuits that would demonstrate these systems in practical form. Working with the recently invented triode vacuum tube, Armstronginvented new circuits for every block of the system, often from first principles. He was acutely aware that for the radio receiver to enter every home, the circuits should provide superior reception at the lowest possible cost. His earliest circuit inventions date to his undergraduate years at Columbia University, although his output of circuits continued through the 1920s.
I will use a modern approach to interpret Armstrong’s circuits, some of which use a single vacuum tube for multiple functions. I wish to make the case that Armstrong is a pioneer not only of communications architectures but also one of the first electronic circuit designers. His circuit concepts live on a century later, today in the ubiquitous radios-on-a-chip.