William Dubilier

He demonstrated radio communication at Seattle's Alaska–Yukon–Pacific Exposition on June 21, 1909; ten years before the first commercial station operated.

[1] A graduate of Cooper Union, he was the first to use sheets of naturally occurring mica as the dielectric in a capacitor.

[2] Mica capacitors were widely used in early radio oscillator and tuning circuits because the temperature coefficient of expansion of mica was low, resulting in very stable capacitance – mica capacitors are still used where exceptional temperature stability is needed.

He founded the Dubilier Condenser Company in New York in 1920.

[3] His son Martin H. Dubilier also became a prominent inventor and company founder.