Sir John Ambrose Fleming (November 29 1848 - April 18 1945)
sometimes also listed as Ambrose J. Fleming
English electrical engineer.
Born in born in Lancaster. Educated at University College School, London and UCL. Lecturer at a number of universities including Cambridge, Nottingham and UCL. Consultant to the Marconi Wireless Telegraph Company, Swan, Ferranti and later the Edison Electric Light Company. Knighted in 1929.
The inventor of the two-electrode radio rectifier, he called it the thermionic valve in 1904 (also called the vacuum diode, kenotron, thermionic tube, and Fleming valve), the basis for the vacuum tube in 1906 with a amplifier grid invented by Lee De Forest. Fleming also contributed in the fields of photometry, electronics, wireless telegraphy and electric measurements