ELECTRONICS | 1887 | Radio waves are discovered by Heinrich Hertz. |
| 1894 | Oliver Lodge invents the ‘coherer’ for detecting radio waves. Marconi develops radio telegraphy. |
| 1897 | J. J. Thomson discovers the electron. |
| 1902 | US engineer Reginald Fessenden (1866–1932) develops radio telephony. |
| 1903 | Danish engineer Valdemar Poulsen (1869–1942) invents the arc transmitter for radio telegraphy. |
| 1904 | British engineer Ambrose Fleming (1849–1945) invents the diode thermionic valve. |
| 1906 | US engineer Lee De Forest (1873–1961) invents the triode thermionic valve. |
| US electrical engineer Greenleaf Pickard (1877–1956) patents the crystal detector for radios. |
| Fessenden introduces amplitude modulation in radio broadcasting. |
| 1911 | German physicist Karl Braun (1850–1918) invents cathode-ray tube scanning. |
| 1912 | Fessenden develops the heterodyne radio receiver. |
| 1919 | US electrical engineer Edwin Armstrong (1890–1954) develops the superheterodyne radio receiver. |
| 1921 | US physicist Albert Hull (1880–1966) invents the magnetron microwave-generating valve. |
| 1923 | Russian-born US engineer Vladimir Zworykin (1889–1982) invents the iconoscope television camera-tube. |
| 1928 | Scottish inventor John Logie Baird (1888–1946) and Vladimir Zworykin independently develop colour television. |
| 1930 | Swedish-born US electronics engineer Ernst Alexanderson (1878–1975) invents an all-electronic television system. |
| 1933 | US electrical engineer Edwin Armstrong (1890–1954) develops frequency modulation radio broadcasting. |
| 1947 | US physicists John Bardeen, Walter Brattain (1902–87), and William Shockley (1910–89) invent the point-contact transistor. |
| 1950 | US engineers develop the Videcon television camera tube. |
| 1953 | Chinese-born US computer engineer An Wang (1920–90) invents the magnetic core computer memory. |
| 1954 | US physicist Charles Townes (1915– ) and Soviet physicists Nikolai Basov and Aleksandr Prokhorov (1916– ) independently develop the maser. |
| 1958 | US electronics engineers Jack Kilby and Robert Noyce (1927–90) develop integrated circuits. |
| 1960 | US physicist Theodore Maiman (1927– ) invents the ruby laser. |
| 1961 | US electronics engineer Steven Hofstein develops the field-effect transistor. |
| 1971 | US electronics engineer Marcian Edward Hoff (1937– ) designs the first microprocessor (Intel 4004). |
| 1977 | US engineers transmit television signals along optical fibres. |