Assertion: fet | /r/HasProperty | patented by julius edgar lilienfeld
Facets:
value: in 1934
type: TEMPORAL
value: in 1926
type: TEMPORAL
value: by oskar heil
type: OTHER
Source sentences:
text: The field-effect transistor was first patented by Julius Edgar Lilienfeld in 1926 and by Oskar Heil in 1934, but practical semiconducting devices (the junction field-effect transistors [JFETs]) were developed later after the transistor effect was observed and explained by the team of William Shockley at Bell Labs in 1947, immediately after the 20-year patent period eventually expired.