Lucien Lévy
From Wikipedia, the free encyclopedia
Lucien Lévy | |
|---|---|
 Lucien Lévy | |
| Born | 11 March 1892 Paris |
| Died | 24 May 1965 (aged 73) |
| Occupation | Engineer |
Lucien Lévy (French pronunciation: [lysjɛ̃ levi]; 11 March 1892 – 24 May 1965) was a French radio engineer and radio receiver manufacturer. He invented the superheterodyne method of amplifying radio signals, used in almost all AM radio receivers. His patent claim was at first disallowed in the United States in favour of the American Edwin Howard Armstrong, but on appeal Lévy's claim as inventor was accepted in the US.
Lucien Lévy was born in Paris on 11 March 1892.[1][2] He attended school in Paris at the Collège Rollin, then the Collège Chaptal. He obtained his diploma as an engineer from the École supérieure de physique et de chimie industrielles de Paris.[1]
World War I
During World War I (1914–18) Lévy was assigned to Colonel Gustave-Auguste Ferrié as sapper-telegraphist.[2] Captain Paul Brenot headed the second group of the Military Telegraphic Service. Members of the group included Henri Abraham, Maurice de Broglie, Paul Laüt and Lucien Lévy.[3] He was made head of the Eiffel Tower Military Radio Telegraphy laboratory in 1916. The laboratory was in a wooden barracks on the Champ de Mars, and used the Eiffel tower as an antenna for 100 kW radio transmissions. Levy developed in turn the first low frequency amplifier, which made it possible to listen to the enemy's telephone conversations, ground-based telegraphy, the first airplane receiver with vacuum tubes, the first wireless telegraphy station for automobiles and the superheterodyne receiver.[1]
Superheterodyne invention
The original concept of Amplitude Modulation (AM) radio was developed by the Canadian-born Reginald Aubrey Fessenden, who invented the word "heterodyne" from the Greek words heteros (other) and dynamis (force).[4] In an improvement over Fessenden's design, the superheterodyne principle uses a variable oscillator and a fixed narrow filter to amplify an incoming AM radio signal. Lévy filed a patent application for the superheterodyne principle in August 1917 with brevet n° 493660.[5] The American Edwin Howard Armstrong also filed a patent in 1917.[4] Levy filed his original disclosure about seven months before Armstrong's.[6] Levy later claimed that Armstrong had stolen his idea while serving in Paris in the signal corps.[7] Lévy described an improved version in a second patent in 1918. The German inventor Walter H. Schottky also filed a patent in 1918.[5]
The US refused to recognise these patents, and recognised Armstrong as the inventor.[5] Armstrong's US Patent 1,342,885[8] was issued on 8 June 1920.[6] AT&T paid US$20,000 in 1920 for Levy's first patent application in the hope that it would be judged to be fundamental, as well as his corresponding US patent application. After various changes and court hearings Levy was awarded a US patent No 1,734,038[9] that included seven of the nine claims in Armstrong's application, while the two remaining claims were granted to Alexanderson of GE and Kendall of AT&T. This had no effect in France, but a German patent was issued to Levy on 1 October 1931.[6]
