Spread-spectrum and ultra-wideband (UWB) technology arose during the Second World War. Actress Hedy Kiesler Markey (better known by her screen name, Hedy Lamarr) and George Antheil invented a frequency-hopping secret communication system. [1] The Figure below shows their frequency hopping transmitter. A record tape encodes a unique coding pattern to a network of tuning capacitors controlling a variable frequency carrier oscillator. The signal is thus virtually impossible to decode without knowledge of the frequency hopping pattern. The lack of regard for Lamarr’s invention at the time is evidenced by the fact that it was promptly allowed and published instead of being kept confidential for the duration of the conflict.
A classic example of an invention ahead of its time, spread spectrum and ultra-wideband technologies did not come into vogue until after Lamarr’s patent had already expired.
More comprehensive histories of the development of spread spectrum and ultra-wideband technology are available elsewhere. [2], [3], [4], [5]
[1] Hedy Kiesler Markey and George Antheil, Secret communication system, US Patent 2,292,387, August 11, 1942.
[3] See “Spread Spectrum History” at http://www.sss-mag.com/shistory.html
[4] See “Female Inventors – Hedy Lamarr” at http://www.inventions.org/culture/female/lamarr.html
3 thoughts on “RTLS: The First Ultrawideband Wireless System”
I agree that Hedy’s invention was ahead of its time, but it was also not unique. I used to work in the spread spectrum field and wrote a book about the 1942 invention. You can see more at http://www.robsbookshop.com
Interesting. Here’s a direct link: http://www.robsbookshop.com/page31.html