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About RF Cafe

Kirt Blattenberger - RF Cafe WebmasterCopyright
1996 - 2016
Webmaster:
Kirt Blattenberger,
 BSEE - KB3UON

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

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Hedy Lamarr Google Doodle

Hedy Lamarr and a Secret Communication System - RF CafeSpread Spectrum: Hedy Lamarr and the Mobile Phone - RF CafeToday's Google homepage features one of their famous Doodles that honors the accomplishments of Austrian-born actress Hedy Lamarr. You might wonder why I would point this out on an engineering website. Here's why: Aside from being one of the most well-known film stars of her era, Ms. Lamarr was also an inventor and received U.S. patent number US2292387* jointly with composer/pianist Antheil George for a "Secret Communication System." We refer to her invention today as frequency-hopping spread spectrum.

Given that Google is heavily invested in spread spectrum technology and the company is staffed with some of the world's top engineers, it is no wonder the Google Doodle dedicates more than half of the presentation to Hedy Lamarr's technical accomplishments. You can watch the entire Doodle below, but here I show a few key screen cels of the story board.

Hedy Lamarr Google Doodle (chemist) - RF Cafe   Hedy Lamarr Google Doodle (inventing Fizzies?) - RF Cafe

Hedy Lamarr experimented with chemistry and attempted to develop a cube that when dropped in water would produce a Coca Cola-type drink - anyone else out there remember Fizzies?

Hedy Lamarr Google Doodle (WWII torpedo problem) - RF Cafe   Hedy Lamarr Google Doodle (working with Antheil George) - RF Cafe

Hedy Lamarr was upset over the lack of success Allied submarines were having against Axis subs. She thought maybe if torpedoes were able to be steered remotely, the kill rate would be much greater. But, vulnerability to signal jamming would be an issue. Spring boarding off of work done by Antheil George with automated musical instruments, Ms. Lamarr came up with the idea of rapidly changing transmit frequencies in a manner that would prevent enemy forces from blocking the signals.

Hedy Lamarr Google Doodle (frequency hopping spread spectrum idea) - RF Cafe   Hedy Lamarr Google Doodle (frequency hopping torpedo control) - RF Cafe

US2292387, applied for on June 10, 1941 - before the United States even officially entered World War II on December 7 of that year - detailed just such a frequency hopping system. The Morse code-like control signal was effectively a digital data stream, most likely without any form of error detection/correction. Unfortunately, the U.S. Navy did not manage to implement the scheme before the war ended.

Hedy Lamarr Google Doodle (US2292387 notebook outline) - RF Cafe   Hedy Lamarr Google Doodle (accomplishments) - RF Cafe

Hedy Lamarr Google Doodle - November 9

* Note that the patent lists her given (born) name of Hedwig Eva Maria Kiesler.

"Fizzies" production video - Hedy Lamarr should have patented that idea, too!

Happy Birthday Hedy Lamarr! - RF Cafe

Hedy Lamarr RF Cafe Day in History logo.

 

 

Posted November 9, 2015