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 World Wide Web (Internet) was largely an unknown entity at
the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps
while tying up your telephone line, and a nice lady's voice announced "You've Got
Mail" when a new message arrived...
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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 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
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.
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 - November 9
* Note that the patent lists her given (born) name of
Hedwig Eva Maria Kiesler.
production video - Hedy Lamarr should have patented that idea, too!
Hedy Lamarr RF Cafe Day in History logo.
Posted November 9, 2015
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