|The Improbable Inventors of Frequency-Hopping Radio
She was gorgous, glamorous and talented. And she had a mind for
technology. In 1941 actress Hedy Lamarr, along with the avant-garde
composer and musician George Antheil, filed for a patent to cover their
"Secret Communications System," a device designed to help the U.S. military
guide torpedoes by radio signals that would continually jump from one frequency
to another, thus making enemy interception and jamming difficult.
In Hollywood she met Antheil, who helped her figure out a way to synchronize the frequency hopping between the radio transmitter and receiver. Their invention, which they gave to the U.S. government for free, called for two paper rolls, similar to those used in player pianos, punched with an identical pattern of random holes. One of the rolls would control the transmitter on the submarine while the other would be launched with the receiver on the torpedo. Though ingenious, the device was deemed too cumbersome for use in World War II.
Still, the seminal idea of frequency hopping lingered. By the late 1950s U.S. Navy contractors were able to take advantage of early computer processors for controlling and synchronizing the hopping sequence. Since then, the U.S. military has deployed more sophisticated techniques with ever faster processors in costly classified devices, including satellite communications systems. And today the technology has become widespread in cell phones and in personal communications services (PCS) among other civilian applications.