: Bomb jammer

: Bomb jammer
16:59 08 May 2006
NewScientist.com news service
Barry Fox

For over 30 years, Barry Fox has trawled through the world's weird and wonderful patent applications, uncovering the most exciting, bizarre or even terrifying new ideas. His column, Invention, is exclusively online. Scroll down for a roundup of previous Invention articles.
Bomb jammer

Jimmy Hendrix turned feedback into an art form – sticking his guitar close to a speaker so that it picked up its own sound and generated deafening shrieks.

Now a US inventor is patenting a way to defeat remote-controlled explosives using the same trick. A series of transmitters would create a self-sustaining bubble of radio frequency noise to prevent terrorists from sending a trigger signal to a hidden bomb.

In his patent filing, James Cornwell of Virginia, US, claims that existing radio jamming devices are flawed because they leave gaps that let trigger signals sneak through. His system would use up to four radio transmitters and receivers placed around a risk area. When a wide frequency of noise is fed to one of the transmitters, all the receivers pick it up and feed the signal to their respective transmitters. Soon the feedback loop completely blankets the risk area with powerful radio energy.

The method could produce a bomb-blocking bubble up to 1 kilometre square, Cornwell reckons. This would leave bomb disposal experts safe in the knowledge that no one could trigger an explosive device while they are working to defuse it.

Read the full patent here.

From http://tinyurl.com/kdnt5 newscientisttech

Sounds very useful, if it works in actual practice.