The same microwave radiation that reheats pizza can be used to fry the electrical systems in cars, stopping them dead in their tracks. Emitted from a rooftop device, the radiation could be used by law enforcement officers to put an end to dangerous car chases or by military personnel as a non-lethal way of disabling vehicles that get too close for comfort.

"The idea is to warn an automobile some distance away from a high-value target like a military barrack or a communication center. If they don't comply, you just zap them and it prevents them from coming closer," said James Tatoian, CEO of Eureka Aerospace in Pasadena, Calif.

Tatoian and his team have been working on the device since 2003. The current prototype is about 5 feet long, 3 feet wide, a foot thick, and weighs just under 200 pounds. The technology uses the same kind of energy used in microwave ovens, but at a different frequency. Ovens typically operate at 2.45 Ghz, whereas the high-power car-stopping system is at 300 megahertz. In both cases, the radiation is above common radio frequencies and is not harmful to humans.

"There are no biological effects," said Tatoian. "We comply with every standard in the literature as far as biological impact." To disable cars, the device first generates energy that is amplified using a generator. The energy is converted to microwave radiation and then directed, by way of a specially designed antenna, at the offender in a narrow beam. The higher the frequency of the radiation, the more directed the beam, which allows the user to aim the energy at vulnerable car parts, such as light bulb filaments, lug nuts, frame bolts, or windshield antenna.