At its laboratory on the campus of Texas Tech University in Lubbock, chief executive Don Stull showed off the long, metallic microwavedevice that resembles an industrial production line.
"The cloak we demonstrated in 2006 as a kind of microwavedevice would be very poor, but this one gets us to something that could be potentially useful, " Prof Smith said.
This device, developed at the Joint Non-Lethal Weapons Directorate in Quantico, Virginia, is a microwave transmitter the size and shape of a small satellite dish that pivots on top of an armoured car.