Radar systems work by sending out radio waves and using the echoes that bounce back to create an image of an object. Some radar systems use electronics to actively steer their outgoing radio waves, instead of just mechanically sweeping a beam in a fixed pattern. This lets them simultaneously scan the sky for objects and track specific ones with high accuracy. But the complex devices normally needed to steer radio waves around, known as phase shifters, make such electronically scanning radar expensive and bulky.
But start-up company Echodyne is working on a device that is compact and cheap enough to be used widely thanks to the relatively new technology of metamaterials, the Review says.
Metamaterials provide a way to get around many of the physical limitations that have previously defined how engineers could control radio, light, and sound waves. For example, while conventional lenses need their characteristic shape to bend light rays into focus, a metamaterial lens can bend light the same way while being perfectly flat.
Metamaterials are made from repeating structures that are smaller than the wavelength of the electromagnetic radiation being manipulated. Echodyne makes its metamaterials by tracing out repeating patterns of copper wiring on an ordinary circuit board.
A board with multiple layers of such wiring can direct radar beams. And applying different voltages to some parts of the wiring makes it possible to actively control the beam as a phase shifter would. “Any printed circuit board manufacturer could produce these,” says [CEO Tom Driscoll.
Driscoll says the technology could make scanning radar a standard sensor for vehicles and robots and is a step up from spinning laser sensors as used by Google’s prototype driverless car. Spinning laser sensors are highly effective, but their range decreases in fog or snow. Radar doesn’t have that limitation.