Michael Phelan / Sheffield

Semi-active coverings could make aircraft invisible to radar

Semi-active stealth coatings on aircraft could make them invisible to radar or even project phantom aircraft velocities and positions, say researchers at the University of Sheffield's department of electronic and electrical engineering in the UK.

The composite panels have electronic emitters embedded in their front and rear surfaces that can project a false reflection of detected radar signals. Prof Barry Chambers says the panels can "cancel Doppler signals and even 'reflect' phantom signals to emulate other aircraft types or velocity signatures".

The system works by returning an artificial signal generated by the two surfaces of the panel that is outside the frequency limits of the radar receiver. Chambers says the panels are lighter than some traditional radar absorbent coatings and can also be easily activated or deactivated "with the flick of a switch", enabling an aircraft to hide its stealth capabilities until they are required.

The university has been developing the technology with external partners for about six years and says it could be retrofittable to older aircraft.

Source: Flight International