A radar that uses a plasma to direct the beam is being developed for guided missiles by UK technology company Qinetiq and the system's inventor, Oxford University-based Plasma Antenna.

The antenna differs from electronically scanned phased array or mechanically steered planar array by using a conductive electron cloud – the plasma – inside the silicon wafer that makes up the antenna to reflect radio-frequency (RF) energy in a particular direction.

Plasma Antenna has filed six patents for the technology, but is still reticent about how it works. Physically, the antenna is a horizontal silicon wafer with conductors on both of its flat surfaces.

The wafer produces a localised plasma, using "plasma diodes", that forms an RF mirror, which deflects a radar beam generated at the mirror's focal point. The electriconically movable and shapable mirror can steer and focus the beam in any direction. The antenna would operate over a wide range of frequencies and wavelengths.

"In six months' time we hope to have a working demonstrator. Then we will be able to take orders," says Plasma Antenna founder Dr David Hayes.

Source: Flight International