X-band microwave beam steering using a plasma mirror

The Naval Research Laboratory has been investigating the use of a planar conductive sheet of plasma, called an Agile Mirror, as an electronically steerable antenna. The objective of this program is to produce a beam steering element for an X-band, multi-function radar. In such a system microwaves from a fixed source would be bounced off of the plasma toward a target. The beam would then be steered by changing the orientation of the plasma sheet on a pulse by pulse basis. The radar return signal would come back along the same path. The plasma distribution is generated in pressure chamber by electron ionization. Experiments have shown that such a plasma sheet can be formed, turned on or off in 10 microseconds, and maintained in a given orientation for several milliseconds. The planar plasma geometry would enable wide instantaneous bandwidth beam steering in the X-band for ship or airborne multifunction radar applications. The concept along with the present status of the Agile Mirror program are presented.