An eletronically controllable reflective lens to form can form the subreflector of a dual reflector antenna so and compensate electrically for main reflector surface distortions. It can also provide limited but extremely rapid steering of the secondary beam of the antenna. Such a device is useful in numerous spaceborne and ground-based antennas, and will become more useful as frequencies and antenna sizes continue to increase.The lens surface is formed of elements similar to those used in Frequency Selective Surfaces. Active electronic control devices, such as PIN diodes or FET's, are attached to the elements in such a way that activation of the device alters the electrical geometry of the reflective element, and therefore alters the relative phase of the reflected energy. Controlling different areas of the subreflector independently provides both compensation for main reflector surface distortions and beam steering.STATUS: Phase I Only
