Design of a Reconfigurable Phase Gradient Metasurface for Beam Steering Applications

This paper presents a novel, reconfigurable phase gradient metasurface (PGMS) for beam steering applications. By embedding varactors into the unit cells of a three-layered metasurface and adjusting the biasing in each column, a completely reconfigurable and tunable PGMS has been achieved. The structure is capable of steering a main beam from broadside to 48 degrees in either direction and can tune to intermediate angles by adjusting the phase gradient at the aperture interface. Furthermore, the surface can operate at broadside as a tunable frequency selective surface (FSS). This highly reconfigurable design overcomes limitations in previous static, fixed-beam PGMS implementations, and thus offers a new radome structure capable of operational versatility and selective beam steering. Applications include radar antennas as well as other directive beam steering scenarios and this allows for enhancement of conventional phased array systems.