Reconfigurable meta-mirror for wavefronts control: applications to microwave antennas.

A planar metasurface composed of electronically tunable meta-atoms incorporating voltage-controlled varactor diodes is proposed as a reconfigurable meta-mirror for wavefronts control in microwave antenna applications. The dispersion responses of the cells are individually tailored in the reconfigurable metasurface so as to overcome the bandwidth limitations of passive metasurfaces and also to control the phase characteristics. By controlling the bias voltage of the varactor diodes on the planar metasurface, the phase characteristics of reflectors can be engineered. The reconfigurable meta-mirror is utilized to implement three different types of reflectors. As such, a reflectarray, a cylindrical parabolic reflector and a dihedral reflector are numerically verified in microwave regime through finite element method. Moreover, experimental measurements are performed on a fabricated prototype to validate the proposed device. Frequency agility, beam deflection and beam focusing are the main functionalities demonstrated from the proposed reconfigurable meta-mirror.