Steerable ultra-thin directive antenna from a metamaterial-based subwavelength cavity

We report the design of a steerable directive antenna using a resonant metamaterial-based subwavelength cavity. The cavity is made of a conventional ground plane and a composite metamaterial acting us a partially reflective surface. The antenna is a rectangular microstrip patch designed to operate near 10 GHz. The composite metamaterial is made of a variable capacitive grid and a constant inductive grid. Simulation and measurements show a deflection of the antenna beam of about plusmn20deg for a cavity of thickness about lambda/30.