Phase-gradient metasurfaces for beam steerable antennas

Metasurfaces presenting a phase-gradient are designed at 10 GHz and are proposed to steer an antenna's radiated beam from broadside towards endfire direction. The metasurfaces are composed of both inductive and capacitive grids and the phase-gradient is achieved by modifying the elements in the inductive grid. Such phase-gradient metasurfaces are utilized as Partially Reflecting Surfaces (PRS) in Fabry-Pérot (FP) leaky-wave antennas (LWAs). Depending on the gradient used, beam steering up to 60° has been observed numerically and verified experimentally.