Multibeam Antenna Based on Partially Reflecting Defected Metasurface

In this letter, a multibeam antenna based on metasurface (MS) is proposed. By employing the partially reflecting defected MS as the radiator, taking port 1 as an example, the beam with multiple sidelobes is focused in the direction of (3°, 33°) and the peak gain increases from 6.3 to 10.57 dBi. Also, a narrow beam with half-power beamwidth of 31° is obtained in a dimension of 1.5 λ 0 × 1.5 λ 0. When the antenna is fed from different ports separately, the beams are steered in different directions. Also, through inserting the vias between two-layer patches of the MS unit, the sidelobe is suppressed and the gain is improved. The results indicate that the antenna can operate at 7.5 GHz. When four ports are separately excited, the antenna can radiate four beams pointing at ( ϕ , θ ) = (3°, 33°), (93°, 33°), (183°, 33°), and (273°, 33°).