A Compact Beamsteering Metalens Array Antenna with Circularly Polarized Phased Array

In this work, a compact metasurface (MTS)-based lens (metalens) array antenna with a circularly-polarized (CP) phased array is proposed for low-cost beamsteering applications. The metalens array antenna is composed of three dual-polarized metalens elements each fed by a CP patch antenna. The transmission response of the designed unit cell for lens element under wide-angle oblique incidence with different polarization is detailly studied to transmit a CP wave efficiently. As a result, the proposed CP metalens array antenna achieves a 3-dB beamwidth coverage range of ±30° with the 3 dB axial ratio (AR) bandwidth of the CP feeding antenna well preserved.