Beam tilted base station antenna with electromagnetic gradient surface

A base station antenna for WCDMA band (1.920-2.170 GHz) application utilizing an electromagnetic gradient surface (EGS) is proposed. The EGS is applied as a reflector of 4×2 dipole array to tilt the beam with electrically without phase shifters on low-profile structure. Therefore the beam can be tilted with lower complexity, smaller size, and cheaper cost compared to conventional mechanical or electrical beam tilting methods. The EGS reflector is designed to provide 6° downward tilt angle of the main beam. The fabricated antenna exhibits 5.6 tilt angle with gain of 16.9 dBi at 2.045 GHz.