A low-profile polarization reconfigurable antenna

In this paper, a novel multi-polarization reconfigurable antenna using an artificial magnetic conductor (AMC) reflector is proposed. The antenna consists of seven pairs of dipoles distributed on both the top and bottom surface uniformly. By turning ON or OFF PIN diodes connected with different dipoles, seven linear polarizations (LPs) at a 25.7 deg interval in azimuth plane can be obtained. The designed AMC unit pattern is a circular ring surrounded by seven sectors, which is helpful to balance the bandwidth and gains for seven LPs. By designing a plane with circular AMC array and employing it as a reflector to enhance the directivity, the reported antenna has a wide impedance bandwidth between 4.21 and 5.32GHz (23.1parcent). The overall profile is $0.133\lambda_{L}$ at 4.2GHz.