A Wideband Polarization Reconfigurable Antenna Using Quasi-Cross-Shaped Coupling Slot

A quasi-cross-shaped coupling slot antenna with a Wilkinson power divider network is proposed to realize the wideband polarization reconfigurable between linear polarization (CP), left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). The quasi-cross-shaped coupling slot generates two orthogonal linear polarization with high isolation. Four pairs of PIN diodes are used in four branches of the Wilkinson power divider network to alter the current flow path so as to generate a phase difference of 0° or $\pm 90^{\text{o}}$ and achieve the polarization reconfiguration. The results show that the proposed antenna has a 10-dB impedance bandwidth of 2.80-3.54GHz (0.74GHz, 23.3%) for LP and 2.82-3.49GHz (0.67GHz, 21.2%) for CP. The 3-dB axial ratio (AR) bandwidth is 2.92-3.43GHz (0.51GHz, 16.1%) for LHCP and 2.88-3.43GHz (0.55GHz, 17.4%) for RHCP. In addition, the antenna achieves a high average realized a gain of 9.1dBi.