A Broadband Dual-Polarized Crossed Dipole

A dual-polarized crossed dipole with broad impedance bandwidth and high port-isolation is introduced in this paper. The crossed dipole antenna consists of four radiation arms, a metallic reflector and a balun. The radiation pattern can be widened with radiation arms tipped down at a 7 percent tilt. To achieve the unidirectional radiation, a metallic reflector (80mm
^x
80mm
^x
3mm) is mounted at the back of the antenna. The balun used in this paper is different from the balun mentioned in other literature, it can convert the coaxial feed structure to the differential feed structure., thus improving the performance of the dual polarization configurations. The simulated results show that the proposed antenna has stable symmetric unidirectional radiation patterns in the operating frequency band from 2.25 to 3.12 GHz with the port-to-port isolation better than 35dB. By setting the phase difference between the two ports to 90°, circularly polarized pattern polarization pattern can be obtained.