Compact Dual-Polarized Shared-Dipole Antennas for Base Station Applications

Crossed-dipole (CD) antennas have been widely employed for dual polarization in wireless communication systems in recent years. In this paper, a novel design concept of dual-polarized shared-dipole (DPSD) antenna is presented. Different from the traditional CD antennas, the arms of the DPSD antenna are shared for two orthogonal polarizations. This design technique leads to significant size reduction and high isolation compared to the traditional CD antennas. The operation principle of the proposed antenna is theoretically analyzed. To validate the presented design concept, two novel DPSD antennas are designed, fabricated, and measured. The first design is a four-port DPSD antenna, which is a straightforward demonstration of the operation principle of the DPSD antenna. The second design is a highly integrated DPSD antenna, which avoids the use of a feed network and provides a simple configuration to design the dual-polarized antenna. Both of the DPSD antennas are designed to operate at 1.7-2.7 GHz for base station applications. The simulated and measured results confirm that the two DPSD antennas have wide bandwidth with VSWR <; 1.5 and isolation > 35 dB dB. In addition, stable gain and half-power beamwidth are obtained with the variance less than ±0.55 dB and ±3.5°, respectively.