Broadband Hybrid Decoupling Method for a Dual-Polarized Antenna With High Isolation

This letter presents a hybrid decoupling technique to realize high isolation for dual-polarized dipole antennas. The proposed antenna consists of a cross-dipole on two horizontal layers, one in the x-axis direction directly fed by a coaxial line and its extended strip and another in the y-axis direction differentially excited by a wideband power divider. A wideband hybrid decoupling method is applied, and the designed antenna has a simulated port-to-port isolation of more than 52.4 dB in the overlapped -10 dB impedance wideband of 1.69-2.73 GHz (47.1%). The fabricated prototype obtains a high port-to-port isolation of more than 48.3 dB over the 1.73-2.73 GHz (44.8%) frequency band. At the same time, the antenna has a stable radiation pattern, realized gains of 8.6 +/- 0.7 dBi at Port 1 and 8.7 +/- 0.6 dBi at Port 2, and an average radiation efficiency of 86.2%. The above characteristics indicate that the proposed antenna qualifies as a candidate for the base station antenna system in the 1.7-2.7 GHz frequency band.