Dual-Broadband Dual-Polarized Base Station Antenna Array With Stable Radiation Pattern

This letter presents an interleaved dual-broadband dual-polarized base station antenna array consisting of a lower-band element and two upper-band subarrays. L-shaped strips are loaded in the lower-band radiator to reduce its scattering effect on the upper-band radiation. Cross-dipoles fed by coupling technique are innovated for the upper-band radiator to achieve wide bandwidth. In addition, unshorted baluns are proposed to reduce the detrimental effect of the induced current on the radiation performance between the two bands. The lower- and upper-bands range from 660–970 MHz and 1.6–2.9 GHz, corresponding to 38% and 57.8% bandwidths, respectively. Very stable radiation patterns, wide bandwidths, and good port isolations are achieved for both bands.