A novel low-profile, dual-band, dual-polarization broadband array antenna for 2G/3G base station

In this paper, a novel dual-band broadband array antenna with low profile and dual polarization is proposed and developed. The array is formed by arc-probe-fed annular ring elements and pairs of cross microstrip dipoles nested together. The bandwidth of the annular ring antenna is improved through arc-probe-fed technique. The measured impedance bandwidths determined by VSWR≪2 cover 806∼960 MHz and 1710∼2170MHz. The port isolation and the symmetry of the radiation for the lower band are improved by the “anti-phase and dual-feed” technique which also reduces the cross polarization level. The influences on the radiation patterns of upper band caused by the phase error are invested and the radiation patterns are improved through the phase compensation. In the end, the array is designed and the simulated and measured results are presented. The proposed array antenna is highly applicable to the base station of multi-band operations.