A compact and dual-polarized microstrip array antenna for mini base station applications

The design of a 2×2 compact dual-polarized microstrip array antenna with high isolation and low cross-polarized radiation characteristics for mini base station applications is presented in this paper. The array antenna provides an impedance bandwidth of 7.7% for VSWR < 1.4, operating around 2.6 GHz. The total thickness of the array antenna is about 0.052λ
0
and the array dimension is 160×160 mm
²
. A gain of higher than 12 dBi is achieved within the bandwidth. By introducing the dual-feed technique and modifying the shape of patches, the isolation between the two polarized ports is higher than 30 dB over the entire bandwidth. The cross-polarization levels in both of the E and H planes are all less than −30 dB.