Tri-Band Dual-Polarized Shared-Aperture Antenna Array for Base Station Applications

A tri-band dual-polarized shared-aperture antenna array is proposed, in which a rotated double M-shaped branch (DMB) and four pairs of stubs are designed to suppress the scattering effect of low-band radiation. This antenna array consists of two low-band (LB) antennas and four mid/high-band (M/HB) antennas. The principle of rotated DMB is explained. The measured results show that the aperture-shared antenna array achieves impedance bandwidths of 51.0% (1.6 GHz to 2.7 GHz), 16.2% (3.46 GHz to 4 GHz), and 8.3% (4.6 GHz to 5 GHz). Good decoupling characteristics are observed. The isolation of LB exceeds 25 dB, MB exceeds 20 dB, and HB is more than 30 dB, achieving a good level of isolation. Moreover, very stable radiation patterns are achieved over the whole band, which could be a good candidate for modern base station applications.