Self-Decoupled Dual-Band Shared-Aperture Base Station Antenna Array

A new decoupling concept for dual-band shared-aperture base station antenna arrays is proposed. By loading arrow-shaped decoupling structures in the hollowed regions of the low-band (LB) loop dipole arms, the LB antenna can yield partial reflection to the high-band (HB) antennas, canceling the HB-coupled wave. A dual-band base station antenna array is designed, fabricated, and measured based on this decoupling concept. With decoupling, the HB radiation patterns are restored. The copolarized in-band couplings between the HB antennas are reduced by about 9 dB, reaching >26.9 dB. The proposed antenna array possesses both cross-band and in-band decoupling abilities, without extra decoupling layer.