Cascaded Split-Ring Resonator for Decoupling of Broadband Dual-Polarized Base Station Antenna Array

A cascaded split-ring resonator (SRR) is introduced to reduce the mutual coupling of antenna elements in broadband dual-polarized base station array, which is printed on one side of a 1mm thickness FR4 substrate. By using of this type of cascaded SRR, the band gap used to reduce the mutual coupling of elements can be broaden remarkably, it then be used in dual-polarized base station antenna array. The simulated results show that this structure can improve the isolation between dual-polarized base station antennas over the band of 1.71GHz-2.69GHz (44.5% relative bandwidth), and narrow the half-power beam width (HPBW) of the array simultaneously, which can be used for the decoupling of 4G and 5G broadband dual polarization base station array in the future.