Various decoupling methods were proposed and investigated for multiple-input multiple-output (MIMO) Base Station (BS) systems. These methods can effectively decouple the dual-polarized co-polar signal but fail to decouple the cross-polarized signal, similarly limiting the BS's overall decoupling performance. In this paper, different antenna arrays are designed to illustrate the coupling mechanism of cross-polarized BS antennas, and a comprehensive study of the relationship between antenna configurations and mutual couplings is conducted. It is shown that compact size antenna elements enlarge the edge-to-edge separation, and the loop-shaped dipole elements reduce the cross-polarization couplings. Finally, the array-antenna decoupling surface (ADS) method is applied in a 2×2 array composed of the designed antennas. Thanks to the improved antenna unit, the decoupling task is eased, and a better decoupling performance is achieved compared with the original ADS work.

针对多输入多输出 (MIMO) 基站 (BS) 系统提出并研究了各种去耦方法。这些方法可以有效地解耦双极化共极化信号，但无法对交叉极化信号进行解耦，同样限制了基站的整体解耦性能。本文设计了不同的天线阵列来说明交叉极化基站天线的耦合机制，并对天线配置与相互耦合之间的关系进行了综合研究。结果表明，紧凑尺寸的天线元件扩大了边到边的间隔，而环形偶极子元件减少了交叉极化耦合。最后，将阵列-天线去耦表面（ADS）方法应用于由设计的天线组成的 2×2 阵列。