Multiple-input and multiple-output (MIMO) systems utilize multiple antenna elements to improve channel capacity and achieve higher data rates. The successful implementation of MIMO systems requires low mutual coupling between antenna elements to reduce the envelope correlation coefficient (ECC) at the operating frequency. In this paper, we introduce a mutual coupling suppression technique using an open stub meandered (OSM) bandstop filter (BSF) design for MIMO applications. The OSM-BSF is optimized and implemented on the ground plane side of a two-element patch array. The designed filter provides high isolation of 60 dB at 2.4 GHz across a 30% bandwidth. A parametric study of antenna element spacing was carried out, showing at least 40 dB of mutual coupling suppression in the antenna array, irrespective of the antenna element spacing. A two-element antenna array prototype with OSM-BSF was fabricated and tested. Measurements showed that ≥ 57 dB isolation was achieved using OSM-BSF. Besides, the fabricated array provides a low ECC of 0.0093 at 2.42 GHz, while maintaining edge-to-edge spacing as little as $0.19\lambda _{0}$ .

中文翻译：

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曲折开路短截线滤波技术在天线阵列中的互耦抑制

多输入多输出（MIMO）系统利用多个天线元件来提高信道容量并实现更高的数据速率。MIMO系统的成功实施要求天线元件之间的相互耦合低，以降低工作频率下的包络相关系数（ECC）。在本文中，我们介绍了一种互开耦合抑制技术，该技术使用了针对MIMO应用的开放式存根蜿蜒（OSM）带阻滤波器（BSF）设计。OSM-BSF在两元素贴片阵列的接地平面侧进行了优化和实现。设计的滤波器可在30％带宽内在2.4 GHz时提供60 dB的高隔离度。进行了天线元件间距的参数研究，显示了天线阵列中至少40 dB的互耦抑制，而与天线元件间距无关。制作并测试了带有OSM-BSF的两元件天线阵列原型。测量表明，使用OSM-BSF可以达到≥57 dB的隔离度。此外，所制造的阵列在2.42 GHz时可提供0.0093的低ECC，同时保持边到边的间距小至 $ 0.19 \ lambda _ {0} $ 。