A novel compact MIMO dual‐mode filtering antenna array with wide bandwidth, high selectivity and good isolation is proposed. The filtering antenna unit consists of a patch radiator at the top layer coupled with a high‐order dual‐mode filter at the bottom layer through a rectangular slot in the middle ground layer. The fourth‐order filter adopts two E‐shape dual‐mode resonators to achieve wide bandwidth and high selectivity. A pair of filtering antenna units form a MIMO array with a distance of 0.2λg by using three interdigital lines in the middle to enhance the port isolation. Finally, a 1 × 2 MIMO filtering antenna array operating at 2.45 GHz is designed and fabricated, which shows wide fractional bandwidth of 24.5%, sharp skirt slope with a pair of radiation nulls, smooth realized gain of 4.5 dBi as well as high isolation more than 20 dB.

中文翻译：

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紧凑的双模宽带MIMO滤波天线阵列，具有高选择性和更高的隔离度

提出了一种新颖的紧凑型MIMO双模滤波天线阵列，具有宽带宽，高选择性和良好的隔离性。滤波天线单元由顶层的贴片辐射器和底层的高阶双模滤波器通过中间接地层中的矩形缝隙组成。四阶滤波器采用两个E形双模谐振器，以实现宽带宽和高选择性。一对滤波天线单元通过在中间使用三根叉指线来形成距离为0.2λg的MIMO阵列，以增强端口隔离度。最后，设计并制造了一个工作频率为2.45 GHz的1×2 MIMO滤波天线阵列，它显示出24.5％的宽分数带宽，带有一对辐射零点的尖裙边坡度，4.5 dBi的平滑实现增益以及高隔离度more大于20 dB。