A compact 4 element MIMO antenna operating in three Sub-6 GHz 5G bands is proposed. The single element antenna consists of a square-shaped patch where circular and rectangular-shaped slot cuts are incorporated. The single element is symmetrically arranged along the horizontal direction and in mirrored fashion along the vertical and diagonal direction. The 4 element MIMO antenna achieves a symmetric structure on top with the connected ground at back. With no extra isolation element, the proposed FR-4 based design achieves compact size of 0.39λ₀² (f₀ = 3.72 GHz) operating in three frequency bands ranging from (2.65%) 3.72–3.82 GHz, (2.33%) 4.65–4.76 GHz and (4.75%) 6.16–6.46 GHz. The satisfactory isolation amongst inter-elements (≥ 16 dB) with directional radiation pattern and an average gain of 2.5 dBi is attained for proposed bands. Furthermore, the antenna meets the MIMO diversity criteria by achieving DG > 9.7, ECC < 0.1, TARC < -10 dB, the ratio of MEG ≈ 1, and lastly channel capacity loss < 0.5 bits/s/Hz making it commercially viable for its use in wireless 5G devices using Sub-6 GHz bands.

提出了一种在三个 Sub-6 GHz 5G 频段中运行的紧凑型 4 单元 MIMO 天线。单元件天线由方形贴片组成，其中包含圆形和矩形槽切口。单个元素沿水平方向对称排列，沿垂直和对角线方向以镜像方式排列。4 单元 MIMO 天线实现了顶部对称结构，背面连接接地。由于没有额外的隔离元件，建议的基于 FR-4 的设计实现了 0.39λ ₀ ² (f ₀ = 3.72 GHz) 工作在三个频段，范围为 (2.65%) 3.72–3.82 GHz、(2.33%) 4.65–4.76 GHz 和 (4.75%) 6.16–6.46 GHz。对于建议的频段，具有定向辐射模式和平均增益为 2.5 dBi 的元件间 (≥ 16 dB) 之间的隔离令人满意。此外，该天线通过实现 DG > 9.7、ECC < 0.1、TARC < -10 dB、MEG 的比率 ≈ 1，以及最后的信道容量损耗 < 0.5 bits/s/Hz 来满足 MIMO 分集标准，使其在商业上可行用于使用 Sub-6 GHz 频段的无线 5G 设备。