This paper presents a high-performance multiple input and multiple output (MIMO) antenna comprising 2 × 2 configuration of radiating elements that is designed for sub-6 GHz applications. The proposed MIMO antenna employs four identical radiating elements. High isolation between the radiating elements and therefore reduced mutual coupling is achieved by spatially arranging the radiating elements in an orthogonal configuration. Also, a novel frequency selective surface (FSS) was employed to increase the gain of the MIMO antenna over a wide bandwidth from 3 to 6 GHz. This was achieved by locating the FSS above the antenna at a certain height. The FSS essentially enhanced the antenna's directivity, reduced back lobe radiation and mutual coupling. The antenna was fabricated on a standard Rogers RT Duroid 5880 dielectric substrate with a 0.8 mm thickness. The overall dimension of the MIMO antenna is 50 × 50 × 12.5 mm³ and it operates from 3.8 to 6 GHz, which corresponds to a fractional bandwidth of 41%. The proposed MIMO antenna has a measured peak gain of 4.8 dBi and inter radiation element isolation >20 dB. Its envelope correlation coefficient is <0.1 and diversity gain >9.9 (dB). These characteristics make the proposed MIMO antenna system suitable for 5G communication systems.

中文翻译：

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MIMO 配置中的高性能天线系统，用于 6 GHz 以下频谱上的 5G 无线通信

本文提出了一种高性能多输入多输出 (MIMO) 天线，包含 2 × 2 辐射元件配置，专为 6 GHz 以下应用而设计。所提出的 MIMO 天线采用四个相同的辐射元件。通过以正交配置在空间上布置辐射元件，实现了辐射元件之间的高隔离并因此降低了相互耦合。此外，还采用了新型频率选择表面 (FSS) 来提高 MIMO 天线在 3 至 6 GHz 宽带宽上的增益。这是通过将 FSS 放置在天线上方一定高度来实现的。FSS本质上增强了天线的方向性，减少了后瓣辐射和互耦。该天线是在厚度为 0.8 毫米的标准 Rogers RT Duroid 5880 介电基板上制造的。MIMO天线的整体尺寸为50 × 50 × 12.5 mm ³，工作频率为3.8至6 GHz，对应的分数带宽为41%。所提出的 MIMO 天线的测量峰值增益为 4.8 dBi，辐射元件间隔离度 >20 dB。其包络相关系数<0.1，分集增益>9.9（dB）。这些特性使得所提出的 MIMO 天线系统适用于 5G 通信系统。