In this article, a microstrip line fed 2-port circularly polarized multiple-input-multiple-output (MIMO) antenna is designed and fabricated. A novel ground structure and radiating patches are used to achieve the circularly polarized radiated field by the MIMO antenna. To improve the isolation between two ports, a meandered U-shaped narrow metallic strip is placed between the asymmetric Z-shaped radiating elements. The proposed MIMO design demonstrates the impedance bandwidth (S₁₁ ≤ −10 dB) of 90.94% (3.04-8.11 GHz). The axial ratio bandwidth ≤3 dB is found to be 32.10% (4.42-6.11 GHz). The diversity parameters such as envelope correlation coefficient, diversity gain, mean effective gain, total active reflection coefficient and channel capacity loss are also calculated to make the proposed design more reliable for 5G applications. This antenna is made compact and small which carries the dimension 24 × 24 × 1.6 mm³. The entire investigation is first modeled using the simulation software CST Microwave Studio and then verified with the measured results.

中文翻译：

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具有新颖接地结构的紧凑型圆极化 MIMO 印刷天线，适用于宽带应用

在本文中，设计并制造了一种微带线馈电 2 端口圆极化多输入多输出 (MIMO) 天线。MIMO天线采用新型接地结构和辐射贴片实现圆极化辐射场。为了提高两个端口之间的隔离度，在不对称的 Z 形辐射元件之间放置了一个弯曲的 U 形窄金属条。提议的 MIMO 设计证明了阻抗带宽 (S ₁₁ ≤ −10 dB) 的 90.94% (3.04-8.11 GHz)。发现轴比带宽≤3 dB 为32.10% (4.42-6.11 GHz)。还计算了包络相关系数、分集增益、平均有效增益、总有源反射系数和信道容量损失等分集参数，以使所提出的设计在 5G 应用中更加可靠。该天线体积小巧，尺寸为 24 × 24 × 1.6 mm ³。整个调查首先使用仿真软件 CST Microwave Studio 建模，然后用测量结果进行验证。