A miniaturized broadband planar monopole multiple‐input‐multiple‐output (MIMO) antenna is proposed for the 3.5 GHz frequency band of the Long‐Term Evolution Advanced application. Two novel broadband metamaterial split‐ring resonator units are used to reduce the mutual coupling of the MIMO antenna, also expanding the antenna impedance bandwidth. The size of the whole antenna is 47.5 mm × 40 mm × 1.6 mm (1.15λ_g × 0.97λ_g × 0.039λ_g) and the center distance between the two antenna elements is only 0.25λ₀. The measured results agree well with the simulated ones. The measured 10‐dB impedance bandwidth is 3.35 to 3.78 GHz (12.3%), and the isolation is up to 15 dB within the bandwidth.

中文翻译：

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具有超高隔离度的基于超材料的紧凑型宽带平面单极MIMO天线

针对长期演进高级应用的3.5 GHz频段，提出了一种小型化的宽带平面单极多输入多输出（MIMO）天线。两个新颖的宽带超材料裂环谐振器单元用于减少MIMO天线的相互耦合，还扩大了天线的阻抗带宽。整个天线的尺寸是47.5毫米×40mm的×1.6毫米（1.15λ_克 ×0.97λ_克 ×0.039λ_克）和所述两个天线元件之间的中心距为只有0.25 λ ₀。测量结果与模拟结果吻合良好。测得的10 dB阻抗带宽为3.35至3.78 GHz（12.3％），隔离度在带宽内高达15 dB。