This brief demonstrates the use of metamaterial absorber (MA) to achieve high isolation between two patch antennas in a 2-element multiple-input–multiple-output (MIMO) system operating at 5.5 GHz resonant frequency useful for WiMAX application. The proposed flower shaped MA, designed on a $9\times 9$ mm2 FR-4 substrate with 1 mm thickness, exhibits near unity normalized impedance at 5.5 GHz with an absorptivity of 98.7%. A four element array of the MA is arranged in the form of a line in the middle of the two radiating patches in order to suppress the propagation of surface current between them at the operating frequency. Using the proposed flower shaped MA, an isolation of nearly 35 dB is achieved. The MIMO structure is studied in terms of return loss, isolation, overall gain, radiation pattern, envelope correlation coefficient (ECC), diversity gain (DG), total active reflection co-efficient (TARC), etc. The structure is finally fabricated and measured to show good agreement with the simulated results.

中文翻译：

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在 5.5 GHz WiMAX 频段使用新型花形超材料吸收器改善 MIMO 天线的隔离度

本简介展示了使用超材料吸收器 (MA) 在 2 单元多输入多输出 (MIMO) 系统中的两个贴片天线之间实现高度隔离，该系统在 5.5 GHz 谐振频率下工作，对于 WiMAX 应用非常有用。拟议的花形 MA 设计在 9 美元×9 美元 mm2 FR-4 基板上，厚度为 1 毫米，在 5.5 GHz 下表现出接近统一的归一化阻抗，吸收率为 98.7%。MA的四元件阵列以线的形式排列在两个辐射贴片的中间，以抑制它们之间在工作频率下的表面电流传播。使用建议的花形 MA，实现了近 35 dB 的隔离。从回波损耗、隔离度、总增益、辐射图、包络相关系数 (ECC)、