Abstract Compact antennas with robust on-body performance are achieving more interest for wearable sensor nodes. In this paper, a modified aperture coupled multiple input multiple output (MIMO) antenna operating at 2.45 GHz industrial scientific and medical (ISM) band is presented for wearable devices. 8-shaped radiator with L-shaped ground slot is used to miniaturize the antenna dimensions. A dielectric reflector is added below the antenna to reduce the back radiations towards the body tissue. On-body performance is analysed on three layered equivalent tissue phantom model. Antenna shows reflection coefficient of −40 dB, efficiency of 58% and directivity of 6.7 dBi when operated in close proximity of body tissue with dielectric reflector. unidirectional radiation pattern and low specific absorption rate makes antenna suitable for on-body communication. Further, diversity performance is measured in terms of envelope correlation coefficient (ECC) and diversity gain (DG). Value of ECC is 0.045 and DG is 9.7 dB at 2.45 GHz. Antenna robustness is examined by bending the structure along x-axis. Performance of the proposed structure makes it a suitable candidate for on-body communication.

中文翻译：

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用于体上通信和增强介质背反射器性能的孔径耦合 MIMO 天线的设计

摘要 具有强大的在体性能的紧凑型天线正在引起可穿戴传感器节点的更多兴趣。在本文中，提出了一种用于可穿戴设备的改进的孔径耦合多输入多输出 (MIMO) 天线，该天线工作在 2.45 GHz 工业科学和医疗 (ISM) 频段。8字形辐射器，带L形接地槽，使天线尺寸小型化。在天线下方添加了一个电介质反射器，以减少向身体组织的背辐射。在三层等效组织模型上分析在体性能。天线在靠近身体组织并使用介电反射器工作时显示出 -40 dB 的反射系数、58% 的效率和 6.7 dBi 的方向性。单向辐射模式和低比吸收率使天线适合在体通信。此外，分集性能是根据包络相关系数 (ECC) 和分集增益 (DG) 来衡量的。在 2.45 GHz 时，ECC 的值为 0.045，DG 为 9.7 dB。通过沿 x 轴弯曲结构来检查天线的稳健性。所提出结构的性能使其成为身体通信的合适候选者。