基于 CSRR 去耦合结构的八单元紧凑型宽带 MIMO 天线

Compact eight-element wideband MIMO antenna based on CSRR- decoupling technique

摘要

针对 5G 无线通信系统中多输入多输出（MIMO）天线单元间互耦效应导致系统性能下降的问题，提出了一种面向 Wi-Fi 应用场景的改进型并联组合 CSRR 去耦合结构的八单元 MIMO 天线。该天线基于互补开口谐振环（CSRR）去耦技术，实现了紧凑型结构、宽频带特性与优异隔离性能的协同优化。实测结果表明：天线 −10 dB 阻抗带宽为 19%，在 5.50～6.66 GHz 工作频段内，端口 1 与端口 2、端口 8 之间的隔离度分别优于 16.7 dB 和 13.7 dB；天线系统辐射效率为 50%～86%，峰值增益为 3.28 dBi，包络相关系数低于 0.1，分集增益优于 9.91 dB，各项指标均满足 5G 移动终端应用需求。通过分析 CSRR 几何构型与空间排布对系统性能的影响，揭示了并联组合 CSRR 结构通过谐振阻带效应、表面波抑制和近场电场重构三重协同机制，显著提升了天线单元间的隔离度。研究结果为高性能 MIMO 天线的去耦设计提供了理论依据和技术路径。

Abstract

Abstract:To address the degradation of system performance caused by mutual coupling among antenna elements in multi-input multi-output (MIMO) systems for 5G wireless communications, an eight-element MIMO antenna based improved parallel-combined CSRR decoupling structure design tailored for WiFi applications is proposed. The mutual coupling effect among the MIMO antenna units in a 5G wireless communication system leads to a degradation of the system performance. To address this issue, an improved parallel combined CSRR (complementary split-ring resonator) decoupling structure for an eight-element MIMO antenna design tailored for WiFi application scenarios is proposed. The antenna employs a decoupling technique based on CSRRs, achieving an optimal balance among compact structure, wideband operation, and high isolation performance. Experimental results demonstrate that the antenna achieves a −10 dB impedance bandwidth of 19%, with isolation levels of S ₂₁ > 16.7 dB and S ₈₁ > 13.7 dB within the 5.50 GHz to 6.66 GHz operating band; and the antenna system achieves a radiation efficiency of 50% to 86%, a peak gain of 3.28 dBi, an envelope correlation coefficient (ECC) below 0.1, and a diversity gain exceeding 9.91 dB, meeting the requirements for 5G mobile terminal applications. By analyzing the impact of CSRR geometric configurations and spatial arrangements on system performance, this study reveals that the parallel-combined of CSRR structure enhances the isolation through a triple synergistic mechanism comprising resonance band-stop effect, suppression of surface waves, and near-field electric field reconstruction. The research findings provide theoretical insights and technical pathways for the decoupling design of high-performance MIMO antennas.

关键词

多输入多输出天线 / Wi-Fi / 互补开口谐振环 / 宽带 / 隔离

Key words

multiple input multiple output antenna / Wi-Fi / complementary split-ring resonator / wide bandwidth / isolation

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基金资助

甘肃省科技计划项目(23JRRA1704)

甘肃省重点研发计划(22YF7GE202)

甘肃省科技计划(18JR3RA104)