Here, an ultra‐compact Multi‐Input‐Multi‐Output (MIMO) antenna system is presented for Wireless Local Area Network (WLAN) applications. The proposed antenna compactness approach is based on using Cylindrical‐Dielectric‐Resonator‐Antenna (CDRA) symmetry with the help of image theory to achieve the best size reduction of the resonators and maintain the resonance frequency of the original CDRA. The electric/magnetic walls approach is utilized to miniaturize the size by exploring the symmetry and antisymmetry of the resonant mode. First, a CDRA for MIMO system is designed and tested in terms of return loss and radiation efficiency. Then, two configurations of MIMO‐Antennas (two and four ports) are examined by using the same substrate size. The 2‐port‐MIMO antenna is built from two half‐CDRs (HCDRs) facing each other. Similarly, four‐quarter‐CDRs (QCDRs) are created to form a 4‐port MIMO antenna system. As a result, a 75% size reduction is achieved (size of 30 × 30 × 7.62 mm³). The measured impedance bandwidth for the 4‐port MIMO antenna is 5.4% (5.4‐5.7 GHz), with more than 15 dB isolation levels. Proper levels of Envelope Correlation Coefficients (ECCs) are also achieved (1 × 10⁻²‐4 × 10⁻²), with a channel capacity loss (CCL) of 0.04 bits/S/Hz. The proposed MIMO antennas are suitable for compact wireless communication systems.

中文翻译：

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适用于多输入多输出标准的超紧凑型4端口DR天线

在此，提出了一种用于无线局域网（WLAN）应用的超紧凑型多输入多输出（MIMO）天线系统。拟议的天线紧凑方法是基于圆柱介电谐振器天线（CDRA）对称性，并借助图像理论来实现谐振器的最佳尺寸减小，并保持原始CDRA的谐振频率。通过探索共振模式的对称性和反对称性，利用电/磁壁方法将尺寸最小化。首先，针对回波损耗和辐射效率设计并测试了用于MIMO系统的CDRA。然后，使用相同的基板尺寸检查MIMO-天线的两种配置（两个和四个端口）。2端口MIMO天线由彼此相对的两个半CDR（HCDR）构成。同样，创建四分之四的CDR（QCDR）以形成4端口MIMO天线系统。结果，尺寸减小了75％（尺寸为30×30×7.62 mm³）。4端口MIMO天线的测量阻抗带宽为5.4％（5.4-5.7 GHz），隔离级别超过15 dB。还可以实现适当水平的包络相关系数（ECC）（1×10 ^-2 -4×10 ^-2），通道容量损耗（CCL）为0.04位/ S / Hz。所提出的MIMO天线适用于紧凑型无线通信系统。