Ud Din Iftikhar, Alibakhshikenari Mohammad, Virdee Bal S, Jayanthi Renu Karthick Rajaguru, Ullah Sadiq, Khan Salahuddin, See Chan Hwang, Golunski Lukasz, Koziel Slawomir
Telecommunication Engineering Department, University of Engineering and Technology, Mardan 23200, Pakistan.
Department of Signal Theory and Communications, Universidad Carlos III de Madrid, 28911 Leganés, Madrid, Spain.
Sensors (Basel). 2023 Aug 7;23(15):7009. doi: 10.3390/s23157009.
In this paper, a radiating element consisting of a modified circular patch is proposed for MIMO arrays for 5G millimeter-wave applications. The radiating elements in the proposed 2 × 2 MIMO antenna array are orthogonally configured relative to each other to mitigate mutual coupling that would otherwise degrade the performance of the MIMO system. The MIMO array was fabricated on Rogers RT/Duroid high-frequency substrate with a dielectric constant of 2.2, a thickness of 0.8 mm, and a loss tangent of 0.0009. The individual antenna in the array has a measured impedance bandwidth of 1.6 GHz from 27.25 to 28.85 GHz for S ≤ -10 dB, and the MIMO array has a gain of 7.2 dBi at 28 GHz with inter radiator isolation greater than 26 dB. The gain of the MIMO array was increased by introducing frequency-selective surface (FSS) consisting of 7 × 7 array of unit cells comprising rectangular C-shaped resonators, with one embedded inside the other with a central crisscross slotted patch. With the FSS, the gain of the MIMO array increased to 8.6 dBi at 28 GHz. The radiation from the array is directional and perpendicular to the plain of the MIMO array. Owing to the low coupling between the radiating elements in the MIMO array, its Envelope Correlation Coefficient (ECC) is less than 0.002, and its diversity gain (DG) is better than 9.99 dB in the 5G operating band centered at 28 GHz between 26.5 GHz and 29.5 GHz.
本文提出了一种由改进型圆形贴片组成的辐射单元，用于5G毫米波应用的MIMO阵列。所提出的2×2 MIMO天线阵列中的辐射单元相互正交配置，以减轻相互耦合，否则会降低MIMO系统的性能。MIMO阵列是在罗杰斯RT/Duroid高频基板上制作的，该基板的介电常数为2.2，厚度为0.8毫米，损耗角正切为0.0009。阵列中的单个天线在S≤-10 dB时，测得的阻抗带宽为1.6 GHz，频率范围为27.25至28.85 GHz，MIMO阵列在28 GHz时的增益为7.2 dBi，辐射器间隔离大于26 dB。通过引入由7×7单元阵列组成的频率选择表面（FSS），MIMO阵列的增益得到了提高，该单元阵列由矩形C形谐振器组成，其中一个嵌套在另一个内部，中间有一个十字交叉开槽贴片。使用FSS后，MIMO阵列在28 GHz时的增益提高到了8.6 dBi。阵列的辐射是定向的，且垂直于MIMO阵列的平面。由于MIMO阵列中辐射单元之间的耦合较低，其包络相关系数（ECC）小于0.002，在以28 GHz为中心、26.5 GHz至29.5 GHz的5G工作频段内，其分集增益（DG）优于9.99 dB。
