This paper proposes a four-port, four-element multi-band Multiple-Input Multiple-Output (MIMO) antenna array that resonates at 2.4 GHz, 2.9 GHz, and/or 5.8 GHz frequency bands for WLAN applications. A Complementary Split Ring Resonator (CSRR) was designed on the ground plane of the FR4 substrate with a rectangular patch antenna on the top plane for antenna size miniaturization, bandwidth improvement, compactness, and isolation enhancement. At first, the presence of the CSRR on the conventional antenna creates additional frequency bands and reduces the frequency of the conventional patch antenna from 24.2 GHz to 5.8 GHz. Even though the CSRR as radiating elements are closer to each other at λ/4 in the MIMO design, minimum isolation is achieved by limiting the unnecessary surface current flow that exists between the elements of the antenna. Consequently, an orthogonal method of the antenna element is adopted for the four-port MIMO antenna system with high port-to-port measured isolation of less than −19 dB, −18 dB, and –22 dB for 2.4 GHz, 2.9 GHz, and 5.8 GHz frequency bands respectively. Antenna size reduction of 96.87%, 95.41%, and 81.10% and gain of 3.94 dBi, 3.80 dBi, and 4.08 dBi were achieved for the miniaturized multi-band antenna operating at 2.4 GHz, 2.9 GHz, and 5.8 GHz frequency bands, respectively. The results also provided overall good diversity performances with the ECC < 0.01, DG > 9.98, MEG < 3 dB, and TARC in all of the proposed multi-band MIMO antenna systems at respective frequencies. The reflection & transmission coefficients, surface currents, radiation patterns, total efficiency, and diversity parameters are presented and discussed. Moreover, the proposed integration of CSRR with the antenna for MIMO antenna arrays has the advantage of multi-band operation, size reduction, isolation enhancement, good diversity, and high gain performances. With this, it is possible to conclude that the proposed metamaterial multi-band MIMO antenna is the right candidate for WLAN applications.

本文提出了一种四端口，四元素多频带多输入多输出（MIMO）天线阵列，该天线阵列在WLAN应用中的2.4 GHz，2.9 GHz和/或5.8 GHz频段产生谐振。在FR4基板的接地平面上设计了一个互补的分体式环形谐振器（CSRR），在顶部平面上有一个矩形贴片天线，用于天线尺寸的小型化，带宽的改善，紧凑性和隔离度的提高。首先，常规天线上CSRR的存在会产生额外的频带，并将常规贴片天线的频率从24.2 GHz降低到5.8 GHz。即使在MIMO设计中，作为辐射元件的CSRR在λ/ 4处彼此更靠近，通过限制天线元件之间存在的不必要的表面电流，也可以实现最小隔离。因此，对于四端口MIMO天线系统，采用了正交的天线元件方法，对于2.4 GHz，2.9 GHz，高端口到端口实测隔离度低于−19 dB，−18 dB和–22 dB，和5.8 GHz频段。对于工作在2.4 GHz，2.9 GHz和5的小型化多频带天线，天线尺寸减小了96.87％，95.41％和81.10％，增益分别为3.94 dBi，3.80 dBi和4.08 dBi。分别为8 GHz频带。结果还提供了所有拟议的多频带MIMO天线系统在各个频率上的ECC <0.01，DG> 9.98，MEG <3 dB和TARC的总体良好分集性能。提出并讨论了反射和透射系数，表面电流，辐射图，总效率和分集参数。而且，所提出的将CSRR与MIMO天线阵列的天线集成具有多频带操作，尺寸减小，隔离增强，良好的分集和高增益性能的优点。这样，可以得出结论，建议的超材料多频带MIMO天线是WLAN应用的正确候选者。在所有拟议的多频带MIMO天线系统中，在各个频率上的频率为01，DG> 9.98，MEG <3 dB和TARC。提出并讨论了反射和透射系数，表面电流，辐射图，总效率和分集参数。而且，所提出的将CSRR与用于MIMO天线阵列的天线集成具有以下优点：多频带操作，尺寸减小，隔离增强，良好的分集和高增益性能。这样，可以得出结论，建议的超材料多频带MIMO天线是WLAN应用的正确候选者。在所有拟议的多频带MIMO天线系统中，在各个频率上的频率为01，DG> 9.98，MEG <3 dB和TARC。提出并讨论了反射和透射系数，表面电流，辐射图，总效率和分集参数。而且，所提出的将CSRR与MIMO天线阵列的天线集成具有多频带操作，尺寸减小，隔离增强，良好的分集和高增益性能的优点。这样，可以得出结论，建议的超材料多频带MIMO天线是WLAN应用的正确候选者。提出并讨论了分集参数。而且，所提出的将CSRR与用于MIMO天线阵列的天线集成具有以下优点：多频带操作，尺寸减小，隔离增强，良好的分集和高增益性能。这样，可以得出结论，建议的超材料多频带MIMO天线是WLAN应用的正确候选者。提出并讨论了分集参数。而且，所提出的将CSRR与用于MIMO天线阵列的天线集成具有以下优点：多频带操作，尺寸减小，隔离增强，良好的分集和高增益性能。这样，可以得出结论，建议的超材料多频带MIMO天线是WLAN应用的正确候选者。