###### Abstract  
The article represents the design of two port-based printed MIMO antenna structures that have the advantages of low profile, simple structure, good isolation, peak gain, directive gain, and reflection coefficient. The performance characteristics are observed for the four design structures by cropping the patch region, loading the slits near the hexagonal-shaped patch, and adding and removing the slots in the ground area. The antenna provides a least reflection coefficient of \(-\)39.44 dB, a maximum electric field of patch region of 33.3 V/cm, a total gain of 5.23 dB, and good values of total active reflection coefficient and diversity gain. The proposed design provides nine bands' response, a peak bandwidth of 2.54 GHz, and a peak bandwidth of 26.127 dB. The four proposed structures are fabricated using a low-profile material to support mass production. The comparison among simulated and fabricated structures is included to check the authenticity of the work. The performance assessment of the proposed design with other published articles is carried out for the performance observation. The suggested technique is analyzed over the wideband of frequency region 1 GHz to 14 GHz. The multiple band responses make the proposed work suitable for wireless applications in S/C/X/Ka bands. MIMO antenna; complementary split ring resonator; metamaterial; DG; gain; patch antenna 2023141232  
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[PERSON], [PERSON], S.  
and efficiency of mm-wave 5G antennas and their bandwidth are expected to be high. The benefits of printed antennas, such as their flat construction and design simplicity, have led to significant studies in mm-wave wireless communications. In addition, the metamaterial property helps to achieve better antenna performance. For MIMO technology to function, it is essential that the antenna components used by the transmitter and receiver be independent of one another. In order to measure the performance of an antenna array in MIMO systems, numerous metrics have been proposed in [7]. The miniaturization of the MIMO structure has been shown to reduce the isolation between antenna components in [8]. The decoupling technology in MIMO using 3D metamaterial structures improves antenna isolation. In [9], the reduction in mutual coupling using defective isolation is presented. Article [10] suggests using an isolated radial resonator for enhancing isolation among two elements of a patch in the MIMO antenna. A novel technique to reduce interference amongst the many antennas used in 5G's proposed MIMO design is suggested in [11]. The deployment of 5G networks relies on the development of an effective antenna structure for 5G networks. The great spectral efficiency and low power consumption of massive MIMO have made it a frontrunner for the 5G network. In [12], the antenna represents the lower isolation, and bandwidth is important in MIMO antenna design. Article [13] shows a broad bandwidth and high gain as being the most significant. The dipole antenna equipped with a metamaterial array provides a high gain in the end-fire direction. The article demonstrates a change in the center frequency due to shared ground and very poor isolation between the antenna's components. Article [14] represents a greater level of interfering noise hinders signal transmission due to \(-10\) dB isolation between antenna band notch characteristics for two-port MIMO, and an antenna is proposed in [15], with a lower gain of 2 dBi. Article [16] presents a method for achieving a wider bandwidth of 2.1 to 11 GHz. Two quasi-self-complimentary MIMO antennas have been suggested in [17] to attain an ultra-wide bandwidth. In addition to being small, the antenna provides a significant gain. While the envelope correlation coefficient (ECC) and isolation are lower in quasi structure, the arrangement of the structure in a better way enables less isolation and ECC. Diversity constraints are not explored for the suggested quasi-shaped antenna.