## 5 Conclusions  
A UWB-MIMO antenna based on MTM was assembled for research application within 5G, X-band, Ka and Ku bands, and satellite communications. There are four antenna components were positioned at each corner of a board, respectively, for the communication linkages. The MAVA is used in the proposed metamaterial-integrated MIMO antenna to achieve dual-polarization and polarization diversity. The antenna was developed on a denim substrate with \(\varepsilon_{r}\) = 1.4, tan = 0.02 and h = 0.5 mm thickness. The suggested antenna's dual-polarization capability is designed to decrease the significant attenuation that happens in 5G communication networks (particularly at higher frequencies) and to achieve large data speeds. Moreover, orthogonal polarization between each pair of antenna ports is used to achieve excellent isolation between antenna ports. At 3.7-3.85 GHz and 5-40 GHz, the proposed UWB-MIMO antenna has an impedance matching bandwidth. Specifically, the antenna is purposely loaded with staircase meander line, then coupled with the MTM structure in order to reduce mutual coupling effects, thus, increase its gain and efficiency. The studied UWB-MIMO antenna has a high isolation of more than 22 dB, an ECC of less than 0.01, and acceptable diversity gain. Subsequently, the Gustav voxel arm and chest were evaluated, and the SAR values at the whole working BW were thoroughly analyzed in the simulation.  
In conclusion, the designed UWB-MIMO antenna gained higher isolation, efficiency, and gain; smaller footprint and size, easier implementation, and lower cross-polarization. It demonstrates that it has strongly fulfills requirements to opt functioning whether for 5G, LTE, X-band, Ka and Ku bands, or/and satellite communications. Actually, there are several problems may occur during fabricating 5G devices and antennas processes utilizing normal non-flexible board, particularly, for high frequency and mm-wave band antennas especially when incorporating them with radio frequency circuits in wearable devices and systems. We offered a compact and flexible UWB-MIMO antenna, which is suitably wearable for ultra-thin 5G mobile devices without significantly compromising the antenna's functionality. It is open for additional functions to be incorporated into customizable designs imaginable along the future direction in its technological advancement specifically utilizing 5G and satellite communication applications.  
Figure 31: The simulated and measured reflection and transmission coefficient results on (**a**) arm and (**b**) chest for single element MIMO.  
**Author Contributions:** [PERSON] led, supervised, and evaluated the entire project: edited the write ups, designed, and simulated together with [PERSON] who performed the experimental measurement and wrote the required programs, and a complete initial draft of the paper. [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and M.A.I. evaluated and edited the paper. All authors have read and agreed to the published version of the manuscript.  
**Funding:** The project was funded by Najran University, research grant number NU//-/SERC/10/656.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Acknowledgments:** The authors would like to express their Gratitude to the Ministry of Education and the deanship of scientific research--Najran University--Kingdom of Saudi Arabia for their financial and technical support under code number (NU//-/SERC/10/656).  
**Conflicts of Interest:** The authors declare no conflict of interest.