aspg-20-1571-1791307686 20261006172806 American Scientific Publishing Group admin@americaspg.com American Scientific Publishing Group International Journal of Wireless and Ad Hoc Communication IJWAC 2692-4056 2022 5 1 Basma M. Yousef Delta Higher Institute for Engineering and Technology, Talkha , 3511, Mansoura, Egypt Reham Arnous Delta Higher Institute for Engineering and Technology, Talkha , 3511, Mansoura, Egypt A novel design of metamaterial structure has been developed to reduce the mutual coupling between two microstrip patch antennas. A split rectangular structure loaded between the two microstrip patches is the method used to decrease coupling. The proposed antenna is designed to operate at a frequency of 28 GHz. This construction is suited for use with mm-wave, 5G antenna systems, and mobile applications. The connection between antennas is significantly improved. The maximum isolation achieved is 29.5 dB by etching the split rectangular structure on the ground of the proposed antenna and on a floated ground between the two patches. The distance between the two elements of the antenna, from edge to edge, is 0.4λ. The design is achieved with CST Studio software. 2022 65 70 1571 https://creativecommons.org/licenses/by/4.0/ 10.54216/IJWAC.050106 https://americaspg.com/journal/20/article/1571 https://americaspg.com/storage/51677030591.pdf