Investigation on Simulation-Based Octagonal Ring MIMO Antenna for 5G Applications

The fifth-generation (5G) communication shows the progress of the entire cellular network architecture. Indonesia has just launched the first 5G network on May 21, 2021, as a tangible manifestation of the leading digital telecommunication. The 5G band allocation used for the first deployment is in the medium frequency band (2-6 GHz). In this paper, the 5G high-frequency band (beyond 6 GHz) is used to design a MIMO antenna for future deployment. The MIMO antenna is designed for 5G applications working at a frequency of 38 GHz. This allocated frequency was also recommended by the Federal Communications Commission (FCC). The antenna was designed by using a patch in the form of an octagon ring with microstrip line feeding. MIMO technique is used to increase system capacity with a gain value above 10 dBi. Antenna MIMO is designed using a material substrate RT Duroid 5880 with $\varepsilon r$ = 2.2, thickness (h) = 0.254 mm, and tan $\delta = 0.0009$. From the simulation, the S11 reached -29.5 dB, a gain of 13.44 dBi, mutual coupling below -20 dB, and bandwidth of 14.002 GHz (31.008 GHz to 45.01 GHz).