Designing a Millimeter-Wave MIMO Antenna for Sustainable Development in 5G Technology

Due to low latency, high-speed data transmission, and the ability to connect millions of devices, 5G networks excel over 4G technologies. Within this context, a MIMO antenna functioning in the millimeter-wave frequency band is investigated. Initially, a 38 GHz single antenna operating within the millimeter-wave spectrum, featuring dimensions of 2.02 × 3.12 mm2 and a thickness of 0.8 mm, was designed using an RT/duroid 5880LZ substrate with the HFSS EM software. Subsequently, it was extended to a four-element millimeter-wave MIMO antenna array on a ground plane with dimensions of 20 mm × 20 mm by duplicating the single millimeter-wave antenna at a λ/4 distance. To enhance the effectiveness and compactness of the millimeter-wave MIMO antenna, the size of the four antenna elements was modified from 2.02 mm × 3.12 mm to 1.8 mm × 2.4 mm. This was accomplished by systematically reducing the length and width by 1 mm increments. Additionally, a diagonal square slot was introduced into the ground plane, forming a defected ground structure (DSSDGS) and it was designated as modified millimeter-wave MIMO antenna (MMWMA). The designed antenna resonated at dual-band frequency points, specifically 28 GHz and 38 GHz, with return loss values of −13.9 dB and −15.96 dB, along with a satisfactory bandwidth of 3.8 GHz and 3.5 GHz, respectively. The data rates (DR) are found to be 76Gbps at 28 GHz and 71Gbps at 38 GHz, as well as the mutual coupling coefficients (MCC) of the antenna are low at −18.67 dB and −23.1 dB, with envelope correlation coefficients of 0 and a diversity gain (DG) of 10 dB, respectively. These findings suggest that the MIMO antenna structure is suitable for 5G technology.