Fractal Loaded, Novel, and Compact Two- and Eight-Element High Diversity MIMO Antenna for 5G Sub-6 GHz (N77/N78 and N79) and WLAN Applications, Verified with TCM Analysis

A novel compact fractal loaded two- and eight-element multiple input multiple output (MIMO) with strong diversity is designed for 5G Sub 6 GHz and WLAN applications. The suggested antenna is designed and manufactured on inexpensive FR4 dielectric material with small size of 72 mm x 72 mm x 1.6 mm (0.792 lambda x 0.792 lambda x 0.0176 lambda, where lambda is calculated at a lower operating frequency). The proposed layout features a partially grounded, protruding T-shaped stub on the underside of the substrate and a set of fractally loaded circular patch antenna elements on the top. Four triangular slots on the substrate and a T-shaped stub on the ground are employed to produce good isolation over the intended bands. The proposed antenna has a frequency range of (3.3-6.0) GHz, making it compatible with the 5G sub-6 GHz bands and the WLAN band thanks to its high isolation of above 15 dB and good impedance matching characteristics. Good agreement is observed between the antenna results and the theory of characteristic mode analysis approach. The designed antenna is well suited for 5G sub-6 GHz and WLAN communication applications due to its low ECC (0.005), total active reflection coefficient (TARC) (-10 dB), mean effective gain (MEG) (-3 dB), and diversity gain (DG) (-10 dB), channel capacity losses (CCL) (0.05), peak gain (>2.5 dBi), radiation efficiency (>95%), and stable boresight radiation patterns.