8 × 8 element MIMO antenna for unmanned aerial vehicles, V2X and 5G applications

In this study, a compact (30 × 30 × 0.508 mm³) 8-port MIMO antenna for unmanned aerial vehicles (UAV), vehicle-to-everything (V2X) and 5G applications is designed, developed, tested and discussed. After a systematic study, an optimal single element of the proposed antenna is chosen from four steps (Step 1, Step 2, Step 3, Step 4). The geometry of the proposed antenna comprises eight circular radiating elements on the top plane of the substrate in which pentagon structure is etched out from each element to resonate it at 5.5 GHz. Stepped rectangular structure is removed from the ground plane underneath of each radiating elements. A dielectric substrate (RT/Duorid (5870 tm)) is used to fabricate the proposed antenna design with following specification: ε_r = 2.33, h = 0.508 mm, loss tangent (tan δ = 0.0012). A unique structure of the proposed antenna geometry exhibits -10 dB wideband bandwidth of 1.32 GHz (5-6.32 GHz) and high isolation (> 30 dB) in entire band. A peak gain of 6.5 dB and 92% radiation efficiency have been achieved. Moreover, good degree of MIMO characteristics such as envelope correlation coefficient (ECC) (< 0.001), diversity gain (DG) (> 9.87 dB), channel capacity loss (CCL) (< 0.04 bits/s/Hz), channel capacity (37.6 bits/s/Hz) and mean effective gain (MEG) (-12 dB < MEG < -3 dB) have also been obtained. The antenna design was simulated through HFSS and fabricated & tested for further validation of results. Simulated results were found in strong concordance of experimental results.