Wideband Monopole Eight-Element MIMO Antenna for 5G Mobile Terminal

Abstract

An eight-element wideband multiple-input multiple-output (MIMO) antenna for the fifth-generation (5G) mobile terminal is proposed. The antenna elements are placed along both long side edges of the mobile terminal with a profile of 6 mm. The proposed monopole-inspired antenna element shows a good impedance match, isolation, and diversity parameter across a very wide bandwidth of 78 % (3.2-7.3 GHz), and it can cover the 5G NR n77/n78/n79/n96, LTE 46, and WLAN 5 GHz bands. The result shows that the MIMO antenna can offer inter-element isolation better than 12 dB, envelope correlation coefficient (ECC) below 0.069, and a peak channel capacity of 42.7 bps/Hz across the desired 5G bands. The specific absorption rate (SAR) analysis of the proposed MIMO antenna with a human head has exhibited SAR levels (0.41 W/Kg and 0.33 W/Kg at two resonating frequencies 3.9 GHz and 5.8 GHz, respectively) much lower than the Federal Communications Commission (FCC) permissible limit (1.6 W/Kg over 1 gram tissue).