Twelve-Element MIMO Wideband Antenna Array Operating at 3.3 GHz for 5G Smartphone Applications

This work presents a 12-element multiple-input–multiple-output (MIMO) wideband antenna array for mobile smartphones. The antenna element is mainly composed of two parts, greatly improving the antenna array bandwidth: one is a meandering, looped radiating element and the other is a U-shaped slot. For the antenna element design, the meandering, looped radiating element measures 12.95 × 6 mm2, while the U-shaped slot has a size of 15 × 3 mm2. Meanwhile, the reflection coefficient indicates that the designed antenna array operates at 3.3 GHz with a bandwidth of 500 MHz; the transmission coefficient shows that the isolation between the antenna elements is better than 12 dB. In addition, more antenna array performances are presented, including nearly omnidirectional radiation characteristics, antenna efficiency ranging from approximately 17 to 60%, envelope correlation coefficients (ECCs) below 0.065, and diversity gain (DG) values of the MIMO antenna system close to 10 dB. The measurement results are highly consistent with the simulation results of the designed wideband antenna array, indicating its great potential for future practical engineering applications.