Isolation enhancement of a four-element broadband MIMO antenna for 5G mobile handsets

A compact broadband four-element MIMO antenna for mobile handsets is presented. The proposed antenna operates over a broad frequency band including LTE2300/2500, WLAN/WiMAX, LTE42/43/46, and lower UWB bands. It consists of four identical planar radiation elements, which are distributed at four corners of the dielectric substrate. The radiator occupies a tiny size of 15x12 mm2 and is suitable for the popular ultra-thin smartphone applications. By using T-shaped defected ground structure (DGS), a good isolation performance over 12 dB across the whole operating bands has been achieved. The S-parameters and radiation patterns are simulated and verified through measurements. In addition, the total efficiency, peak gain, and ECCs are also simulated and studied by CST software.