Eight-element self-decoupled MIMO antenna design for 5G smartphones

A self-decoupled antenna element working at half- wavelength mode is proposed and implied into an eight-element multiple-input-multiple-output (MIMO) antenna array for the fifth-generation (5G) smartphones applications. Particularly, self- decoupled is conveyed by the feature of balanced antenna, which is composed of an open slot (0.197 lambda(0) x 0.035 lambda(0) at 3.5 GHz) excited by a two-arm feedline located on the horizontal ground board and a half-wavelength dipole-type mode is formed. A week ground current effect and high-isolation level are achieved with no additional decoupling stub. Besides, the location of the element is thoroughly considered to achieve a desirable decoupling effect. In the desired 3.5 GHz band (3.4-3.6 GHz), isolation of more than 18.5 dB and total efficiency of more than 65% are obtained. The proposed MIMO antenna was simulated and fabricated. The corresponding performances were claimed by simulated results and measured ones, a good uniformity between the two was obtained.