Dual-Band MIMO System Based on Metal Frame for 5G Applications

In this paper, a metal-frame-based dual-band 4-antenna multi-input and multi-output (MIMO) system operating at both 3.3-3.6 GHz and 4.8-5.0 GHz bands for the fifth-generation (5G) mobile applications is proposed. Each antenna element consists of a rectangular feeding branch, an L-shaped slot and an L-shaped coupling branch. The slot and coupling branch are excited by the feeding branch to generate the low (3.45 GHz) and high (4.8 GHz) resonant frequencies. In particular, the L-shaped slot is set on the metal frame of the mobile handsets, which makes the antenna element and metal housing well integrated. A simplified antenna prototype is fabricated and measured. The simulation and measurement results, such as S-parameter, efficiency, envelope correlation coefficient (ECC) and 3D radiation pattern are presented. And the simulation and measurement results can have good agreement.