Ultra-Wideband MIMO Antenna System With High Element-Isolation for 5G Smartphone Application

• Main Authors: Xiao-Ting Yuan, Wei He, Kai-Dong Hong, Chong-Zhi Han, Zhe Chen, Tao Yuan
• Format: Article
• Language: English
• Published: IEEE 2020-01-01
• Series: IEEE Access
• Subjects: 5G communication; sub-6 GHz; ultra-wideband; high isolation; metal frame
• Online Access: https://ieeexplore.ieee.org/document/9042829/

In this paper, we presented an ultra-wideband multiple-input multiple-output (MIMO) antenna system with high element-isolation for the application in 5G metal-frame smartphones. We proposed T-shaped and C-shaped slots on the metal frame generating four resonances to enhance the bandwidth. What's more, we introduce modified H-shaped slots between each antenna-element to improve the element-isolation of MIMO antenna system. As a result, the MIMO antenna system has a wide bandwidth of 58% ranging from 3.3 to 6 GHz and the element-isolation is over 18 dB crossing the effective frequency band. Thanks to the decent element-isolation, the envelope correlation coefficient (ECC) between each antenna-element is below 0.05 providing a reliable anti-interference for the MIMO antenna system. In addition, the measured radiation efficiencies of the MIMO antenna system are higher than 40%. At last, we analyze the effects caused by user's hands and head to guarantee the robustness of the MIMO antenna system in practical applications.