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

Abstract

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 elementisolation 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 antennaelement 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. INDEX TERMS 5G communication, sub-6 GHz, ultra-wideband, high isolation, metal frame.

Multiantennas conjoined with metal frame and integrated into 8 × 8 m ultiple‐input and m ultiple‐output array for fifth generation smartphone applications

“…The metal frame has been fully configured. 25,26 The open-slot method produced multiple discontinuous sections. The 8 × 8 MIMO configuration created eight groups of independent metal frame surfaces.…”

“…The full‐metal frame problem 24 was investigated, but the MIMO scenario was not configured. The metal frame has been fully configured 25,26 . The open‐slot method produced multiple discontinuous sections.…”

“…A design of 5G mobile phones with primary and secondary antennas and an 8-antenna array MIMO configuration has not been fully developed, although several studies have worked on this topic. [21][22][23][24][25][26] This study aimed to develop a complete solution in addition to covering the full band of long-term evolution (LTE) applications. A design for a four-port feed design with different antennas and MIMO configurations in mobile phones is proposed.…”

“…Some techniques for generating such resonance modes are dual‐loop, 17 inductive and capacitive monopoles, 18,19 and close slots methods 20 as well as a novel design method using gap‐coupled loops. A design of 5G mobile phones with primary and secondary antennas and an 8‐antenna array MIMO configuration has not been fully developed, although several studies have worked on this topic 21‐26 …”

Hybrid Antenna Array for 4g/5g Smartphone Applications

“…It is well known that most mobile phones with an internal dual-antenna system are designed to cover the LTE/WWAN operation [9][10][11][12], which only takes into consideration of 4G frequency bands. In order to satisfy future 5G applications, MIMO antennas for 5G smartphone applications have been discussed in [13][14][15][16][17][18]. These MIMO antennas could cover the 5G (3300-3600 MHz); however, the bandwidth is too narrow to completely cover the new generation of mobile communication, which is 4800-5000 MHz.…”