Wideband Diversity Mimo Antenna Design With Hexagonal Slots for 5g Smart Mobile Terminals

Abstract

In this paper, we propose a wideband polarization diversity multiple-input multiple-output (MIMO) antenna array for 5G smart mobile devices. The proposed MIMO antenna array consists of 8-ports dual-polarized L-shaped lines that highly excite radiating slots, where the elements are placed at four-corners of a compact mobile unit of size 75 × 150 mm 2 . The uniqueness of the proposed MIMO antenna structure comes from the deployment of octagon-shaped resonant slots within the metallic ground plane, i.e., the octagonal-slots are etched from the bottom (ground) layer of the main mobile board. Due to the unique slots in the ground plane, wideband impedance has been achieved (3.38-3.8 GHz at −6-dB threshold). The proposed smart phone 8 × 8 diversity MIMO antenna is designed to support the spectrum of commercial sub-6 GHz 5G communications and cover the frequency range of around 3.5 GHz band with high decoupling between antenna ports. The proposed array is designed, numerically simulated, fabricated, and tested. Good agreement between simulated and measured results was achieved. The MIMO antenna has a satisfactory far-field performance along with very low envelope correlation coefficient (ECC) < 0.055, high diversity of more than 9.95, and very low specific absorption rate (< 1 W/kg for a 10-g human tissue).

Compact Sub 6 GHz Slot Multiantenna System for 5G Laptops

“…As a result, the characteristics of many antennas installed in mobile communications devices are evolving into smaller sizes and lower profiles. Several multiple input, multiple output (MIMO) multiantenna systems for mobile devices and 5G applications [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ] have been continuously proposed with the rapid spread of 5G MIMO technology, which also include the 5G MIMO multiantenna systems for mobile phones. In these systems, multiple antennas are configured at appropriate distances to maintain a certain degree of isolation.…”

“…In these systems, multiple antennas are configured at appropriate distances to maintain a certain degree of isolation. The spacing between the antennas in them is about 10–30 mm [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. Some designs incorporate isolation elements to optimize the degree of isolation between antennas [ 14 , 15 ].…”

“…The MIMO antenna systems use slot structures [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ], which can be seamlessly integrated with metallic surroundings and are particularly suitable for devices with metal frames or back covers. Notably, refs.…”

“…Notably, refs. [ 10 , 11 , 12 , 13 ] belong to the state-of-the-art literature within the past year. In [ 10 ], the authors proposed eight identical small inverted F-shaped folded slots etched onto a metal frame as a highly isolated MIMO antenna.…”

“…The decoupling process involves simply etching slot lines based on the cancellation of the common and differential modes. In [ 13 ], the authors proposed a MIMO antenna structure that comes from the deployment of octagon-shaped resonant slots within the metallic ground plane. Due to the unique closed slot in the ground plane, wideband impedance was achieved.…”