A Compact Dual-Band MIMO Antenna for Sub-6 GHz 5G Terminals

Abstract

In this paper, a dual-band multiple-input-multiple-output (MIMO) antenna is proposed for fifth-generation (5G) wireless communication terminals. The measured -10 dB impedance bandwidths of 380 MHz (3.34–3.72 GHz) and 560 MHz (4.57–5.13 GHz) can cover the 3.4–3.6 GHz and 4.8–5 GHz 5G bands. The single antenna element of this proposed MIMO is composed of an F-shaped feed strip and an inverted L-shaped radiation strip. A defected ground structure is employed to obtain a good isolation performance, whereby the measured isolation between the antenna elements is observed to be larger than 23 dB. The measured total radiation efficiencies at 3.5 GHz and 4.9 GHz are 76.65% and 71.93%, respectively. Besides, the calculated envelope correlation coefficients (ECC) are less than 0.00125 and 0.01164 at the low-frequency and high-frequency bands, respectively. Furthermore, the specific absorption ratio (SAR) analysis of the antenna verifies that it qualifies for 5G terminals.

Compact Dual-Band On-Body Near Field Antenna With Reflector for Measuring Deep Core Temperature

“…Microstrip patch antenna is widely used at various wireless communications field [31][32][33][34][35][36]. However, it has a narrow bandwidth, which renders the achieving of our target bandwidth with compact size challenging.…”

Characteristics mode analysis based wideband Sub-6 GHz flexible MIMO antenna using a unique hybrid decoupling structure for wearable applications

“…Wireless wearable technology has been showing exponential growth ever since its evolution and has gained the deep focus of researchers in the past few years. The broad arena of wearable technology applications including health monitoring, skin cancer detection, flexible biosensors, implantable wearables, sports, military applications, IoT (Internet of Things), and many more has led to a sudden increase in device usage by 90% from 2015 to 2020 [1,2]. High-speed communication with uninterrupted service is essential in the above-mentioned applications which makes 5G communication a promising opportunity for the same.…”

“…The higher band called the millimeter wave band operates at a range of 24-300 GHz. The sub-6 GHz band attracts researchers due to its exclusive property of stronger penetration capability and feasible long-distance communication with a large cell coverage area [2]. Antennas being the backbone of deployment of any wearable wireless technology, flexible microstrip antennas are ruling the wearable market due to their peculiar characteristics like high flexibility, lightweight, and conformality [3].…”

“…However, the implementation of conformal MIMO systems faces several challenges including better isolation, directional radiation characteristics, and maintaining stable bandwidth [8]. Numerous approaches are seen in the literature for improving the isolation between the inter-elements such as incorporating slots [9,10], stubs [11,12], metamaterial [13], defected ground plane (DGS) [2,14], electromagnetic band gap structures (EBG) [15], neutralization lines (NL) [16] or hybrid (combination of any two of the specified techniques) [7]. Even though the above-mentioned techniques help provide the isolation, optimizing the MIMO antenna decoupling structures maintaining the operating bandwidth, stable gain, radiation efficiency, and desired directional radiation patterns with a low antenna volume is challenging [17,18].…”

“…Literature shows several wearable MIMO antennas covering Sub-6 GHz band. A Sub-6 GHz MIMO antenna with a defective ground structure is proposed in [2] to get an improved isolation among the antenna elements. The antenna integrated on the wrist showed satisfactory SAR limits, however, the gain of the antenna is affected due to the defects created in the ground plane due to the back radiation which deteriorates the gain of the antenna.…”