Compact Wideband MIMO Diversity Antenna for Mobile Applications Using Multi-Layered Structure

Abstract

A closely packed wideband multiple-input multiple-output (MIMO)/diversity antenna (of two ports) with a small size of less than 18.5 mm by 18.5 mm is proposed for mobile communication applications. The antenna can be orthogonally configured for corner installation or by placing it on a back-to-back structure for compact modules. To enhance the isolation and widen the bandwidth, the antenna is structured with multiple layers having differing dielectric constants. The feeding through a via significantly reduces the ground waves. A multi-fidelity surrogate model-assisted design exploration method is employed to obtain the optimized antenna geometric parameters efficiently. The antenna design was investigated using electromagnetic simulation and a physical realization of the optimal design was then created and subjected to a range of tests. The specific parameters investigated included reflection coefficients, mutual coupling between the input ports, radiation patterns, efficiency and parameters specific to MIMO behavior: envelope correlation coefficient and pattern diversity multiplexing coefficient. It was found that the antenna has an impedance bandwidth of approximately 4 GHz, mutual coupling between input ports of better than −18 dB and an envelope correlation coefficient of less than 0.002 across the operating band. This makes it a good candidate design for many mobile MIMO applications.

Design and Analysis of Modified U-Shaped Four Element MIMO Antenna for Dual-Band 5G Millimeter Wave Applications

“…The recommended MIMO antenna performance has been compared to other antennae that have been previously described in Table 1 . It is evident that most MIMO antenna configurations discussed in [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ] are larger than the suggested antenna, thereby limiting their suitability for usage with modern compact devices. When compared to the existing antennae, it is evident that the recommended design outperforms them in terms of size, impedance bandwidth, isolation, peak gain, ECC, DG, TARC, CCL, and MEG.…”

“…Consequently, improving isolation or reducing mutual coupling between adjacent antenna presents a challenge [ 6 , 7 , 8 , 9 ]. Extensive research has already been conducted to address isolation improvement and mutual coupling reduction in MIMO antenna systems [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ].…”

“…For 2-element MIMO antenna systems, several approaches have been developed to enhance isolation [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. These approaches include the use of rectangular ground slots [ 10 ], inverted antenna elements with high spacing [ 11 ], a rectangular micro-strip stub with a defected ground plane [ 12 ], narrow and T-shaped slots on the ground plane [ 13 ], DGS with a T-shaped stub on the ground [ 14 ], orthogonal arrangement of antenna elements [ 15 ], diversity in antenna element placement [ 16 ], antenna with multiple layers having different dielectric constants [ 17 ], inverted arrangement of radiators [ 18 , 19 ], and double-side EBG (DS-EBG) structure [ 20 ]. Furthermore, various methods for improving isolation in four element MIMO systems have been established [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ].…”

Dual-Band MIMO Antenna Design for 5G Smartphones Mobile Communications

“…Multiple-input multiple-output (MIMO) techniques can then ominously progress the range operation and channel capabilities in communication systems without boosting transmit power and adding extra transmission bandwidth. On the other hand, as the miniaturization and prospect of wireless appliances turn out to be the distinctive mainstream, the manageable clusters for the antenna are beyond insufficient [15][16]. Consequently, it is exceptionally vital to launch an effective MIMO antenna.…”

Design and Characterization of Compact Broadband Antenna and Its MIMO Configuration for 28 GHz 5G Applications

“…The antenna operates at 6 GHz with a bandwidth of 4.5-8.5 GHz. The proposed antenna has simple geometry but a multi-layered structure [27]. A four-port MIMO dipole antenna array for 28 GHz is presented in [28].…”