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

Arabi, Omer; See, Chan Hwang; Ullah, Atta; Ali, Nazar; Liu, Bo; Abd-Alhameed, Raed; McEwan, Neil J.; Excell, Peter S.

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.

• Journal Article Type: Article
• Acceptance Date: Aug 12, 2020
• Online Publication Date: Aug 14, 2020
• Publication Date: Aug 14, 2020
• Deposit Date: Aug 13, 2020
• Publicly Available Date: Aug 14, 2020
• Journal: Electronics
• Electronic ISSN: 2079-9292
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 8
• Article Number: 1307
• DOI: https://doi.org/10.3390/electronics9081307
• Keywords: multiple-input multiple-output (MIMO); mutual coupling; polarization diversity; Nelder–Mead method (NM); surrogate-assisted differential evolution algorithm (SADEA)
• Public URL: http://researchrepository.napier.ac.uk/Output/2681366