A Compact and Straightforward Self-Decoupled MIMO Antenna System for 5G Applications

Abstract

This study investigates a compact and straightforward self-decoupled 2 × 2 multiple-input multiple-output (MIMO) antenna set and its applications for current and future 5G terminal devices. The proposed self-decoupled MIMO antennas include a popularly used loop antenna and a compact loop-type ground-radiation antenna without utilizing any supplementary decoupling structures or undergoing complex tuning process. It is revealed that the loop antenna and the ground-radiation antenna can be modeled as an electric-current element and a magnetic-current element, respectively. This orthogonality allows the selfdecoupled characteristic of the proposed MIMO antennas even though the antenna elements are tightly arranged and collocated together. An 8 × 8 MIMO antenna system is further demonstrated for 5G MIMO applications, where both simulation and measurement are conducted to validate the feasibility of the proposed technique. It is concluded that the proposed MIMO antenna system is a smart way to generate high isolation and low correlation characteristics while having advantages of low profile and easy fabrication so that it can be recognized as a promising candidate for 5G applications. INDEX TERMS Multiple-input multiple-output (MIMO), 5G, terminal devices, loop antenna, groundradiation antenna, orthogonality.

Compact SIW Fed Dual-Port Single Element Annular Slot MIMO Antenna for 5G mmWave Applications

“…The maximum efficiency attained at the resonant frequency is 92.7%. Similarly, self-decoupled 2×2 MIMO antenna based on a combination of loop antenna and loop type ground radiation antenna has been proposed in [20]. Due to the orthogonality in loop and ground radiation antenna no decoupling network is required to decouple the antennas in spite of their tight arrangement.…”

Four-Port Wide-Band Cavity-Backed Antenna With Isolating X-Shaped Block for Sub-6 GHz 5G Indoor Base Stations

“…The isolation between ports is a critical parameter, specially when multiple-port solutions are mounted in limited space scenarios. Some of the techniques used for increasing isolation are based on using a decoupling element [10], a neutralization line [11], orthogonal polarizations [12]- [17], decoupling networks [18] and self-isolated/self-decoupled [19]- [21] antennas. In addition, the interest on Characteristic Modes Analysis (CMA) in modern applications [22] has increased due to the possibility of exciting different orthogonal modes on a radiating ground plane of a hand-held device for MIMO compatibility.…”

Eight‐element self‐decoupled MIMO antenna design for 5G smartphones

“…Isolation of 17.5 dB and total efficiency of more than 55% are obtained in the 3.5 GHz band. In Reference 15, self‐decoupled pairs including a loop antenna on the wall and a compact ground antenna based on the orthogonality between the equivalent models are designed and resonant at the 3.5 GHz band (−6 dB), an isolation level of 20 dB is obtained in the 8 × 8 MIMO system. The decoupled pairs in Reference 16 is based on pattern diversity which yields two opposite port current distributions, and the eight‐element MIMO array obtains isolations of 14 dB and efficiencies of more than 52%.…”