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

Haiyan Piao,Yunnan Jin,Longyue Qu

doi:10.1109/access.2020.3008966

Abstract

This study investigates a compact and straightforward self-decoupled $2\times 2$ 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 self-decoupled characteristic of the proposed MIMO antennas even though the antenna elements are tightly arranged and collocated together. An $8\times 8$ 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.

Highlights

Multiple-input multiple-output (MIMO), utilizing multiple antenna elements for simultaneous transmission and reception at the same radio channel without increasing the input power or frequency spectrum, is a critical technology to increase the channel capacity and provide high data rate for 4G Long-Term Evolution (LTE) applications and the generation wireless communication (5G) [1], [2]
In this paper, a simple and compact self-decoupled MIMO antenna set is accomplished by merely assembling a loop antenna and a ground-radiation antenna
It has been demonstrated that the high isolation property is obtained due to the orthogonality between the equivalent electric-current element of the loop antenna and the equivalent magnetic-current element of the ground-radiation antenna

Summary

INTRODUCTION

Multiple-input multiple-output (MIMO), utilizing multiple antenna elements for simultaneous transmission and reception at the same radio channel without increasing the input power or frequency spectrum, is a critical technology to increase the channel capacity and provide high data rate for 4G Long-Term Evolution (LTE) applications and the generation wireless communication (5G) [1], [2]. In this way, the ground-radiation antenna is operating as a magnetic coupling element and exciting the ground plane for far-field radiation, just as the name of the ground-radiation antenna implies. The radiated electric fields from J1 are orthogonal to those from M2; this orthogonality characteristic between the two current elements ensures the high isolation characteristic between the two antennas, allowing successful implementation of the proposed self-decoupled MIMO antenna set. The loop antenna is symmetrically installed outside of the ground-radiation antenna, establishing a planar design of the proposed self-decoupled MIMO antenna set.

FABRICATION AND MEASUREMENT

Findings

CONCLUSION