Efficient Isolation of an MIMO Antenna Using Defected Ground Structure

Haoran Xing,Mengjun Wang,Xinyan Wang,Xing An,Hong-Xing Zheng,Erping Li,Zhenbin Gao

doi:10.3390/electronics9081265

Haoran Xing, Mengjun Wang + Show 5 more

Open Access

https://doi.org/10.3390/electronics9081265

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Journal: Electronics	Publication Date: Aug 6, 2020
Citations: 28	License type: CC BY 4.0

Affiliation: Hebei University of Technology, Zhejiang University

Abstract

To implement efficient isolation between units of a multi-input multi-output (MIMO) antenna, a defected ground structure (DGS) has been investigated. An antenna with two elements operating at 5.8 GHz and fed by coaxial is considered. To reduce mutual coupling between the elements, a zigzag groove is inserted into the center of two elements formed as a DGS. To verify this design, a scattering matrix was tested, such as reflection coefficient S11 and transmission coefficient S21 between two element ports. Meanwhile, radiation pattern, current distribution, envelope correlation coefficient (ECC), and diversity gain of the antenna were simulated and measured. The results showed that the mutual coupling was reduced by 28.8 dB when a DGS was used, and the ECC was less than 0.02. Owing to these good performances, each antenna element can operate almost independently, and this MIMO antenna can be efficiently applied to the narrow band Internet of Things system.

Highlights

Wireless communication systems must provide large channel capacity and high reliability requirements
If the defected ground structure (DGS) is with one zigzag groove unit only, the location of this unit is considered first
As can be seen from the results of S21, when the DGS unit unit simulations are located at the top and bottom positions, the isolations are better than when the simulations are located at the top and bottom positions, the isolations are better than when the DGS

Summary

Introduction

Wireless communication systems must provide large channel capacity and high reliability requirements. These indexes can be achieved by utilizing multi-input multi-output (MIMO) antenna technology [1]. The microstrip antenna introduces several advantages such as simple structure, low profile, easy fabrication, and conformal shape as the prioritized candidates of multiple elements [2]. Surface waves and near fields can lead to coupling between the antenna elements. This coupling often affects radiation and frequency response characteristics seriously. The near field coupling is very strong in the situation where the antenna is printed on

Methods

Discussion

Conclusion