Multi-Band and High Gain Antenna Using AMC Ground Characterized With Four Zero-Phases of Reflection Coefficient

Yajie Gong,Yinchao Chen,Shuhui Yang,Fanglu Tong,Chenyin Yu,Bin Li

doi:10.1109/access.2020.3024982

Yajie Gong, Yinchao Chen + Show 4 more

Open Access

https://doi.org/10.1109/access.2020.3024982

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Abstract

In this paper, a multi-band AMC-backed antenna system characterized with high gain and low-profile is proposed. It is constructed by placing a quad-band coplanar-waveguide (CPW) antenna over an AMC with four zero-phases in the reflection coefficient. The CPW antenna consists of an ornamental-pillar-shaped patch with the specially designed parasitic elements, and a defected ground structure (DGS), for the application in the frequency bands of 2.45, 3.5, 4.6 and 5.8 GHz. To improve the CPW antenna’s radiation performance, an artificial magnetic conductor (AMC) ground with four zero-phases of the reflection coefficient is designed and employed as the reflector. The AMC unit cell is composed of four metallic nested rings (FMNR), whose innermost ring is connected in series to four lumped capacitors. It is observed that the proposed quad-band AMC ground can not only increase the gains of the multi-band antenna greatly but also combine the two intermediate frequency bands of the antenna into a broadband one. The prototypes of the antenna and the AMC array with $5\times {5}$ unit cells were fabricated and measured. It is found that in comparison to the antenna without AMC, the AMC-backed antenna obtains a gain enhancement by amounts of 4.93, 5.92, 5.54 and 4.95 dB at the frequencies of 2.45, 3.5, 4.6 and 5.8 GHz. The 10-dB impedance bandwidths of the AMC-backed antenna include three bands of 2.13–2.87, 3.22–4.75, and 5.54–5.86 GHz, with the corresponding relative bandwidths of 14.8%, 38.4%, and 5.3%. The proposed antenna can be potentially applied to the applications in WLAN, WiMAX, and 5G mobile communication systems.

Highlights

With the rapid development of various wireless communication systems, design of multi-band microstrip antennas has received great attention from researchers in both academic and industrial fields
To improve antenna gain performance, three kinds of structures are frequently used for a radiation reflector, namely, perfect electric conductor (PEC) [5], [6], partially reflecting surface (PRS) [7]–[10], and artificial magnetic conductor (AMC) [11]–[29]
It mainly consists of an ornamentalpillar-shaped patch with the specially designed parasitic elements, and a defected ground structure etched with two square rings

Summary

Introduction

With the rapid development of various wireless communication systems, design of multi-band microstrip antennas has received great attention from researchers in both academic and industrial fields. Various approaches for designing multi-band antennas have been developed and investigated [1]–[4]. As discussed in [1], by etching two mental-insulator-mental (MIM) rings on a square patch, the surface current distributions have been changed, which effectively improves radiation and leads to form a multi-band antenna. A single antenna structure is often inadequate to meet the high demands for multi-band communication. Further efforts are required to design high standard multi-band antennas in terms of dimension, directionality, gain, and impedance bandwidth. To improve antenna gain performance, three kinds of structures are frequently used for a radiation reflector, namely, perfect electric conductor (PEC) [5], [6], partially reflecting surface (PRS) [7]–[10], and artificial magnetic conductor (AMC) [11]–[29].

Methods

Conclusion