2022 International Conference on Emerging Technologies for Communications (ICETC 2022)1

Study of Circularly-Polarized MACKEY with Two-Point FeedMichinori Yoneda†a), Student member, Keito YOKOE†, Student member, Shigeru MAKINO†, Fellow Member

3. Analysis Results for MACKEY CP
1. Introduction

10987
6
5
4
3
2
1VSWR

2. Proposal for MACKEY CP

In this study, to investigate the possibility of circularpolarization by MACKEY, power feeding is performed
under ideal conditions of equal amplitude and a phasedifference of 0° and 90° respectively. The analysis isperformed using an electromagnetic simulator (ANSYS,HFSS) based on the finite-element method. Fig. 2 shows
VSWR and axis ratio in free space and on metal. It also
shows that the bandwidth where VSWR is less than threeis wider than the 2.4–2.5 GHz. The axial ratio is almost 0dB. Fig. 3 shows that the realized gain in the frontal
direction is 3.73 dB in free space and 4.86 dB on the metal.

Fig. 1 shows a model diagram of MACKEY CP. MACKEY
CP combines MACKEY II orthogonally and feeds powerwith equal amplitude and a phase difference of 90° to thetwo feed points to radiate circularly polarized waves with anantenna size of approximately (λ/2)2. In this study, weevaluate the relative bandwidth satisfying a VSWR (voltagestanding wave ratio) of three or less and an axial ratio of 3dB or less in free space and on metal when the center
frequency is 2.45 GHz.

109876543210Axial Ratio[dB]

The metasurface-inspired antenna chip developed by theKIT EOE Laboratory (MACKEY) [1] was devised as arobust antenna that is not affected by surrounding metals. In
this report, we propose a new model, MACKEY CP type
(hereinafter referred to as "MACKEY CP"). This
proposition is based on MACKEY II [2], a thinner versionof MACKEY that uses an inverted L element for unbalanced
power supply, along with four grid plates and two parasitic
elements to change the polarization from conventional linear
to circular.

2.3

2.4
2.5
2.6
Frequency[GHz]in_free_space
on_metal

2.3

2.4
2.5
2.6
Frequency[GHz]in_free_space
on_metalFig. 2 VSWR and Axial RatioXY PlaneXZ Plane

10 X

10 Z

00-10-10Y-20

LHCP

RHCP

LHCP

RHCP-20X

Fig. 3 Radiation Pattern
4. Conclusion

L= 72.3ℓ=33.0s=1

L= 72.3Feedingpoint

L= 72.3

L= 2×g + s = 72.3
g= 35.65

s=1(1) Grid plate

Acknowledgments

50Ω termination(2)

Antenna plate

This study confirmed that MACKEY CP radiates
circularly polarized waves with good axial ratio
performance. In the future, we could investigate simpler
ways to feed power, such as using one feeding point.

(3) metal plate

Fig. 1 MACKEY CP Model Diagram

This work was supported by JST CREST (Grant Number
JPMJCR20Q1), Japan.
References†The author is with Kanazawa Institute of Technologya)

E-mail: b1812587@planet.kanazawa-it.ac.jp[1]

T. Moroya, et al., “AMC-inspired small antenna MACKEY,”[2]

IEICE. Trans. Commun., vol. J99-B, no. 9, pp. 786–794, September
2016.
K. Miyashita, S. Makino, and K. Itoh, “Feasibility study of anunbalanced MACKEY type R with enhanced robustness on metal,” inISAP 2021, October 2021.JCopyright © 2022 The Institute of Electronics, Information and Communication Engineers

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