Dual band MACEY type T composed of three radiating grids
for WiFi 2/5 GHz application
Shigeru MAKINO1 Ken HIRANO 2 Kenji ITOH2 Keisuke NOGUCHI2 Tetsuo HIROTA2Abstract − A meta-surface inspired antenna (MACKEY)
has been proposed, which works not only in free space
but also on a metal plate. A MACKEY parallel
arrangement model will be proposed in which an
original MACKEY (WiFi 2 GHz band) and a
MACKEY wide-band type (WiFi 5 GHz band) arearranged in parallel. Then, a MACKEY type T will be
proposed, where one of the two grids of an original
Mackey and that of a wide-band type are shared.

Introduction

g s=0.5䐠

t=3.12

䐡

Original MACKEY

sp gg s=0.5

ggg

䐠 Grid plate

Wide-bandtype

L=2(g+gg+s)+sp

Side view

Metal plate

s=0.5

䐟Antenna plate䐟

h=0.74

ƐƐ

ww

s=0.5

Dielectric䐡 Metal plate

Fig. 1. Structure of a parallel arrangement model.
2.2 Analyzed Result
The design parameters of the parallel arrangement
model are g = 26.8 mm, gg = 10 mm, Ɛ = 27.9 mm, ƐƐ= 14.3 mm, sp = 4 mm, and ww = 1.0 mm. Therefore,the size is 30 mm  79.5 mm  4.0 mm. Fig. 2shows the VSWR characteristic of the parallel
arrangement model in free space and illustrates that theparallel arrangement model covers the WiFi 2 GHz / 5GHz bands. Fig. 3 shows the radiation patterns of theparallel arrangement model in free space at 2.45 GHz,5.25 GHz and 5.60 GHz, respectively. From Fig. 3, theanalyzed gains are 6.1 dBi, 5.8 dBi, and 7.6 dBi,
respectively. Therefore, the parallel arrangement
model works for WiFi 2 GHz / 5 GHz bands and theminimum sp is 4 mm to reduce the influence of mutualcoupling.
1098765432110987654321VSWR

An antenna model MACKEY integrating a dipoleantenna and an artificial magnetic conductor (AMC)
has been developed [1]. It was shown that theMACKEY can match the impedance even when
installed in free space or on a metal plate.
The proposed MACKEY satisfies each of WiFi 2
GHz and WiFi 5 GHz bands. However, one antenna
cannot cover these bands as the bandwidth of WiFi 5GHz is too wide. In order to obtain dual-bandcharacteristics, a MACKEY parallel arrangement
model will be proposed in which an original
MACKEY (WiFi 2 GHz band) and a MACKEY wideband type (WiFi 5 GHz band) are arranged in parallel[2]. Then, a MACKEY type T model will be proposed
to reduce the size, where one of the two grids of an
original Mackey and that of a wide-band type areshared.
2.

ƐW=30

Parallel Arrangement Model

2.1 Structure of Parallel Arrangement Model

VSWR

1.

Feedingpoint

2

Fig. 1 shows the structure of the parallel arrangement
model. It is composed of two dipole antenna, four grids
and two metal plates in order from the top, anddielectric substrate among them. In WiFi 2 GHz band,
impedance matching is possible by determining theoptimum combination of Ɛ and g. In WiFi 5 GHz band,
impedance matching is possible by determining theoptimum combination of ƐƐ and gg. The slit width (sp)is a distinctive parameter for the parallel arrangement
model, and is provided to reduce the influence of
mutual coupling.

2.1

2.2

2.3

2.4

2.5

2.6

Frequency[GHz]

2.7

2.8

in free spce(2GHz䡚3GHz)

2.93

5

5.1

5.2

5.3

5.4

5.5

5.6

Frequency[GHz]Fig. 2. VSWR characteristicsl.

Fig. 3. Radiation patterns.

,(((________________________________________________________________________________________
1
2

Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichi, Ishikawa, 921-8501, Japan, Email: makino@neptune.kanazawa-it.ac.jp.
Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichi, Ishikawa, 921-8501, Japan.
718

5.7

5.8

in free spce(5GHz䡚6GHz)

5.96

MACKEY type T

3.2 Measured Result

3.1 Idea of MACKEY type TFig. 6 shows the VSWR characteristics of type T in
free space and on a metal plate. The solid black andred lines indicate the VSWR characteristics obtained
from the analyzed results and the measured results,respectively. From Fig. 6, the analyzed results and themeasured results coincide very well. The measured
bandwidth in free space is more than 6.5 % (2 - 3GHz) and 13.6 % (5 - 6 GHz) and covers the WiFi 2GHz / 5 GHz bands. The measured bandwidth on ametal plate is more than 4.2 % (2 - 3 GHz) and 16.0 %(5 - 6 GHz) and covers the WiFi 2 GHz / 5 GHz bands.
Fig. 7 shows the radiation patterns of type T modelin free space at 2.45 GHz, 5.25 GHz and 5.60 GHz,
respectively. The black and red lines indicate theradiation patterns obtained from the analyzed results
and measured results, respectively. In the figure, thesolid lines indicate the Eș component. From Fig. 6, themeasured gains are 5.5 dBi, 4.5 dBi, and 3.6 dBi,respectively. Fig. 8 shows the radiation patterns oftype T model on a metal plate at 2.45 GHz, 5.25 GHz,and 5.6 GHz, respectively. From Fig. 8, the measured
gains are 8.5 dBi, 6.0 dBi, and 6.3 dBi, respectively.
Therefore, type T model is shown to not only workin free space but also on a metal plate over the WiFi 2
GHz / 5 GHz bands.

A method for sharing the grids of the original
MACKEY and the wide-band type is proposed toreduce L of the parallel arrangement model [2]. Fig. 4
shows the sharing model of the grids. The green dottedline works in the WiFi 2 GHz band, and the blue dottedline works in the WiFi 5 GHz band. Compared with theparallel arrangement model, the overlapping part of thegreen and blue dotted lines works as a grid of different
frequency bands. Therefore, the number of grids
becomes triple, and L is small. A MACKEY type T isproposed, where the number of grids is triple. The grid
widths corresponding to one frequency are asymmetricon the left and right. In the figure, the slit of WiFi 2GHz band acts as sp to reduce the influence of mutual
coupling. Therefore, the sp of the grid in WiFi 2 GHzband is set to 4 mm where the influence of mutual
coupling is small. Also, the slit of WiFi 5 GHz band isset to 0.5 mm.
sp

Antenna for WiFi 2 GHz
Antenna for WiFi 5 GHz

MACKEY parallel arrangement type䐠䐡䐟䐠 Antenna for WiFi 2 GHz

10987654321

䐠䐡 Antenna for WiFi 5 GHzVSWR

sp

10987654321MACKEY type T (Triple grids type)Fig. 4. Idea to reduce length of a parallel arrangement
model.

VSWR䐟

Analysis
Measure
2

2.1

2.3

2.4

2.5

2.6

Frequency[GHz]

2.7

2.8

2.9

Analysis
MeasureVSWR

Fig. 5 shows the design parameters of type T. As aresult of designing type A that covers the WiFi 2 GHz/ 5 GHz bands, the shared grid width (gg) is set to 8mm. For type T in the WiFi 2 GHz band, impedance
matching is possible by determining the optimum
combination of ƐƐ1 and g1. For type T in the WiFi 5GHz band, impedance matching is possible bydetermining the optimum combination of ƐƐ2 and g2.
The size of the designed type T is 30 mm  56.8 mm
 4.0 mm, which is downsized by about 30%
compared with the parallel arrangement model.

Analysis
Measure23in free space (2GHz䡚3GHz)

10
98
76
543
21

3.2 Structure of a MACKEY type T

2.2

2.1

2.2

2.3

2.4

2.5

2.6

Frequency[GHz]

10
98
76
54
321

sp=4

5

5.1

5.2

5.3

5.4

5.5

5.6

Frequency[GHz]

5.7

5.8

in free space (5GHz䡚6GHz)

5.9

65

5.1

5GHz䡚6GHz

5.2

5.3

5.4

5.55.6Frequency[GHz]

sp=4

s=0.5

4Fig. 6. Comparison of VSWR characteristics.

Side view

s=0.5
ƐƐ2=12.

ww1=8.3

s=0.5
gg=8

g1=36.8

5.7

on metal (5GHz䡚6GHz)

ƐƐ1=36.8

W

s=0.5w

Top view

Fig. 5. Structure of a MACKEY type T.

719

2.8

2.9

3

5.8

5.9

6Analysis
MeasureL=g+g1+g2+sp+s=56.8
s=0.5

2.7

on metal (2GHz䡚3GHz)

VSWR

3.

Fig. 7. Radiation patterns in free space.

Fig. 8. Radiation patterns on a metal plate.
4.

Conclusion

The MACKEY type T has been proposed, whichworks in the WiFi 2 GHz / 5 GHz bands; it works infree space as well as on a metal plate. Also, type T wasdownsized by about 30% compared with the parallel
arrangement model.
References
[1]

[2]

T. MOROYA et al, “AMC Inspired Small Antenna MACKEY,”
IEICE. Trans. Commun, vol. J99-B, no. 9, pp. 786–794, Sep.
2016.
K. HIRANO et al, “Feasibility Study of MACKEY type A,” IEICE.
Tech. Rep, AP2017-110, pp. 15-20, 2017.

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