2020 International Workshop on Antenna Technology (iWAT)

MACKEY type S miniaturized using short circuit
plate
1st Toshiki Tamura

2nd Shigeru Makino

3rd Kenji Itoh

Kanazawa Institute of Technology
7-1 Ogigaoka, Nonoichishi,Ishikawa, 921-8501 Japanb1547223@planet.kanazawa-it.ac.jp

Kanazawa Institute of Technology
7-1 Ogigaoka, Nonoichishi,Ishikawa, 921-8501 Japanmakino@neptune.kanazawa-it.ac.jp

Kanazawa Institute of Technology
7-1 Ogigaoka, Nonoichishi,Ishikawa, 921-8501 Japanitoh.kenji@neptune.kanazawa-it.ac.jp

Abstract—Meta-surface inspired antenna chip developed byKIT EOE Laboratory (MACKEY) that operates not only in afree space but also on a metal plate has proposed. In this paper,
two new types of MACKEY with shorting plates and how tomake them are proposed.
Index Terms—MACKEY , Through hole , thermoplastic
polyurethane film , short circuit plate

I. I NTRODUCTION
A meta-surface inspired antenna chip developed by KIT
EOE Laboratory (MACKEY), which integrates a dipole antenna and an artificial magnetic conductor (AMC), has beendeveloped[1]. The MACKEY chip has proved its capabilitiesof matching the impedance even when installed in a free spaceor on a metal plate.
In this paper, two new types of MACKEY chips withshorting plates, as well as a process for their manufacture,are proposed.
II. S TRUCTURE OF ORIGINAL MACKEY
Fig.1 depicts a model diagram of MACKEY basic type.
From top to bottom, it comprises an antenna plate, a gridplate, and a metal plate. A dielectric layer is placed between
each of them. Impedance matching can be achieved using thedesign parameters g and ℓ. Fig.2 depicts the analysis results ofthe VSWR characteristics, indicating that the MACKEY chipcan operate not only in a free space but also on a metal plate.

Fig. 1. Model diagram of the basic MACKEY basic type.

978-1-7281-2640-1/20/$31.00 ©2020 IEEE

Fig. 2. VSWR characteristics of the basic MACKEY basic type.

III. M ODEL DIAGRAMS AND MEASURED VALUES OF THE
S1- AND S2- TYPE MACKEY S
The MACKEY basic type presented in Fig.3(B) only uses
two elements (separated by dotted lines in the figure) of an
AMC based capacitance grid of the infinite periodic structureof Fig.3(A). The mirror image principle is used to miniaturize
the basic type. Fig.3(C) and Fig.3(D) depicts how the miniaturization is conducted.
Fig.3(C) is a model in which the basic type of Fig.3 (B)is cut in half along the dotted line and a short-circuit plate isprovided. The structure of Fig.3(B) is a target structure by adotted line. Fig.3(C) in which a short-circuit plate is provided
by cutting in half with a dotted line is equivalent to Fig.3(B)from the principle of mirror image. The MACKEY type S1,
which is miniaturized by shorting one side, has been proposed.
Fig.3(D) depicts a model in which a short circuit plate is
installed at the dotted line portion of the capacitance grid inFig.3(A), as well as a dipole antenna placed thereon. The
model in which only the two elements in Fig.3(A) are left
cut by a dotted line, and the short-circuit plate is installed,
is equivalent to the model depicted in Fig.3(A) owing tothe mirror image principle. The model with a dipole antenna
placed on top is presented in Fig.3(D). MACKEY type S2,
which is miniaturized by shorting on both sides, has been
proposed. Compare the width L and the specific bandwidthof the basic model and the two S models.

2020 International Workshop on Antenna Technology (iWAT)

is 60% smaller than that of the basic type, with a width of 54.7mm. The substrate width of the type S2 MACKEY is 47.2 mm,
which is 86% smaller than that of the basic type, with a widthof 54.7 mm. Fig.11 and Fig.12 show the VSWR characteristics
analysis results of the S1- and S2-type MACKEYs using
through-holes, respectively. The type S1 is narrower than thebasic type. The type S2 has a wider bandwidth than the basic
type. However, it is affected by metal.

Fig. 3. Model diagram of small MACKEY.

IV. S TUDY OF THE MACKEY TYPE S SHORT CIRCUIT
PLATEThere are two possible methods for creating the short-circuit
plate. The first is to open a through hole and short it. Thismethod is generally used as a means for short-circuiting.
However, to open the hole, it is necessary to ensure that
additional space is available to accommodate it; this requires alarger model, which is a drawback. With the second method,a short-circuit plate is created by sticking the thermoplastic
polyurethane (TPU) film to cover the side and bottom. TPUfilm is composed of an 18 μ m electrolytic copper foiltransferred 30 μ m TPU hot melt bond film. The TPU film isthin. By creating a short-circuit board via sticking TPU film,
the resultant model size will be smaller than that if using athrough-hole. A comparison analysis of the results and themodel dimensions of the two mentioned creation methods ispresented in the following figure.

Fig. 5. Model diagram of the MACKEY type S1 using through hole.

Fig. 6. Model diagram of the MACKEY type S2 using through hole.

Fig. 7. VSWR characteristics of the MACKEY type S1 using through hole.

Fig. 4. Model diagram of MACKEY type S using through hole.

V. S TUDY OF MACKEY TYPE S USING THROUGH HOLE
Fig.9 and Fig.10 depict the model diagrams of S1- and S2type MACKEYs using through-holes, respectively. A throughhole with a diameter of 0.5 mm is opened on one side ofthe type S1 and on both sides of the S2 type. The MACKEY
chip is miniaturized by short-circuiting the through hole. Thesubstrate width of the type S1 MACKEY is 32.55 mm, which

Fig. 8. VSWR characteristics of the MACKEY type S2 using through hole.

VI. S TUDY OF MACKEY TYPE S USING TPU FILM
Fig.9 and Fig.10 present the model diagrams of the S1and S2-type MACKEYs using TPU film, respectively. The

2020 International Workshop on Antenna Technology (iWAT)

MACKEY chip is miniaturized via short-circuiting using TPUfilm. The substrate width of the MACKEY type S1 is 29.05
mm, which is 53% smaller than the basic type with a width of54.7 mm. The substrate width of the MACKEY type S2 is 37.4mm, which is 68% smaller than the basic type with a width of
54.7 mm. Fig.11 and Fig.12 present the VSWR characteristics
analysis results of the S1- and S2-type MACKEYs using TPU
film. The type S1 is narrower than the basic type. The typeS2 has a wider bandwidth than the basic type. However, it isaffected by metal.

VII. C OMPARISON OF MACKEY TYPE S CREATIONMETHODS

Table.I presents a comparison of the width L between themodel using TPU film and the model using through holes(SH). When comparing the width L of a board having aTPU film and through holes, the type S1 has little change ofsize. However, the type S2 was approximately 10 mm wider
when made with through holes. When comparing the specificbandwidth of a board created with a TPU and a SH, the typehas little change. The type S2 was made with SH. However, thespecific bandwidth was wider and the effect on the metal waslarger. With both methods, the miniaturization is successful
because the obtained width L is smaller than the width of thebasic type.
TABLE IC OMPARISON OF WIDTH Lwidth L : [mm]Fig. 9. Model diagram of the MACKEY type S1 using through hole.

Fig. 10. Model diagram of the MACKEY type S2 using through hole.

type S1TPUSH
29.05
32.55

type S2TPU SH
37.4
47.2

VIII. C ONCLUSION
A basic MACKEY type was miniaturized using the mirror
image principle, and an MACKEY type S1 and doublesided short-circuit type MACKEY were proposed. The width
L and the specific bandwidth of the basic model and thetwo S models were compared. Both methods succeeded inminiaturization because the width L is smaller than the widthof the basic type. The type S1 became narrower and the typeS2 became wider. However, the type S2 has a large influence
on metal.
The analysis results of two creation methods, namely usinga through hole and using TPU film, were compared. For thetype S1, the width L and the analysis results hardly changed
compared with the board having a TPU film. For the type S2,the width L is approximately 10 mm larger when a TPU film
is used. Moreover, the specific bandwidth is widened.
IX. ACKNOWLEDGMENTS
This work was supported by JSPS KAKENHI (15K06089).
R EFERENCES

Fig. 11. VSWR characteristics of the MACKEY type S1 using through hole.

Fig. 12. VSWR characteristics of the MACKEY type S2 using through hole.

[1] T. MOROYA et al, AMC Inspired Small Antenna MACKEY, IEICE.
Trans. Commun, vol. J99-B, no. 9, pp. 786794, Sep. 2016.
[2] T. MOROYA et al, AMC Inspired Small Antenna MACKEY, IEICE.
Tech. Rep, AP2015-6, pp. 25-30, 2015.