Experimental and Numerical Study of Electromagnetic Waves Shielding by Metamaterial Structures
Yi-Shen Chen
1, Chin-Hsiang Cheng
2, Hsin-Yu Tsai
3and David. T. W. Lin
41,2,3
Institute of Aeronautics and Astronautics, National Cheng Kung University, Tainan, Taiwan.
4
Institute of Mechatronic System Engineering, National University of Tainan, Tainan, Taiwan.
ACEX285
Institute of Aeronautics and Astronautics, National Cheng Kung University, Tainan, Taiwan.
p48981081@mail.ncku.edu.tw
2 21 2
1− S11 − S α =
= 0
⋅
∇
=
⋅
∇
∂ + ∂
=
×
∇
∂
− ∂
=
×
∇
B D
t J D
H
t E B
ρ
Maxwell’s equations Electromagnetic wave equation:
2 2
( E) k n E 0
∇× ∇× − =
2 2
(n− H ) k H 0
∇× ∇× − =
Scattering parameters, S
1 11
1
S b
= a 21 2
1
S b
= a
Absorptivity=1-refractivity-transmissivity Shielding coefficient:
“Metamaterial” is a unique material which has negative permittivity and negative magnetic permeability as well, which can be fabricated by embedding micro scale metallic structures in dielectric materials. The structures may be properly designed to yield different electro- magnetic and optical properties on demand. In this study, a metamaterial structure is analysed experimentally and numerically to achieve high shielding effects for the electromagnetic wave.
Silver Polyimide, PI
2
1− S21
γ =
L=5mm
L=6mm
L=7mm
Electric Field Magnetic Field L
L
L (mm) Frequency 5 6.5GHz 6 5.3 GHz 7 4.3 GHz
Numerical simulation shows that with silver pattern at 0.5- mm width on Polyimid layer, pattern sizes of 5mm× 5mm, 6mm × 6mm and 7mm × 7mm show great shielding effectly specifically for frequencies of 6.5, 5.3 and 4.3 GHz, respectively. According to experimental data, the operating frequencies are 6.55, 5.43 and 4.37GHz. Close agreement between the numerical and experimental data is found.
Therefore, the numerical model is valid for optimal design of the metamaterial structures.
Acknowledgement: This research received funding from Headquarters of University Advancement at National Cheng Kung University, which is sponsored by the Ministry of Education, Taiwan.
Frequency (GHz) S21(dB)
5 5.5 6 6.5 7 7.5 8 8.5
-70 -60 -50 -40 -30 -20 -10 0
No SRR SRR-2
No SRR SRR-1
6.5575GHz
Frequency (GHz)
S21(dB)
3 3.5 4 4.5 5 5.5 6
-60 -50 -40 -30 -20 -10 0
No SRR SRR-3
4.3725GHz
Frequency (GHz) S21(dB)
4 4.5 5 5.5 6
-70 -60 -50 -40 -30 -20 -10 0
No SRR SRR-1
L=5mm L=6mm L=7mm
5.435GHz
