electromagnetic effect of rectangular spiral metamaterial

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© 2016 Chnar Aziz, open access article. Distributed under the terms of Creative Commons

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Journal of Modeling and Simulation of Antennas and Propagation, Vol. 2 (1), 13-21, 2016

ISSN: 2377-1674, Published online: www.unitedscholars.net/archive

Electromagnetic Effect of Rectangular Spiral

Metamaterial on Microstrip Patch Antenna

Performance

Chnar Hussein Aziz1

and Asaad M. J. Al-Hindawi2

1, 2 Communication Engineering Department, Sulaimani Polytechnic University, Sulaymaniyah, Iraq

[email protected] , [email protected]

ABSTRACT

This paper studies the electromagnetic effect, during

the process of covering metamaterials, on the

performance of a microstrip rectangular patch antenna

fed by a microstrip line for three ranges of operating

frequencies. The metamaterial cell is selected to be

double layers of rectangular spiral shape spaced by 1.5

mm FR4 epoxy substrate. The studied patches are

chosen to be three different sizes and designed to operate

at a resonance frequency of 2.4, 8.5 and 17 GHz

separately. Afterwards, each antenna is covered by

studied metamaterial cells of different numbers

according to the antenna area. The studied patch antenna

covered with metamaterial is simulated using a HFSS

simulator. The obtained results indicate that the effect of

the metamaterial cell leads to an increase in the number

of resonance frequencies for each patch antenna while

the band width of antenna patch of 8.5GHz increases to

44.64%.

Keywords: Microstrip patch antenna, Metamaterial,

Refractive index, Permittivity, Permeability.

1. INTRODUCTION

Today’s need for more multifunctional systems

yields to the necessity for small mobile terminals,

including cell phones, handheld portable wireless

equipment for internet connection, short- and long-

range communication devices, RFIDs (radio

frequency identification), etc. Similarly, small

equipment and devices used for data transmission

and navigation (GPS systems) require small

antennas. These applications and continuing growth

of wireless devices will continue to challenge the

community to create smaller and more

multifunctional antennas [1]. The development of a

4G to 5G wireless communication industry has

grown by orders of magnitude, fuelled by digital

and RF circuit fabrication improvements, new large

scale circuit integration, and other miniaturization

technologies which make portable radio equipment

smaller, cheaper, and more reliable [2].

New artificial materials, such as metamaterial, are

introduced to design microstrip antennas for

enhancing the performance and reducing the profile

[3]. Metamaterials (MTMs) are artificial media

characterized by constitutive parameters generally

not found in nature whose values can be engineered

to specified values. The first structure that has been

used to prove the existence of metamaterial was a

Split Ring Resonator SRR structure invented in

2001 by Shelby Smith and Schultz at the University

of California. SRR is a metallic ring with a split

introduced in its structure and works like an LC

resonant structure. These SRRs can be arranged in

an array to form a material that exhibits negative values

of both mu and epsilon and thus negative values of

the refractive index, n. This structure shows a

magnetic resonance at a particular frequency. The

position of this resonance frequency can be

changed by changing different geometrical

parameters of SRR [4].

Li B., Wu B., and Liang C.-H. (2006)

presented a new method to improve the gain of a

circular waveguide array antenna with metamaterial

structure. The electromagnetic characteristics of

metamaterial and circular waveguide antenna with

metamaterial structure are studied by using a

Aziz et al, Journal of Modeling and Simulation of Antennas and Propagation, ISSN: 2377-1674, Vol. 2 (1), 13-21, 2016

14

numerical simulation method. Furthermore, they

are compared with those of a conventional circular

waveguide antenna. The simulation and

experimental results show that this method is

effective and that metamaterial structures can

congregate the radiation energy. Therefore, the gain

of the antenna increases while the side lobe level

decreases [5].

C. Sabah and S. Uckun (2009) presented the

frequency behaviour, in detail, of the multilayer

structure comprised of double-negative (DNG) and

dielectric slabs. The multilayer structure consists of

N pieces DNG and dielectric slabs with different

material properties and thicknesses. The incident

electric field is assumed to be a monochromatic

plane wave with any arbitrary polarization. The

DNG layers are realized using the parameters of

Lorentz/Drude type metamaterials. The transfer

matrix method is used in the analysis to find the

characteristics of the reflected and transmitted

powers. Finally, the computations of the powers for

two structures are demonstrated in numerical

results, for the application to design efficient filters

at the microwave, millimetre wave, and optical

frequency regions [6].

AsitK.Panda and Ashutosh Mohanty(2011)

proposed a new conjugate omega shaped structure

for the realization of the left hand material. This

new metamaterial (MTM) is designed and

simulated using CST MWS. The effective

permittivity & permeability are extracted from the

transmission & reflection data obtained by the

normal incident on the purposed structure. It is

shown that the purposed MTM exhibits DNG

material property and a negative refractive index in

a dual transmission band with a wider band in

frequency ranges of 3.35-6.37GHz and 12.53-

16.7GHZ. The conjugate omegas structures are

pseudo-chiral in nature, where both electric

magnetic polarization are due to induced electric

and magnetic fields [7].

P.K. Singhal and BimalGarg (2012) proposed

an “Interconnected Circular SRR’s” shaped

metamaterial structure at a height of 3.2mm from

the ground plane. The proposed metamaterial

structure enhances bandwidth by 173%, reduces

average area by 40%, increases directivity by

1.068dBi and reduces return loss by 16.513dB. The

proposed metamaterial structure along with the

patch antenna exhibits a 33.293dB return loss at

2.37GHz operating frequency and has an

impedance bandwidth from 2.3887 to 2.3118GHz.

The design and optimization of the Rectangular

micro strip patch antenna (RMPA) with and

without proposed metamaterial structure were

carried using CST Microwave Studio. Double-

Negative (permittivity and permeability) properties

of the proposed metamaterial structure have also

been verified in this work by using the Nicolson-

Ross-Weir (NRW) approach [8]

Mimi A. W. Nordin , Mohammad T. Islam ,

and Norbahiah Misran(2013) proposed a new

compact ultra wide band (UWB) patch antenna

based on the resonance mechanism of a composite

right/left-handed (CRLH) transmission line (TL).

The radiating element of the antenna is made from

three left-handed (LH) metamaterial (MTM) unit

cells placed along one axis. Each unit cell combines

a modified split-ring resonator (SRR) structure with

capacitively loaded strips (CLS) [9].

Wei Liu and etal (2014) presented a

metamaterial-based broadband low-profile

mushroom antenna [10]. The proposed antenna is

formed using an array of mushroom cells and a

ground plane and feed by a microstrip line through

a slot cut onto the ground plane. The proposed

dielectric-filled ( =3.38) mushroom antenna with

a low profile of 0.06λ0 (λ0 is the operating

wavelength in free space) and a ground plane of

1.10λ0×1.10λ0, attains 25% measured bandwidth

with (|S11<-10dB|) 9.9dBi average gain at 5-GHz

band.

The present paper introduces a study of the

electromagnetic response of metamterial cells on

the performance of a microstrip rectangular patch

antenna (band width and radiation pattern). Three

frequency bands of operating frequencies 2.4, 8.5


15

and 17GHz have been chosen to test the designed

antennas.

2. ANTENNA DESIGN

Microstrip Patch Antenna Structure

The configuration of the studied patch antenna

illustrated in Figure 1, is feed by a microstripline

and is of rectangular shape. Three microstrip patch

antennas are designed separately to operate at 2.4,

8.5 and 17GHz and their dimensions are shown in

Tables 1, 2 and 3 respectively. The substrate

material is chosen to be Rogers RT/duroid 5880

with epsilon=2.2. The frequency responses of the

designed patch antennas to the return losses are

plotted in figures 2, 3 and 4 respectively.

Fig.1: Rectangular edge –feed patch antenna structure.

Table (3): Calculated dimensions of edge–feed rectangular

patch antenna at 17GHz.

Fig. 2: S11 parameter for the designed patch antenna at 2.4GHz.

Element Value (mm)

Patch dimension along x 15

Patch dimension along y 10.5

Substrate thickness 1.5748

Substrate dimension along x 25

Substrate dimension along y 32.5

Ground dimension along x 25

Ground dimension along y 32.5

Edge feed width 1

Edge feed length 7

Feed width 6

Feed length 11

Fig.1: Structure of edge–feed rectangular patch antenna.

Table 1: Calculated dimensions of edge–feed

rectangular patch antenna at 2.4 GHz.

Element Value ( mm)

Patch dimension along x 49.41



Substrate dimension along x 83.6


Ground dimension along x 83.6


Edge feed width 1.885

Edge feed length 23.418

Feed width 4.852

Feed length 38.075

Table 2: Calculated dimensions of edge–feed

rectangular patch antenna at 8.5GHz.

Element Value (mm)

Patch dimension along x 6.9756



Substrate dimension along x 16.4244


Ground dimension along x 16.4244


Edge feed width 1.2731

Edge feed length 3.336

Feed width 4.3460

Feed length 1.3908


16

Structure of metamaterial unit cell

The designed structure of the metamaterial unit

cell is rectangular double spiral rings. It is

simulated using HFSS simulation tool and the

simulation results are calculated. The simulation

setup used for HFSS computations is described in

figure 5, where the unit cell of metamaterial is

surrounded by an air medium and the z polarized

incident electromagnetic plane wave propagates

along the y direction.

Hence, the direction of the magnetic field vector

is along the x axis and this is perpendicular to the

resonator plane. Perfect Electric Conductor (PEC)

boundary conditions are applied along the

boundaries perpendicular to the z-axis and the

Perfect Magnetic Conductor (PMC) boundary

conditions are applied along the boundaries

perpendicular to the x-axis. The remaining two

boundaries are assigned to be the input-output wave

ports, as seen in Figure 5.

The simulated spectra for transmission and

reflection is shown. Characteristics of the

proposed structure were found as a result of

simulation using HFSS in order to analyse and

calculate the effective permittivity and

permeability and then effective refractive index

of the new material using Nicolson Ross-Weir

(NRW) approach [11][12][13] as follows:

(1)

(2)

(3)

Where represents a free-space wave number and

and is substrate thickness between the spirals

rings.

Table 4 shows the dimensions of the proposed unit

cell metamaterial while figure 6 describes the

structure of the unit cell of metamaterial.

Fig. 6: Proposed unit cell of metamaterial structure.

Fig. 5: Setup for HFSS simulations.

Fig. 4: S11 parameter for the designed patch antenna at

17GHz.

Fig. 3: S11 parameter for the designed patch antenna at

8.5GHz.

Table 4: Dimensions of unit cell metamaterial.

Metamaterial

elements

Width

(mm)

Length

L(mm)

Thickness

h(mm)

Space

between

turns

(mm)

Material

The most

outer Ring 4.4 4.4 0.03 ------- Copper

Substrate 5 5 1.5 ------- FR4_epoxy

Spiral 0.4 ------- 0.03 ------- Copper

Turns ------- ------- ------- 0.1 Copper


17

The simulated spectra for transmission (S21) is

shown.

The simulated spectra for transmission (S21) and reflection (S11) characteristics of the proposed

metamaterial structure are given in Figure 7. In

figure 7, blue and red lines indicate the magnitude

of S21 and S11 respectively. It is clear from the

figure that the structure resonates at ten different

frequencies during the range (1-20) GHz.

Figure 8 shows the retrieved effective

permittivity and permeability of the metamaterial

unit cell using matlab codes. From the figure 8,

simultaneous negative permeability and negative

permittivity occur during the range (1-20) GHz

except for small frequency ranges.

Figure 9 shows the negative refractive index of

the metamaterial unit cell using matlab codes. From

the figure 9, the negative refractive index occurs

during the range (1-20) GHz except for small

frequency ranges.

4. RESULTS AND DISCUSSION

The studied patch antennas are covered by a

different number of metamaterial cells and the

simulated results are explained as follows.

1. Microstrip patch antenna of resonance frequency

2.4GHz covered by 99 cells of metamaterial

according to patch area.

Figure 10 shows the return loss characteristics,

S11, of a metamaterial cover patch antenna. From the

Figure 10 and in comparison with S11 of ordinary

patch antenna, figure 2 concludes that there is a

down shift and increase in the number of resonant

frequency during (1-5) GHz range of frequency.

Fig.7: HFSS predicted scattering parameters S11 and S21for

the unit cell of proposed metamaterial.

Fig. 8: Evolution of real part of permeability and

permittivity according to the frequency.

Fig. 9: Evolution of real part of refractive index according

to the frequency.

Fig.10: Return loss characteristics for the patch antenna

covered by metamaterial at 2.4GHz.


18


8.5GHz covered by 35 cells of metamaterial.

Figure 11 shows the return loss characteristics of a

metamaterial covered patch antenna.

Fig. 11: Return loss characteristics for the patch antenna

covered by metamaterial at 8.5GHz

From the figure 11 and in comparison with S11 of

the ordinary patch antenna in Figure 3, it is

concluded that there is an increase in band width.

The bandwidth of the antennas is from (8.98-14.14)

GHz and the resultant percentage is 44.64% with

respect to center frequency.


17GHz covered by 20 cells of metamaterial.

Figure 12 shows the return loss S11 characteristics

of a metamaterial cover patch antenna. From the

Figure 12 and in comparison with S11 of ordinary

patch antenna Figure 4, it is concluded that there is

an increase in the number of resonant frequencies.

4. The effect of metameterial cells on radiation

pattern and antenna gain is studied and is shown in

the following figures (13,14 and 15). It is clear that

this increases the lobbing in antenna radiation

pattern.

Figure (13-a) shows the radiation pattern and

gain of an ordinary patch antenna with a resonant

frequency of 2.4 GHz. Figure (13-b), figure (13-c)

and figure (13-d) show the radiation pattern and

gain of an ordinary patch antenna with 99 MTM

cells for three different resonant frequencies (2.12,

3.52, 4.40) GHz respectively. The antenna gain

increases at the frequencies 2.12 and 3.52 GHz.

Figure (14-a) shows the gain of an ordinary

patch antenna with a resonant frequency of 8.5 GHz

and the best three gains when the antenna is

covered with 35 MTM cells for three different

resonant frequencies (10.06, 11.5, 12.34 GHz) as

shown in figure (14-b), figure (14-c) and figure (14-

d) respectively. On the contrary, the antenna gain

decreases.

Figure (15-a) shows the gain of an ordinary patch

antenna with a resonant frequency of 17 GHz and

the three best gains achieved when the antenna is

covered with 20 MTM cells for three different

resonant frequencies (14.96, 21.08, 23.12 GHz) as

shown in figure (15-b), figure (15-c) and figure (15-

d) respectively. Here, the gain is also decreased.

Figure 13-a: Antenna alone at 2.4GHz.

Figure 13-b: Antenna covered with 99 MTM cells at

2.12GHz.

Fig. 12: Return loss characteristics for the patch antenna

covered by metamaterial at 17GHz.


19

Figure 13-c: Antenna covered with 99 MTM cells at

3.52GHz.

Figure 13-d: Antenna covered with 99 MTM cells at

4.4GHz.

Figure 14-a: Antenna alone at 8.5GHz.

Figure 14-b: Antenna covered with 35 MTM cells at

10.06GHz.

Figure14-c: Antenna covered with 35 MTM cells at

11.5GHz.


12.43GHz.

Figure 15-b: Antenna covered with 20 MTM cells

at 14.96GHZ.

Figure 15-a: Antenna alone at 17GHZ.


20

5. CONCLUSION

This paper studies the electromagnetic response

of metamaterial cells on the performance of a

microstrip patch antenna (band width and radiation

pattern). Three frequency bands of 2.4, 8.5 and

17GHz have been chosen to test the designed

antennas. The simulated results indicate that the

studied rectangular patch antennas covered by

different metamaterial cells resonate with multiple

resonant frequencies except for the case of the

patch reading 8.5GHz. The bandwidth increases to

44.64%. The radiation pattern of the antenna is

divided into multiple lobes and leads to a decrease

in antenna gain except for the case of the patch

operating at a low frequency of 2.4GHz.

REFERENCES

[1] John Volakis, Chi-Chih Chen, and Kyohei

Fujimoto, "Small Antennas: Miniaturization

Techniques & Applications", United States, 2010.

[2] Punit S. Nakar, "Design of a compact

Microstrip Patch Antenna for use in

Wireless/Cellular Devices", Master Thesis,

Florida State University, Florida, United States,

2004.

[3] R. Khajeh Mohammad Lou, T. Aribi, and Ch.

Ghobadi , "Improvement of Characteristics of

Microstrip Antenna Using of Metamaterial

Superstrate" , 1st International Conference on

Communications Engineering , University of Sistan

and Baluchestan , pp.126 -129, 2010.

[4] Andrew A. Houck, Jeffrey B. Brock, and Isaac

L. Chuang , "Experimental Observations of a Left-

Handed Material That Obeys Snell’s Law, Physical

Review Letters", Vol. 90, No. 13, pp. 1-4, 2003.

[5] Li B., Wu B., and Liang C.-H , "Study on High

Gain Circular Waveguide Array Antenna With

Metamaterial Structure", Progress In

Electromagnetics Research, PIER 60, pp. 207–219,

2006.

[6] C. Sabah, and S. Uckun, "Multilayer System

Of Lorentz/Drude Type Metamaterials with

Dielectric Slabs And Its Application To

Electromagnetic Filters" , Progress In

Electromagnetics Research, PIER 91, pp 349–364,

2009.

[7] Asit K.Panda, and Ashutosh Mohanty,

"Realization Of A Dual Transmission Band

Conjugate Omega Shaped Metamaterial" , IJCSI

International Journal of Computer Science Issues,

Vol. 8, Issue 6, No 2, pp.175-179, 2011.

[8] P.K. Singhal1,and Bimal Garg , "A Novel

Approach For Size Reduction Of Rectangular

Microstrip Patch Antenna" , IJECCT 2012, Vol. 3

.No.1, pp. 35-39, 2012.

[9] Mimi A. W. Nordin, Mohammad T. Islam, and

Norbahiah Misran, "Design Of A Compact

Ultrawide band Meta- Material Antenna Based On

The Modified Split-Ring Resonator And

Capacitively Loaded Strips Unit Cell", Progress In

Electromagnetics Research, Vol. 136,pp. 157-173,

2013.

[10] Wei Liu, ZhiNing Chen and Xianming Qing ,

"Metamaterial-Based Low-Profile Broadband

Figure 15-c: Antenna covered with 20 MTM cells at

21.08GHz.


23.12GHz.


21

Mushroom Antenna" , IEEE Transactions on

Antennas and Propagation , Vol. 62, Issue: 3,

2014 .

[11] J. G. Joshi,Shyam S.Pattnaik,Swapna Devi and

M. R.Lohokare , "Electricaly Small Patch Antenna

Loaded With Metamaterial", IETE Journal of

Research, Vol. 56, Issue 6, PP. 373-379, 2010.

[12] T. Aribi, R. Khajeh Mohammad Lou, and

Ch.Ghobadi , "Enhancement Gain of Rectangular

waveguide Antenna by Electromagnetic

Metamaterial" , 1st International Conference on

Communication Engineering, University of Sistan

and Baluchestan, PP. 122 -125, 2010.

[13]http://www.elenasaenz.com/pfc/memoria/13_a

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electromagnetic effect of rectangular spiral metamaterial

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