Design of Miniaturized Meta material circular Patch ...proposed antenna have achieved better gain...

Design of Miniaturized Meta material circular Patch Antennas for Bio

Medical Applications

C. Keerthi* Student, M.Tech (CMS), Dept. of ECE, SVEC,

Tirupati.

E-mail ID: [email protected]

Mobile No: 9492774615

G. Guru Prasad** Asst Professor, Dept. of ECE, SVEC, Tirupati.

Mobile No: 9492657579


R. Nagendra*** Asst Professor, Dept. of ECE, SVEC, Tirupati.


Mobile No: 9949632049

S. Mehtaj Begum**** Asst Professor, Dept. of ECE, SVEC, Tirupati.

Abstract—Communications technology and

biomedical sensors offer services for the patient’s

vital signs to be monitor outside the clinical

environment. The demand for the implantable

telecommunication devices in medical applications

has been growing very rapidly over the past

decade. Microwave antennas and biomedical

sensors are the major components of telemetry

systems linked to medical applications. Meta

materials are artificial structures, and their

electromagnetic properties does not present in

nature. Employing Meta materials in micro strip

antenna substrate will result in the improvement

of the antenna parameters like bandwidth, gain,

efficiency, etc. A novel design of Meta material is

considered in order to miniaturize a circular

micro strip patch antenna. Meta material is

composed of two nested split Hexagons and it is

located on a 10x10mm Rogers RT/duroid 5880

substrate with 0.7874mm thickness and dielectric

constant value is 2.2. Here 2x2 array of such

nested split Hexagons is placed on the patch

antenna substrate. By using the Meta material in

the antenna structure, the dimension of this

proposed antenna is reduced to half compared to

a micro strip patch antenna. Here the circular

patch antennas loaded by an in homogeneous

substrate partially filled with a negative Meta

material is preferred because it supports a

resounding radiating mode, even if the total size of

the radiator is significantly smaller than the

wavelength of operation.

Here HFSS Software is used for simulation.

Keywords: Antenna, Meta material, Circular Micro

strip antenna, Rogers RT/ duroid 5880, HFSS

software.

I.INTRODUCTION

Now a days, the demand for the deployment of

wireless telemetry systems in medicine has

significantly increased due to necessity for early

diagnosis of diseases and continuous monitoring of

physiological parameters. Microwave antennas and

sensors are key components of these telemetry

systems since they provide the communication

between the patient and base station. An antenna is a

transmitter which converts electrical signal into

electromagnetic waves and also it radiates into the

space. The micro strip antenna have many features

like low weight, light cost, low profile etc; It has both

advantages and disadvantages, one of the

disadvantage is narrow bandwidth. The micro strip

International Journal of Applied Engineering Research ISSN 0973-4562 Volume 12, Number 1 (2017) © Research India Publications. http://www.ripublication.com

236

mailto:[email protected]



antennas used in many applications like-Satellite

Communications, Remote Sensing and Biomedical

etc;

Now a day’s small size antenna plays an

important role in many aspects like mobile phones

etc; there are several techniques to miniaturize the

size of an antenna with high dielectric substrate,

DGS, slotted and meandering techniques. In this

paper, the size of antenna is miniaturized with Meta

material approach.

Meta materials (Meta means “beyond” in

Greek) usually gain their properties from structure

rather than composition. Here all natural materials

are glass, diamond and it is having both positive

electric permittivity (∈) and magnetic permeability

(µ) with this we can’t reduce the size of an antenna

because of that we are using meta material it has both

negative electric permittivity (∈) and magnetic

permeability (µ).The periodic array of copper wires

with specific radius and spacing produces negative

electric permittivity (∈).Periodic array of split ring

resonator having negative µ. The Meta material was

fabricated by interleaving SRR and copper wires.

Meta materials a new design methodology

and it is mainly used in medical applications like

diagnosis of cancer cells, Cancer treatment, patient

monitoring, brain signal analysis, body temperature,

blood pressure monitoring etc.; Here, 2x2 array

hexagonal shape split ring resonator slots on

dielectric substrate, which acts as a Meta material and

it is placed at ground to reduce the back wave

propagation which harms patient body tissues. The

Hexagonal split ring resonator slots placed in

dielectric substrate, and then it acts as Meta material

antenna is shown in figure 1.

Figure 1: Meta material Antenna.

II. DESIGN SPECIFICATIONS

To design a rectangular patch antenna using

transmission line model we need frequency=2.4GHz,

Dielectricconstant (∈𝑟 ) =2.2, Height of

substrate=0.7874mm.

1. Width of the Patch

W=𝐶

2𝑓 ∈𝑟+1

2

=48.402mm.

Where, C=Free space velocity of light.

= 3x1010𝑐𝑚.

∈𝑟= Dielectric constant of substrate.

2. Effective dielectric constant of the rectangular

micro strip patch antenna (∈𝑟 )

∈𝑒𝑓𝑓= ∈𝑟+1

2+∈𝑟−1

2[1 + 12

𝑕

𝑤]−1

2 = 2.31.

3. Effective length (𝐿𝑒𝑓𝑓 )

𝐿𝑒𝑓𝑓=𝐶

2𝑓0 ∈𝑒𝑓𝑓

= 40.220mm.

4. Actual length of the patch (L)

L=𝐿𝑒𝑓𝑓 -2𝛥𝐿 = 39.0246mm.

5. Calculation of Length Extension

𝛥𝐿

𝑕=0.412

(∈𝑒𝑓𝑓 +0.3)

(∈𝑒𝑓𝑓 −0.258)x

(𝑤

𝑕+0.264)

(𝑤

𝑕+0.8)

= 0.51913.

Ground plate calculations:

1. Length (𝐿𝑔 ) = 6h+L=0.220mm.

2. Width (W) =6h+W=53.1264.


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Feed point location(x):

Here coaxial probe feeding technique is used

𝑅𝑖𝑛=𝑅𝑒𝑠𝑖𝑛2(𝜋𝑥

𝐿)

𝑅𝑖𝑛 =Input impedance 50Ω

𝑅𝑒=1

2(𝐺𝑠+𝐺𝑚 )

𝐺𝑠=Slot Conductance

𝐺𝑚=Mutual Conductance

𝑅𝑒=200Ω (approx 199Ω)

X =6.70mm.

III. ANALYSIS OF RECTANGULAR AND

CIRCULAR MICRO STRIP PATCHES

ANTENNA AND META MATERIAL

STRUCTURE ANTENNA:

The Rectangular Micro strip Patch Antenna is

designed on Rogers 5880 substrate. Parameters

specifications of rectangular micro strip patch

antenna are shown above.

(i) Design of Rectangular Patch Antenna

HFSS Software is used to design and simulate Patch

antenna. The designed rectangular patch antenna

with probe feed is shown in figure 2.

Figure 2: Designed Rectangular Patch Antenna.

(ii) Design of circular Patch Antenna

Circular patch dimensions are obtained by

considering the half of the diagonal length of

rectangular patch. The designed circular patch

antenna with probe feed is shown in figure 3. The

radius of patch is 20 mm.

Figure 3: Designed Circular Patch Antenna.

(iii) Design of circular Patch Antenna using

Hexagonal shape split ring resonator:

Calculations of Hexagon dimensions: Dimensions of hexagonal shape split ring resonator is

calculated by using the formulas shown below

Designed 2x2 array of circular patch antenna is shown in figure4.

Radius (a) =1+1

49log[

(𝑤

𝑕)2+(

𝑤

52𝑕)2

(𝑤

𝑕)4 +0.432

]+1

18,7log[1+

(𝑤

𝑕∗

1

18.1)3 = 1.0527𝑚𝑚.

𝑎𝑒=a 1-2𝑕

𝜋𝑎∈𝑟 (ln

𝜋𝑎

2𝑕+ 1.7726)0.5=1.05mm

𝜋𝑎𝑒2=

33

2𝑠2=Side of the patch=1.1546mm.

By using 2x2 array hexagonal shape split ring

resonator slots on dielectric substrate, which acts as

Meta material, the size of antenna is reduced to half.

Figure 4: Designed Circular Patch Antenna using Meta material.

IV.SIMULATED RESULTS

(i) Rectangular Patch Antenna

Return loss: After simulation, the return loss of

Rectangular patch antenna is shown in figure 5.At

2.4GHz, obtained return loss is -31dB,

Bandwidth=150MHz .


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Figure 5: Return loss for Rectangular Patch.

Gain: The simulated gain of the Rectangular patch antenna is 7dBi is shown in Figure 6.

Figure6:Gain of Rectangular Patch Antenna

(ii) Circular Patch Antenna




Bandwidth=150MHz.

Figure7:Return loss of Circular Patch Antenna.

Gain: The simulated gain of the Rectangular patch

antenna is 7dBi is shown in Figure 8.

Figure 8: Gain of Circular Patch Antenna.

(iii) Circular patch with Meta material:




Bandwidth=150MHz.

Figure 9: Return loss of Meta material antenna.

Gain: The simulated gain of the Rectangular patch antenna is 6dBi is shown in Figure 10.

Figure 10: Gain of Meta material antenna.

The results obtained for both Antennas with and

without Meta materials are compared in table 1.

Table 1: Comparison of Results

Size Operating

frequency

Bandwidth Gain

Circular

patch

20mm

2.4GHz

150MHz

7dBi

Meta

material

antenna

10mm

2.4GHz

150MHz

6dBi

CONCLUSION AND FUTURE SCOPE

Conclusion

Hexagonal 2x2 array patch antenna is designed and

simulated using HFSS software and different


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parameters like return loss, gain are determined at

2.4GHz frequency band. By using Meta material in

antenna design the size of antenna is reduced. The

proposed antenna have achieved better gain and

satisfied return loss. The simulated results show that

the obtained impedance bandwidth 150MHz. So,

these antennas can be used in biomedical

applications. Project main aim is to miniaturize the

size of an antenna times and it is reduced by

cutting dielectric with hexagonal shape of split ring

resonator and then it acted as a Meta material and it

reduced the size to half.

Future Scope

The gain of the antenna can be additionally increased

by designing higher order 4x4 array hexagonal shape

split ring resonator slots on dielectric substrate,

which acts as Meta material, the size of antenna can

be reduced and increase the parameters like gain,

return loss ,bandwidth. In present work Micro strip

patch antenna designed using Rogers’s 5800

substrate. In future reduce the size of an antenna for

better results.

V. REFERENCES

[1] Arul Kumar, Nithin Kumar and Dr. S. C,

Guptha,” Review On Micro strip Patch

Antenna Using Meta material”, International

Journal of Engineering Research and General

Science Volume 2,Issue 4,July,2014.

[2] LJ.XU, Y.X. Guo, Wu,”Miniaturized

Circularly Polarized Loop Antenna for

Biomedical applications’, IEEE Trans. On

Antennas and Propagate, vol. 63, no.

3,pp.922-930,Mar-2015.

[3] N. Ripin, W.M.A.W. Saidy, A.A. Sulaiman,

N.E.A. Rashid and M.F Hussin,

”Miniaturization of micro strip patch antenna

through meta material approach”, 2013 IEEE

Student Conference on Research and

Development (SCOReD), pp.365-369.2013.

[4] Y.Dong, H.Toyao and T.Itoh, ”Design and

Characterization of Miniaturized Patch

Antennas Loaded with Complementatory

Split -Ring Resonators”, IEEE Transactions

on Antennas and propagation, vol.60,no.

2,pp.772-785, February 2012.

[5] Vikas Guptha and B.S.Dhaliwal,

“Performance Enhancement of Rectangular

Micro strip patch antenna loading

complementatory Split-Ring Resonator in the

patch”, International Journal of Electronics

Engineering, Noida, 2012.

[6] H. Nornnikman, B.H.Ahmad, “Effect of

Single on Micro strip Patch Antenna

Design”, IEEE Symposium on Wireless

Technology and Applications (Iswta),

Bandung, Indonesia,2012.

[7] Ankit Samadhiya, Rahul Dev Varma,”

Design of SSRR based Meta material

Design of SSRR based Meta material in

Patch Antenna Parameters with Negative µ

and ∈ ",International Conference on

Electronic Communication &

Instrumentation, Jhansi UP ,6-7 April2012.

[8] A. Dhouibi, S. N. Burokur and A. Lautrec,

Compact Meta material-Based Substrate-

Integrated Luneburg Lens Antenna,” IEEE

Antennas and Wireless Propagation Letters,

Vol. 11,pp. 1504-1507, 2012.


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Brief profile about Ms. C. Keerthi

Ms. C. Keerthi Received B.Tech degree in

Electronics and Communication Engineering from

SCSVMV, Kancheepuram in the year 2015 and

M.Tech in Communication Systems from Sri

Vidyanikethan Engineering College, Tirupati in the

year 2017.

Brief Profile about Mr. G. Guru Prasad.

Mr. G. Guru Prasad Received B.Tech degree in

Electronics and Communication Engineering from

JNTUH, Hyderabad in the year 2008 and M.Tech in

Electronics Instrumentation and Communication

Systems from Sri Venkateswara University, Tirupati

in the year 2010. He worked as Transmission

Engineer at ERICSSON India Pvt. Ltd, Bangalore.

He worked with Ericsson 2G/3G GSM network

equipments and did number of Airtel projects like

Migration from Classic node to Traffic node, AXX

and HICAP using Mini Link software and done

projects like connecting new Micro wave links

usingTraffic and Classic Nodes. He is Zonal Head for

4 districts in north Karnataka like Davanagere, Hobli,

Bellari, Gadag and Haveri.

He designed 8x8 Micro strip Patch Antenna

Array for Winf Profiler Radar, operating at 430 MHz

at National Atmospheric Research Laboratory,

Gadanki, Department of Space, and ISRO. This

Radar has been installed at Cochin, Kerala for

weather forecast.

He is presently working as Assistant

Professor in department of ECE since 2011. He

published more than 12 papers in reputed

international journals. Presented 2 papers in IEEE

international conferences and 5 papers in National

conferences. His Research areas of interest are design

and simulation of Multi-band Antennas, Electrically

small Antennas, Image and Video Processing,

communication Networks.

Brief Profile about Mr. R. Nagendra.

R. Nagendra working as Assistant professor in the

department of ECE, SVEC, He did his PG in Digital

Systems and Communication Engineering from NIT

Calicut. He is pursuing Ph. D., in S.V University,

Tirupati. His area of specialization is Wireless

Communications.


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Design of Miniaturized Meta material circular Patch ...proposed antenna have achieved better gain...

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