This document describes the design and analysis of a spiral microstrip patch antenna for potential medical applications. Key points: - The antenna is designed to operate in the 2.4-2.45 GHz Industrial, Scientific and Medical frequency band for applications like telemedicine. - Electromagnetic simulations show the antenna resonates at 2.4 GHz with a return loss of -25 dB, bandwidth of 0.83%, and directivity of 1.95 dB. - The antenna has a compact size of 29mm x 21mm x 1.63mm, omni-directional radiation pattern suitable for on-body and off-body use, and narrow bandwidth required for medical applications. - Future work involves

1. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 05 | May 2019 www.irjet.net p-ISSN: 2395-0072
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Design & Analysis of Microstrip Antenna in Spiral Structure for
Medical Application
Mr.S.M.Dhiwar1, Mr.A.Y.Kazi2
1,2Electronics and Telecommunication Department, AISSMS COE Pune, Maharashtra, India
---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract :- This work belongs to, spiral micro strip patch
antenna using 2.4- 2.45 Ghz industrial scientific andmedical
frequency band (ISM). A spiral microstrip antenna having
29mm X 21mm X 1.63mm with single feed point, current
distribution in spiral shape and using FR04 material with
dielectric constant 4.4.
Key Words: Compact Microsrtip antenna, Medical
application, Spectrum band, Body tissue
1. INTRODUCTION
Now a days, in telecommunication field, there is main
application is ‘Telemedicine or wireless medicine’. This
technology provides medical information and service to
remote area patient. In India there is most need of specialist
doctors in rural area, because there is no good sufficient
medical facility in rural area. And also there is no facility of
proper road transport.
Some of the new technologies, in sensing, Medical imaging
and wireless data communication are allowingtelemedicine
to provide healthcare at a distance place.
After Studying the previous work in this area weunderstand
that there is two type of antennas which are used in medical
applications.Theseareimplantableantenna andantenna use
as external device.
Implanted antenna which is use to provide the information
from the body to external device and provide energy to
cancer treatment. [7]
As per US federal communication commission weusedMICS
band which is between (402-405Mhz)and(2.4-2.5Ghz)ISM
band which are used for Medical applications, Industrial
applications and Scientific applications. [3]
2.4 Ghz band meant for ISM applications for unlicensed
utilization of radio-LAN device. It has been also asked ETSI,
(the agency in-charge of creating telecommunication
standards in Europe) to formulated the standard and the
measurement method approvals.[2]
For the patients’ safety we emphasis on low power
consumption; electrical and electromagnetic properties of
the human tissue to transmit data with high performance,
technical and medical design factors form
biocompatibility.[6]
We studied many dipole antenna which have beenproposed
for medical implant communication applications,forpatient
monitoring system. Like slot dipole, loop antenna in which
use magnetic field and less affected by the body tissue
compared to dipole
At last we use light weight, small in size, less fabrication cost
microstrip patch antenna.
2. ANTENNA DESIGN SPECIFICATION
In this paper, operating frequency 2.4 Ghz, which is used
industrial and scientific operations and also this frequency
band is used for cordless phone , blue tooth devices, near
field communication device and wireless local area network
device.
After a thorough study of the following parametric
considerations; viz, the electrical length, dielectric constant,
strip width, coaxial feeding position and with spiral
structure patch design antenna. the antenna has been
designed and measured using EM software like HFSS.
A spiral microstrip patch antenna with dimension of L xW
mm2 is proposed. This antenna is fabricated on FR04
substrate with 4.4 dielectric constant (εr) which is easily
available in market. Dimension of patch antenna 30mm X
40mm X 1.63mm
RF spectrum allocation is harmonized on an international
level through the Radio-communication sector within the
International Telecommunication Union (ITU). It set
guidelines for designed ISM bands according to ITU Radio
Regulation in the affected area.

2. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 05 | May 2019 www.irjet.net p-ISSN: 2395-0072
© 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1664
Table-1 frequency allocation In ISM band and applications.
After referring previous papers about frequencyrange,their
international rules and regulation and previous parametric
study the following parameters have been selected
Table – 2 Characteristics of the designed microstrip
antenna
Dielectr
ic
constan
t(εr)
Thickn
ess(h)
Electric
al
length(L
e)
Length
(L)
(mm)
Width
(W)
Operatin
g
frequenc
y(fr)
4.4 1.63
mm
27.63 mm 29
mm
23.5
mm
2.4Ghz
Figure 1 Proposed antenna with dimension
Length Dimension(mm) Width Dimension(mm)
L1 29 W1 5
L2 27 W2 2
L3 27 W3 1
L4 27 W4 1
L5 27 W5 2
L6 27 W6 0.75
L7 27 W7 2.5
L8 27 W8 1.75
L9 27 W9 1
L10 23 W10 1.35
1.2 Result and discussion :-
Fig.1 shows the structure of antenna, which is designed for
operating frequency 2.4 Ghz (which is in the ISM band) and
same is simulated by the electromagnetic simulator High
frequency structure simulators(HFSS) software
The antenna resonate at the frequency at 2.4GhzwithinISM
band
Frequency
range
Center
frequency
Availability Licensed
users
902-928Mhz 915Mhz Region 2 only
(with some
exceptions)
Fixed
mobile
expect
aeronautica
l mobile &
radiolocatio
n service in
region 2
additional
amateur
service
2.4-2.5Ghz 2.45Ghz World wide Fixed
mobile,
radiolocatio
n, Amateur
& armature
satellite
service
5.725-
5.875Ghz
5.8Ghz World wide Fixed
mobile
,radiolocati
on, Amateur
& armature
satellite
service
24-24.25
Ghz
24.125Ghz World wide Amateur &
armature
satellite
Radiolocati
on & earth
exploration
satellite
service
61-61.5Ghz 61.25 GHz Subject local
acceptance
Fixed inter-
satellite
mobile &
radiolocatio
n service

3. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 05 | May 2019 www.irjet.net p-ISSN: 2395-0072
© 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1665
1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00
Freq[GHz]
-30.00
-25.00
-20.00
-15.00
-10.00
-5.00
0.00
dB(S(1,1))
HFSSDesign1XYPlot1 ANSOFT
CurveInfo
dB(S(1,1))
Setup1:Sweep
Fig- 2: Simulated return loss at 2.4Ghz in air enviorment
Figure 2 shows return loss of proposed antenna in air
environment, which is approximately -25dB at operating
frequency 2.4Ghz.
For medical applications we require a narrow bandwidth so
microstrip patch antennas are preferable. Calculated
bandwidth `is also so narrow, according to the simulation
result it is 0.83% for the ISM Band which is sufficient to
cover the desired frequency.
Due to the shape complexity of designed antenna, a small
mismatch appears in the real part of the input impedance
where it is 51.71Ω in the ISM band in the other hand the
imaginary part in zero at 2.4Ghz frequency.
1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00
Freq [GHz]
0.00
125.00
250.00
375.00
500.00
625.00
re(Z(1,1))
HFSSDesign1XYPlot12 ANSOFT
m1
Curve Info
re(Z(1,1))
Setup1 : Sweep
Name X Y
m1 2.4000 51.7189
Fig- 3a: Input Real impendance at 2.4Ghz
1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00
Freq [GHz]
-400.00
-200.00
0.00
200.00
400.00
600.00
800.00
im(Z(1,1))
HFSSDesign1XYPlot13 ANSOFT
Curve Info
im(Z(1,1))
Setup1 : Sweep
Fig- 3b: The imaginary impedance
1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00
Freq[GHz]
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
dB(VSWR(1))
HFSSDesign1XYPlot3 ANSOFT
CurveInfo
dB(VSWR(1))
Setup1:Sweep
Fig- 4: VSWR
Figure 4 shown that VSWR ≥ 1 at oprating frequncy 2.4 Ghz
Radiation pattern and gain in two dimensional plot which is
shown in figure 5a,5b.
Gain reduced at around 00 and 1800
-24.00
-18.00
-12.00
-6.00
90
60
30
0
-30
-60
-90
-120
-150
-180
150
120
HFSSDesign1Radiation Pattern 24 ANSOFT
m1
m2
m3
Curve Info
dB(GainTheta)
Setup1 : LastAdaptive
Freq='2.4GHz' Phi='0deg'
dB(GainTheta)
Setup1 : LastAdaptive
Freq='2.4GHz' Phi='10deg'
dB(GainTheta)
Setup1 : LastAdaptive
Freq='2.4GHz' Phi='20deg'
dB(GainTheta)
Setup1 : LastAdaptive
Freq='2.4GHz' Phi='30deg'
dB(GainTheta)
Setup1 : LastAdaptive
Freq='2.4GHz' Phi='40deg'
dB(GainTheta)
Setup1 : LastAdaptive
Freq='2.4GHz' Phi='50deg'
dB(GainTheta)
Name Theta Ang Mag
m1 360.0000 -0.0000 -1.8925
m2 300.0000 -60.0000 -6.0964
m3 340.0000 -20.0000 -2.4495
Fig-5a: Theta/degree Vs dB

4. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
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-30.00
-20.00
-10.00
0.00
90
60
30
0
-30
-60
-90
-120
-150
-180
150
120
HFSSDesign1Radiation Pattern 27 ANSOFT
m1m2
Curve Info
dB(DirPhi)
Setup1 : LastAdaptive
Name Phi Ang Mag
m1 90.0000 90.0000 2.8210
m2 270.0000 -90.0000 2.8210
Fig-5b : Phi/degree Vs dB
0.40
0.80
1.20
1.60
90
60
30
0
-30
-60
-90
-120
-150
-180
150
120
HFSSDesign1Radiation Pattern 5 ANSOFT
Curve Info
DirTotal
Setup1 : LastAdaptive
Freq='2.4GHz' Phi='0deg'
DirTotal
Setup1 : LastAdaptive
Freq='2.4GHz' Phi='10deg'
DirTotal
Setup1 : LastAdaptive
Freq='2.4GHz' Phi='20deg'
DirTotal
Setup1 : LastAdaptive
Freq='2.4GHz' Phi='30deg'
DirTotal
Setup1 : LastAdaptive
Freq='2.4GHz' Phi='40deg'
DirTotal
Setup1 : LastAdaptive
Freq='2.4GHz' Phi='50deg'
DirTotal
Setup1 : LastAdaptive
Fig-6: Directivity of antenna
Directivity of antenna which is shown in the figure 6a
Fig-6b : 3 Dimensional radiation pattern of directivity
Table-3 : Antanna radiation characteristics at resonance
frequency
Frequency Beam
width(0)
Maxium
directivity(dB)
2.4Ghz 850 1.95
CONCLUSIONS
In this work, we studied the proposed antenna by using the
EM simulated software HFSS, and getting the results of
proposed antenna parameters for medical applicationasper
study. The parameters we have seen, that antenna resonate
at the 2.4Ghz which is required as per ISM band and omni
directional radiation pattern required for on body and off
body application. In this we also have seen the radiation
pattern which is omni directional and narrow band width
which is required for medical applications. In this work we
have seen the band width is narrowapproximently160Mhz.
Expected directivity of antenna is atleast 1 and here we can
see directivity is approximetly 1. Required VSWR and
practicaly VSWR is also less than or equal to 1. So all this
parameters of this antenna are useful for medical
applications.
As future work we can implementthisantenna physicalyand
measure return loss in free space and also under skin of fish
body, antenna placed inside chicken and fish body changes
the dimension of antenna as small as possible .
REFERENCES
[1] C.A.BALANIS, Modern Antenna Handbook, Canada: A
JOHN WILEY & SONS,2008.
[2] Y.Benkler,”open Wireless vs Licensed Spectrum ;
Evidence from market adoption”,p.1.berkman center for
Internet and Society,2011.
[3] Report of the Unlicensed Device and Experimental
Licenses working Group,p.10. federal communication
commission.2002.
[4] Significance and utility of industrial ,Scientific and
medical band by Dr.Ranjit Sigh
[5] S.C.Survase and Vidya V. Deshmukh”Design of wearable
Antenna for telemedicine application “ international journal
of engineering Science and Innovative
Technology(IJESIT).vol2,no3,pp574-580,2013.
[6] Chia-Lin Chang, Fu-Jhuan Huang, Chien –Ming Lee and
Hong-Yi Huang, “Novel Triple-Band Biotelemetry System
with Miniaturized Antenna for Implantable Sensing
Application”,IEEE SENSORS Conference, vol.10,no.2,pp104-
107,2010.
[7] S.Ulah, P. Khan,N.Ullah,S.Saleem,H.HigginsandK.S.Kw,”A
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803,2009.
[8] A.Sabban “Wearable antennas formedical application”,in
Advancement in Microstrip Antennas with Recent
Applications, Crotia, InTech, March 2013,pp.305-335.