Design of Tripple Band Microstrip Patch Antenna Array with Mutual ...

ISSN 2249-6343
International Journal of Computer Technology and Electronics Engineering
(IJCTEE) Volume 3, Issue 2, April 2013
Design of Tripple Band Microstrip Patch
Antenna Array with Mutual Coupling
Deepak Sawle , Prof. Rajesh Nema
Abstract— Microstrip Patch antenna are very usefull in
communication system .Microstrip patch antenna are
advantages for various applications performances with their
low Weight, low profile, low cost , made them the perfect and
easy to design . Its has some disadvantages such as narrow
bandwidth , Low gain and directivity to overcome with these
issues array is designed . The resonant frequency for proposed
design is 3GHz. This proposed design perfomed in the three
frequency band L-band, S-ban d and C-band at frequencies of
1.9GHz, 3.5GHz,and 5.4GHz. The return loss in all three band
is more than -10dB . All this three band cover the following
GSM, WiMAX, WLAN applications in this proposed geometry
designing . Calculations and simulation is performed with
Zeland Program manager IE3D Software . The return loss ,
VSWR , radiating efficiency , bandwidth and radiating
patterns are evaluated . With IE3D simulation Software
proposed antenna is designed and simulated.
Keywords— Microstrip patch , Slot , Mutual coupling
Antenna array , Ie3d .
I . INTRODUCTION
In the recent years with the rapid development in the modern
technology communication system is used with various
applications in these technologies. In the communication
systems requires the low cost, low profile antenna with high
gain and directivity. For these performances are not possible
with single microstrip patch antenna for this phased array[2]
has been designed with two or more than two element are
linear , collinear or corporate feed . I have used linear
feeding in my design with active element pattern array with
mutual coupling effect [3]. It is necessary to consider mutual
coupling in antenna array because of its important effects on
results. The proposed microstrip array is design with
considering active patch and passive patches in linear feed .
Manuscript received April , 2013.
Deepak Sawle is currently pursuing masters degree program in
electronics and communication engineering in NIIST bhopal , RGPV
University , INDIA, PH-+919993774648 E-mail: deep_
sawle@yahoo.com
Prof. Rajesh Nema is currently professor in electronics and
communication engineering in NIIST Bhopal, RGPV University,
INDIA, PH-+919893216819
E-mail: rajeshnema2010@rediffmail.com
linear feeding . The mutual coupling effect [5] is considered
for my design and spacing between elements is λ/4 for my
design . Because of mutual coupling scanning , error of
beam forming , and side lobe level are effected to reduces
this effect in array design electromagnetic band gap
(EBG)[4] and defected ground plane (DGP) is used in my
proposed design. So that here in this proposed design mutual
coupling effect is considered.
II. DESIGN SPECIFICATIONS
The Microstrip patch antenna parameters for rectangular
geometry are calculated from the formulas given below[1].
Calculation of the Width (W)
The first step is to find the width , W of the patch at the
resonant frequency using Equation 1 ;
c 2
w= 2f ε +1
(1)
Where
o
r
ε r = the relative permittivity of the substrate
c = the speed of the light in free space
f o = the resonant frequency
The ε eff, effective dielectric constant equation is given by
Equation (2).
ε +1 ε -1
h
2 2 w
r r
ε = + 1+12
eff
The actual length of the patch is calculated by Equation 3;
L=L - 2ΔL
eff (3)
1 -
2
(2)
37

ISSN 2249-6343
International Journal of Computer Technology and Electronics Engineering
(IJCTEE) Volume 3, Issue 2, April 2013
To measure for the fringing effects , the actual length of the
patch also includes the correction factor due to fringing
effect . The effective length is given by Equation 4 ;
L =
eff
(4)
2f ε
r
c
eff
Correction factor can be found using equation 5.
w
(ε +0.3)( +0.264)
eff
ΔL
=0.412
h
h
w
(ε -0.258)( +0.8)
eff
h
Where, h = Height of the substrate .
Ground patch of the geometry is design with the following
equation 6 ;
Length of ground patch
(5)
The rectangular microstrip patch antenna of single element is
design with the calculated parameters geometry is designed
with spacing between center element and rest two elements is
λ /4 (λ is the free-space wavelength at the operating frequency
) . This proposed geometry is designed in symmetric pattern
with linear feed elements . The concept used in proposed
designed is to used active patch element in array design so
that the array size will be reduced and simulation will be
realized easily with limited feedings in phased array antenna
design .The designed geometry is composed with single
active element centered with two passive elements are feeded
linearly shown in figure 2. The simple Microstrip substrate
FR-4 with dielectric constant 4.3 and loss tangent 0.019 is
used for my design . The radiating patchwith ring shaped slot
is designed and the ground plane with two parallel rectangular
slots . The probe is given on centered patch at (0, -10.5), so
the mutual couple and current distribution on both passive
patched shoulb be equale because of symmetrical elements .
When the current on active and passive patches are same so
the higher broadside gain can be achive in phase scaning of
proposed array .
L g = 6h+L
(6.a)
Width of ground patch
W g = 6h+w
(6.b)
The evaluated parameters are given in table 1.
Width = 30.72mm
mm3333030.72
Antenna parameters
Resonant frequency f r
Dimensions
3GHz
Dielectric constant ε r 4.3
Length = 23.74mm
Height of Substrate (h)
Width (W)
Length (L)
1.5mm
30.72mm
23.74mm
Fig.1.The proposed single Microstrip patch antenna
Effective Length L eff 25.12
Effective dielectric substrate ε eff 3.96
Widht of ground patch W g
Length of ground patch L g
32.74mm
39.72mm
Free space wavelength λ 100
Fig.2.Geometry of Proposed Antenna Array design
38

ISSN 2249-6343
International Journal of Computer Technology and Electronics Engineering
(IJCTEE) Volume 3, Issue 2, April 2013
III. SIMULATION AND RESULTS
The proposed design geometry with probe feeding is given at
(0, -10.5) , geometry of microstrip phased array antenna
designed with IE3D and simulation is perfomed . At the
resonant frequency of 3GHz the design is simulated in the
frequency range of 1 to 6GHz.The simulated return losses
versus frequency for the array exhibits in fig.3.The return
losses at three frequency bands are -19.8dB at 1.9 GHz , -
23.19 dB at 3.5 GHz, and 25.45 dB at 5.4GHz (over than -
10dB in all frequency bands ). The three frequency bands
which cover GSM band , LTE (long term evalution ) in 4G ,
WiMAX and WLAN applications[6] . The total radiation
efficiency is about 76% at 1.9GHz , 88% at 3.5GHz and 90 %
at 5.4GHz in all three bands shown in fig.4 .The axial ratio is
below 3db in all given frequency range from 1 GHz to 6 GHz
shown in fig.5, and VSWR in all the three frequency bands is
near about 1 as shown on fig.6. Impeadance matching in smith
chart is shown in fig.7. The antenna peak gain is 5.8dBi and at
1.9GHz and 3.5GHz gain is 3dBi and at 5.4GHz gain is 4.4
dBi .The gain versus frequency graph is given in figure 8. The
antenna directivity is 4.4 dBi at 1.9GHz , 3.8 dBi at 3.5GHz
and at 5.4GHz directivity is 5.8 dBi and the peak directivity is
7.3dBi . The directivity versus frequency graph is shown in
figure 9.
Fig.4 Antenna Efficiency of the proposed design
Fig.5. Axial Ratio of proposed array antenna
Fig.3 Return loss of the proposed array antenna
Fig.6 VSWR of proposed array antenna
39

ISSN 2249-6343
International Journal of Computer Technology and Electronics Engineering
(IJCTEE) Volume 3, Issue 2, April 2013
VI. CONCLUSION
Fig.7.Smith Chart of proposed array antenna
The antenna is designed successfully and simulated with
simple experimental approach to study the multiband
antenna array with mutual cupling . The antenna covers the
operating frequency band from 1.8GHz to 5.7GHz with
good return loss characteristics. The result shows in three of
the operating bands the antenna suffered in bandwidth
performance which can be further optimized to improve.
The antenna exhibited good impedance matching in all the
operating bands and attained a peak gain of 5.8 dBi .The
radiation characteristics resulted with a directivity of 7.4dBi
without sidelobes and possess broad beamwidth to provide
good coverage in desired directions for communication
applications. The attained bands of operation make the
antenna most suitable for applications such as GSM ,
WLAN, WIMAX communications .
References
[1] Balanis, C.A., Antenna Theory Analysis and Design, 3 rd
edition , John Willy & Sons, 2005
[2] R. J. Mailloux, Phased Array Antenna Handbook.
London: Artech House,2005.
[3] Shuguang CHEN and Ryuichi WATA “Mutual Coupling
Effects in Microstrip Patch Phased Array Antenna ” ”
IEEE Antenna & Prop. Symp., June 1998.
Fig.8. Gain of proposed array antenna
[4] Q. R. Zheng, Y.Q. Fu , N.C. Yuan, “ A novel compact
spiral electromagnetic band-gap(EBG) structure, ” IEEE
Trans. Antennas Propag. , Vol.56 ,no.6 ,pp.1656-1660 ,
June 2008.
[5] Y. Yusuf and X. Gong, “A low-cost patch antenna
phased array with analog beamsteering using mutual
coupling and reactive loading ,” Antenna and Wireless
Propag. Letters, IEEE, Vol.7, pp. 81-84 , 2008.
[6] M. A. Soliman , T. E. Taha, W. Swelam , and A. Gomaa
“3.5/5 GHz DUAL BAND 8×8 ADAPTIVE ARRAY
ANTENA,” Progress In Electromagnetics Research ,
Vol. 34, 85-98,2013.
Fig.9. Directivity of Proposed array antenna
40