1. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 –
6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 3, March (2014), pp. 37-41, © IAEME
37
COMPLEMENTARY SYMMETRY RECTANGULAR MICROSTRIP
ANTENNA FOR TRIPLE WIDEBAND OPERATION
Dr. Nagraj K. Kulkarni
Government College, Gulbarga-585105, Karkataka, India
ABSTRACT
In this work the design and development of a E–slot complementary symmetry rectangular
microstrip antenna is presented for triple wideband operation. The antenna has a volume of 80 X 50
X 1.6 mm3
and operates between the frequency range of 3.96 to 11.56 GHz giving a maximum
impedance bandwidth of 29.45% with a peak gain of 2.64 dB. The simple modified glass epoxy
substrate material is used to fabricate the antenna. The microstripline feed arrangement is employed
to excite the antenna. The antenna shows linearly polarized broadside radiation characteristic. The
design detail of the antenna is described. The experimental results are presented and discussed. This
antenna may find applications for systems in C and X-band of frequencies.
Key words: Microstrip antenna, complementary symmetry, E slot, triple band.
1. INTRODUCTION
In the recent years, the microstrip antennas have become good aids for transmit/receive
purpose in modern communication application like WLAN, WiMax and 4G mobile systems, because
of their numerous advantages like low profile, low fabrication cost, integrability with MMICs,
ruggedness and ease of installation [1]. But an antenna operating at single, dual and triple band is
more useful the device for the desired set of frequencies. The broadband antennas are realized by
many methods such as, slot on the patch, ground plane arrays, monopoles [2-4]. etc. But in this study
a simple rectangular microstrip antenna with complementary symmetry E-slots on the radiating patch
is used to get triple wideband operation with better gain. This kind of geometry is found to be rare in
the literature.
INTERNATIONAL JOURNAL OF ADVANCED RESEARCH IN ENGINEERING
AND TECHNOLOGY (IJARET)
ISSN 0976 - 6480 (Print)
ISSN 0976 - 6499 (Online)
Volume 5, Issue 3, March (2014), pp. 37-41
© IAEME: www.iaeme.com/ijaret.asp
Journal Impact Factor (2014): 7.8273 (Calculated by GISI)
www.jifactor.com
IJARET
© I A E M E

2. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 –
6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 3, March (2014), pp. 37-41, © IAEME
38
2. ANTENNA DESIGN
The conventional rectangular microstrip antenna (CRMSA) and the proposed E-slot
complementary symmetry rectangular microstrip antenna (ECSRMSA) are fabricated on low cost
glass epoxy substrate material of thickness h = 0.16 cm, loss tangent = 0.01 and εr = 4.2. The art
work of proposed antennas is sketched using the computer software AUTO CAD to achieve better
accuracy. The antennas are etched using the photolithography process.
Figure 1: Top view geometry of CRMSA
Figure 1 shows the top view geometry of CRMSA. The radiating patch of length L and width
W are designed for the resonant frequency of 3.5 GHz, using the basic equations available in the
literature [5]. A quarter wave transformer of length Lt and width Wt is used between CP along the
width of the patch and microstripline feed of length Lf and width Wf for matching their impedances.
A semi miniature-A (SMA) connector of 50 impedance is used at the tip of the microstripline to
supply the microwave power.
Figure 2: Top and bottom view geometry of ECSRMSA
Figure 2 shows the top and bottom view geometry of ECSRMSA. The complementary
symmetry E shaped slot of width 2 mm having upper, middle and lower arm lengths L1, L2 and L3 is
placed at the middle of the patch. The H shaped slot of width 2 mm having horizontal and vertical
arm lengths Hh and Hv is placed on the ground plane such that the middle point of this slot coincides
with the center of the radiating patch. The dimensions L1, L2, L3 Hh and Hv are taken in terms of λ0 ,
where λ0 is a free space wave length in cm corresponding to the designed frequency of 3.5 GHz.
Table 1 gives the design parameters of CRMSA and ECSRMSA.

3. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 –
6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 3, March (2014), pp. 37-41, © IAEME
39
Table 1: Design parameters of CRMSA and ECSRMSA.
Antenna L W Lf Wf Lt Wt A B L1 L2 L3 Hh Hv
CRMSA 2.04 2.66 2.18 0.32 1.09 0.06 5 8 - - - - -
CSERMSA 2.04 2.66 2.18 0.32 1.09 0.06 5 8 λ0 /14 λ0/ 6 λ0 /34 λ0/ 6 λ0 /7.5
3. RESULTS AND DISCUSSION
Vector Network Analyzer (The Agilent N5230A: A.06.04.32 ) is used to measure the
experimental return loss of CRMSA and ECSRMSA.
Figure 3 shows the variation of return loss versus frequency of CRMSA. From this figure it is
seen that, the CRMSA resonates at 3.39 GHz of frequency which is close to the designed frequency
of 3.5 GHz. The experimental bandwidth is calculated using the formula,
2 1
c
f f
Bandwidth (%) =
f
−
× 100
where, f2 and f1 are the upper and lower cut off frequencies of the resonated band when its
return loss reaches -10dB and fc is a centre frequency between f1 and f2. The bandwidth of CRMSA is
found to be 3.27 %.
Figure 3: Variation of return loss versus frequency of CRMSA
Figure 4: Variation of return loss versus frequency of ECSRMSA

4. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 –
6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 3, March (2014), pp. 37-41, © IAEME
40
Figure 4 shows the variation of return loss versus frequency of ECSRMSA. It is clear from
this figure that, the antenna operates for three bands BW1 = 29.49 % (3.96-5.33 GHz), BW2 = 28.78
% (6.87-9.18 GHz) and BW3 = 20.92 % (9.37-11.56 GHz) for the resonating modes of f1, f2 and f3
respectively. The BW1 is due to the fundamental resonance of the patch. The bands BW2 and BW3
are due to the complementary symmetry E slots on the patch. Further it can be noted that the
insertion of the H shaped slot on the ground plane, the bandwidth is enhanced in BW1 when
compared to the bandwidth of CRMSA. Furthermore, ECSRMSA uses less copper area of 50.02 %
when compared to the copper area of CRMSA by placing slots on the patch and ground plane.
Fig 5: Radiation pattern of CRMSA measured at 3.39 GHz
Fig 6: Radiation pattern of measured at 4.645 GHz
Figure 5 and 6 show the far field co-polar and cross-polar radiation patterns of CRMSA and
ECSRMSA measured in their operating bands. From these figure it is observed that, the patterns are
broadsided and linearly polarized. The gain of the proposed antenna is calculated using absolute gain
method given by the relation,
( ) 0r
t
λPG (dB) = 10 log - (Gt) dB - 20 log dB
P 4πR
 
 
 
where, Pt and Pr are transmitted and received powers respectively. R is the distance
between transmitting antenna and antenna under test i.e. The peak gain of ECSRMSA measured in
BW1 is found to be 2.64 dB with a half power beam width of 510
this shows directional property of
the antenna.
4. CONCLUSION
From this study it is concluded that, ECSRMSA gives triple wide bands with a maximum
bandwidth of about 29.45 % in BW1, a bandwidth of 28.78 % is obtained in BW2 and 20.92 % is
observed in BW3. The enhancement of bandwidth is caused due to the incorporation of H shaped slot
on the ground plane. The antenna exhibits broadside radiation characteristics with a peak gain of
2.64 dB. The proposed antenna uses low cost substrate material with simple design and fabrication.
This antenna may find applications for systems in C and X-band of frequencies.

5. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976
6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue
REFERENCES
1. Constantine A. Balanis, “Antenna theo
(1997).
2. Girish Kumar and K. P. Ray, “Broadband microstri Antennas”, Artech House, Boston,
London, 2003.
3. Sang Ho Lim, Chae Hyun Jung, Se Young
Modeling of Dual band ACMPA with A
Technol. Lett. Vol. 53, No.3,
4. Wen-Tsan Chung, Ching-Her
Antenna Design for WLAN / UWB Applications
Vol. 51, No. 12, pp. 2874- 2878,
5. Bahl, I. J. and P. Bhartia, “Microstrip
6. Nagraj Kulkarni and S. N. Mulgi, “Corner Truncated Inverted U
Rectangular Microstrip Antenna
and Communication Engineering &
9, ISSN Print: 0976- 6464, ISSN Online: 0976
7. M. Veereshappa and S. N. Mulgi
for Triple-Band Operation a
and Communication Engineering &
pp. 176 - 182, ISSN Print: 0976
8. M. Veereshappa and Dr.S.N Mulgi, “Corner Truncated Rectangular Slot Loaded Monopole
Microstrip Antennas for Quad
Communication Engineering &
171, ISSN Print: 0976- 6464, ISSN Online: 0976
BIO-DATA
Dr. Nagraj K. Kulkarni
Electronics from Gulbarga University Gulbarga in the year 1995, 1996 and 2014
respectively. He is working as an Assistant professor and Head, in the Department of
Electronics Government
field of Microwave Electronics.
International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976
6499(Online) Volume 5, Issue 3, March (2014), pp. 37-41, © IAEME
41
“Antenna theory: analysis and design”, John Wiley,
Girish Kumar and K. P. Ray, “Broadband microstri Antennas”, Artech House, Boston,
Sang Ho Lim, Chae Hyun Jung, Se Young Kim and Noh Hoon Myung
ACMPA with Asymmetric Crossed Slots”, Microwave and
No.3, pp.681- 686, March 2011.
Her Lee and Chow -Yen- Desmond Sim, “Compact Monopole
WLAN / UWB Applications”, Microwave and Opt.Technol. Lett.
2878, Dec 2009.
“Microstrip Antennas”, Artech house, New Delhi, 1980.
Nagraj Kulkarni and S. N. Mulgi, “Corner Truncated Inverted U - Slot Triple Band Tunable
Rectangular Microstrip Antenna for Wlan Applications” International Journal of Electronics
and Communication Engineering & Technology (IJECET), Volume 3, Issue
6464, ISSN Online: 0976 –6472.
nd S. N. Mulgi, “Rectangular Slot Loaded Monopole Microstrip Antennas
and Virtual Size Reduction”, International Journal of Electronics
and Communication Engineering & Technology (IJECET), Volume 4, Issue
, ISSN Print: 0976- 6464, ISSN Online: 0976 –6472.
nd Dr.S.N Mulgi, “Corner Truncated Rectangular Slot Loaded Monopole
or Quad-Band Operation”, International Journal of Electronics and
ng & Technology (IJECET), Volume 4, Issue 2
6464, ISSN Online: 0976 –6472.
Dr. Nagraj K. Kulkarni received his M.Sc, M.Phil and Ph. D degree in Applied
Electronics from Gulbarga University Gulbarga in the year 1995, 1996 and 2014
respectively. He is working as an Assistant professor and Head, in the Department of
Electronics Government Degree College Gulbarga. He is an active researcher in the
field of Microwave Electronics.
International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 –
, © IAEME
Wiley, New York,
Girish Kumar and K. P. Ray, “Broadband microstri Antennas”, Artech House, Boston,
Kim and Noh Hoon Myung, “Analysis and
symmetric Crossed Slots”, Microwave and Opt.
ompact Monopole
d Opt.Technol. Lett.
Antennas”, Artech house, New Delhi, 1980.
Slot Triple Band Tunable
ournal of Electronics
Technology (IJECET), Volume 3, Issue 1, 2012, pp. 1 -
Rectangular Slot Loaded Monopole Microstrip Antennas
ournal of Electronics
, Issue 1, 2013,
nd Dr.S.N Mulgi, “Corner Truncated Rectangular Slot Loaded Monopole
ournal of Electronics and
2, 2013, pp. 165 -
his M.Sc, M.Phil and Ph. D degree in Applied
Electronics from Gulbarga University Gulbarga in the year 1995, 1996 and 2014
respectively. He is working as an Assistant professor and Head, in the Department of
e Gulbarga. He is an active researcher in the