1. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 –
6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 3, March (2014), pp. 13-17 © IAEME
13
COMPLEMENTARY SYMMETRY E-SLOT RECTANGULAR MICROSTRIP
ANTENNA FOR TRIPLE OPERATION
Dr. Nagraj K. Kulkarni
Government College, Gulbarga-585105, Karkataka, India
ABSTRACT
This paper focuses on the design and development of a complementary symmetry E – slot
rectangular microstrip antenna for triple band operation. The antenna has a structure of 8 X 5 X 0.16
cm3
and operates between the frequency range of 5.39 to 8.87 GHz giving a maximum impedance
bandwidth of 17.5% with a peak gain of 2.84 dB. The simple low cost glass epoxy substrate material
is used to fabricate the antenna. The microstripline feed arrangement is used to excite the antenna.
The experimental and simulated results agree each other. 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 operating in
IEEE 802.11a and C-band of frequencies.
Key words: Microstrip Antenna, Complementary Symmetry, E Slot, Triple Band.
1. INTRODUCTION
In today’s modern communication era, the microstrip antennas have attained good class of
devices that are needed for transmit/receive purpose in emerging communication applications such as
WLAN, WiMax and 3G-4G mobile systems, because of their numerous inherent advantages like low
profile, low fabrication cost, integrability with MMICs and ease of installation [1]. But an antenna
operating at single, dual and triple band is more attractive to use the device for the desired set of
frequencies. The wideband antennas are realized by many methods such as, slot on the patch, arrays,
monopoles [2-4]. etc. But in this communication a simple rectangular microstrip antenna with
complementary symmetry E-slots on the radiating patch is used to achieve triple band operation.
This kind of geometry is found to be rare in the literature.
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ISSN 0976 – 6464(Print)
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Volume 5, Issue 3, March (2014), pp. 13-17
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2. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 –
6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 3, March (2014), pp. 13-17 © IAEME
14
2. ANTENNA DESIGN
The conventional rectangular microstrip antenna (CRMSA) and the proposed complementary
symmetry E-slot rectangular microstrip antenna (CSERMSA) 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
feed the microwave power.
Figure 2: Top view geometry of CSERMSA.
Figure 2 shows the top view geometry of CSERMSA. The complementary symmetry E
shaped slot of width 2 mm having upper, side and middle arm lengths L1, L2 and L3 respectively is
placed at the middle of the patch. The bottom side is a tight copper shield ground plane. The
dimensions L1, L2 and L3 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 CSERMSA.

3. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 –
6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 3, March (2014), pp. 13-17 © IAEME
15
Table 1: Design parameters of CRMSA and CSERMSA
Antenna L W Lf Wf Lt Wt A B L1 L2 L3
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
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 CSERMSA. The Ansoft high frequency structure
simulation software is used to simulate the CRMSA and CSERMSA.
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 %. The simulated result is also shown in Fig.3
Figure 3: Variation of return loss versus frequency of CRMSA
Figure 4: Variation of return loss versus frequency of CSERMSA

4. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 –
6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 3, March (2014), pp. 13-17 © IAEME
16
Figure 4 shows the variation of return loss versus frequency of CSERMSA. It is clear from
this figure that, the antenna operates for three bands BW1 = 9.7 % (5.39-5.94 GHz), BW2 = 14.4 %
(6.13-7.08 GHz) and BW3 = 17.5 % (7.44-8.87 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. Furthermore, CSERMSA uses less
copper area of 50.02 % when compared to the copper area of CRMSA by placing slots on the
patch. The simulated result is also shown in Fig.4.
Figure 5: Radiation pattern of measured at 5.665 GHz
The far field co-polar and cross-polar radiation patterns of the proposed antenna is measured
in its operating band. The typical radiation pattern of measured at 5.665 GHz is shown in Fig. 5.
From this figure it is observed that, the pattern is 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 measured in BW1 is found to be
2.84 dB with a half power beam width of 590
.
4. CONCLUSION
From this study it is concluded that, CSERMSA gives triple bands with a maximum
bandwidth of about 17.5 % with a peak gain of 2.84 dB. The antenna exhibits broadside radiation
characteristics with linear polarization. The proposed antenna uses low cost substrate material with
simple design and fabrication. This antenna may find applications for systems operating in IEEE
802.11a and C-band of frequencies.
REFERENCES
1. Constantine A. Balanis, “Antenna theory: analysis and design”, John Wiley, New York,
(1997).
2. Girish Kumar and K. P. Ray, “Broadband microstrip Antennas”, Artech House, Boston,
London, 2003. Sang Ho Lim, Chae Hyun Jung, Se Young Kim and Noh Hoon Myung
“Analysis and Modeling of Dual band ACMPA with Asymmetric Crossed Slots”, Microwave
and Opt. Technol. Lett. Vol. 53, No.3, pp.681- 686, March 2011.

5. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976
6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 3, March (2014), pp.
3. Wen-Tsan Chung, Ching-Her
Antenna Design For WLAN / UWB Applications
51, No. 12, pp. 2874- 2878, Dec 2009.
4. Bahl, I. J. and P. Bhartia, “Mi
5. Nagraj Kulkarni and S. N. Mulgi
Rectangular Microstrip Antenna
and Communication Engineering &
ISSN Print: 0976- 6464, ISSN Online: 0976
6. M. Veereshappa and Dr.S.N Mulgi
Microstrip Antennas for Quad
Communication Engineering &
171, ISSN Print: 0976- 6464, ISSN Online: 0976
7. M. Veereshappa and S. N. Mulgi
for Triple-Band Operation and Virtual Size Reduction
and Communication Engineering &
pp. 176 - 182, ISSN Print: 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 Assi
Electronics Government
field of Microwave Electronics.
International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976
), Volume 5, Issue 3, March (2014), pp. 13-17 © IAEME
17
Her Lee and Chow -Yen- Desmond Sim. “Compact
For WLAN / UWB Applications”, Microwave and Opt.Technol. Lett. Vol.
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 1
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
Communication Engineering & Technology (IJECET), Volume 4, Issue 2, 201
6464, ISSN Online: 0976 –6472.
nd S. N. Mulgi, “Rectangular Slot Loaded Monopole Microstrip Antennas
nd Virtual Size Reduction”, International Journal of Electronics
and Communication Engineering & Technology (IJECET), Volume 4, Issue
int: 0976- 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 Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 –
© IAEME
Compact Monopole
Microwave and Opt.Technol. Lett. Vol.
Antennas”, Artech house, New Delhi, 1980.
Slot Triple Band Tunable
ournal of Electronics
1, 2012, pp. 1 - 9,
Corner Truncated Rectangular Slot Loaded Monopole
ournal of Electronics and
, 2013, pp. 165 -
Rectangular Slot Loaded Monopole Microstrip Antennas
ournal of Electronics
, Issue 1, 2013,
his M.Sc, M.Phil and Ph. D degree in Applied
Electronics from Gulbarga University Gulbarga in the year 1995, 1996 and 2014
stant professor and Head, in the Department of
Degree College Gulbarga. He is an active researcher in the