A Dual Band Microstrip Dipole Antenna For Wideband Application

ISSN 2249-6343
International Journal of Computer Technology and Electronics Engineering (IJCTEE)
Volume 2, Issue 6, December 2012
A Dual Band Microstrip Dipole Antenna
For Wideband Application
Nitali Garg, Zarreen Aijaz
Abstract - In this paper, the design of dual band microstrip
dipole antenna is incorporated with two different dipole arms. A
bandwidth of 22% and 40% around a center frequency of 2.4
GHz is obtained. It is a dual band microstrip dipole antenna
with minimum return loss of -36db. This antenna is designed on
a FR4 substrate with a dielectric constant 4.4 on double sided
PCB. This antenna is low cost, easy to design and light weighted;
easy to convince for mass production.
Index Terms— microstrip antenna, printed dipole, resonant
antenna, Frequency band.
I. INTRODUCTION
In modern wireless communication system; the design of
an antenna is required, that will operate in a wide band or
multiband mode, which also cover several different services.
A microstrip dipole is a good and easy approach, for a system
where an Omni directional pattern is required, as for example
in a portable device. Microstrip or printed dipole antenna
have been of the most popular type of antenna in the last
twenty years. In this paper, a tapered microstrip dipole
antenna is designed at the frequency of 2.4 GHz is proposed.
Then a wide band rectangular microstrip dipole antenna is
designed around the frequency of 2.4 GHz is adduced. Both
antennas are designed with additional arm and shorting plate.
The dimensions of additional arm and shorting plate are
designed in terms of guided wavelength. The bandwidth of
microstrip dipole antenna is very high as compared to the
microstrip patch antenna. Microstrip antennas are very
popular because of its low profile, low weight and low
production cost. If the antenna is to be implemented on the
same PCB as the circuitry, practically no additional costs
arise, that’s why microstrip antennas are very popular.
II. ANTENNA DESIGN AND ANALYSIS
In this paper, proposed half wave microstrip dipole antennas
are printed on a 1.6 mm thickness double sided FR4 substrate
with dielectric constant of 4.4 at operating frequency of
2.4GHz.
(Top view)
(bottom view)
Figure 1: Geometry of tapered microstrip dipole
antenna
The geometries of microstrip dipole antennas are shown in
figure 1 and figure 2. The effective wavelength of antenna is
calculated by using the formula
Where
And
Where
λg=Wavelength
F= Frequency
C= Velocity of light
=Effective dielectric constant of a microstrip line which is
=Dielectric constant
d = Substrate thickness
w= Width of microstrip line
All dimensions of proposed microstrip dipole antennas are
designed in terms of λg. The length, width and height of
substrate are taken respectively 3λg/4, λg/4 and λg/4/10.5.
Adduced antenna is excited by a 50 Ohm microstrip feed line.
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ISSN 2249-6343
International Journal of Computer Technology and Electronics Engineering (IJCTEE)
Volume 2, Issue 6, December 2012
(top view)
(bottom view)
Figure 2: Geometry of ractangular microstrip dipole
antenna
III. SIMULATION AND RESULT
Proposed microstrip dipole antenna has been simulated with
HFSS 13.0 from ANSYS software. The simulation results for
both dipole antennas are discussed in term of bandwidth
response and input return loss.
Figure 4: Return loss for microstrip dipole with tapered
arm.
(A) TAPERED MICROSTRIP DIPOLE WITH SHORTING PLATE
Figure 3 shows the side view of microstrip dipole antenna
with tapered arm. Proposed microstrip dipole antennas are
designed at a frequency of 2.4 GHz. In this figure, the ground
plane considered to be half of the substrate. The length and
width of ground plane is given by 1.5λg/4 and λg/4 respectively.
Figure 5: 3D polar plot of microstrip dipole
antenna
Figure 3: Microstrip dipole antenna with tapered arm
(side view).
Figure 4 represent the simulated return loss of microstrip
dipole antenna. The simulated bandwidth of microstrip dipole
antenna is 575.8 MHz and 60.6 MHz.
The maximum bandwidth of microstrip dipole with tapered
arm shorting plate is 22.12% is obtained.
Figure 5 and Figure 6 shows the 3D polar plot and radiation
pattern of microstrip dipole antenna respectively.
References of figure and results are taken from the HFSS 13.0
software.
Figure 6: 3D radiation pattern of microstrip dipole
antenna.
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ISSN 2249-6343
International Journal of Computer Technology and Electronics Engineering (IJCTEE)
Volume 2, Issue 6, December 2012
(B) RECTANGULAR DIPOLE WITH SHORTING PLANE
Instead of tapered arm; rectangular arm is used in
microstrip dipole antenna with shorting plate, which gives
wider bandwidth. The gap between dipole arms remains same
as well the ground Plane.
The side view of microstrip dipole with rectangular arm is
shown in Figure 7.
Figure 9: 3D polar plot for microstrip dipole antenna
with rectangular arm
Figure 7: Microstrip dipole antenna with rectangular
arm
The simulated return loss of microstrip dipole antenna is
presented in figure 8 with dual band.
In simulation result a dual band of 1.21 GHz and 60 MHz is
obtained. The 3D polar plot of proposed dual band microstrip
dipole antenna is also shown in figure 9.
ACKNOWLEDGMENT
Nitali garg thanks to Dr. Zarreen Aijaz who gave me the
possibility to complete this paper.
REFERENCES
[1] Floc'h, J.M.; Kokar, .Wide band printed dipole for Wi-Fi and WiMax
applications ”Antennas and Propagation Conference (LAPC), 2011
Loughborough , Page(s): 1 – 4.
[2] Jamaluddin, M.H.; Rahim, M.K. A.; Aziz, M. Z. A. Abd.; Asrokin, A.”
Microstrip dipole antenna for WLAN application” IEEE conference
publications, Publication Year: 2005, Page(s): 30 – 33.
[3] Qing-Qiang He; Bing-Zhong Wang; Jun He
“Wideband and Dual-Band Design of a Printed Dipole Antenna”
Antennas and Wireless Propagation Letters, IEEE Vol.7,2008 ,
Page(s): 1 – 4.
[4] Jwo-Shiun Sun; Guan-Yu Chen; Sen-Yi Huang; Chuang-Jen Huang;
Kuo-Liang Wu; Chen, Y.D.; Cheng-Hung Lin “The Omni-directional
Dipole Antenna Structure and Design” Antennas, Propagation & EM
Theory, 2006. Page(s): 1 – 4.
[5] Tsai,C.J.;Lin,C.S.;Chen,W.C.”A dual-band microstrip-matched print
ed antenna for WLAN/WiMax applications” Microwave Conference
Proceedings (APMC), 2011,Page(s): 1726 – 1729
[6] Floc'h, J.M.” Wide band printed dipole design” Mediterranean
Microwave Symposium (MMS), 2011, Page(s): 57 – 60.
[7] Ruina Wang; Quanyuan Feng “Design of a novel wideband microstrip
antenna” Electrical and Control Engineering (ICECE), 2011,Page(s):
2972 – 2974.
Figure 8: Return loss for microstrip dipole antenna with
rectangular arm.
IV. CONCLUSION
The performance of dual band microstrip dipole antenna
with two different arms on same ground plane has been
analyzed at a frequency of 2.4 GHz for wideband application
has been simulated in this paper. The shorting plate between
the ground plane and dipole arm improve the bandwidth of
antenna as well as provide double band. By using this shorting
plane technique 40% bandwidth with minimum return loss of
-36 db is obtained.
Nitali garg received her Bachelor of Engineering (Electronics
and communication) from Rajiv Gandhi Proudyogiki
Vishwavidyalaya, Bhopal in 2009 and currently she is pursuing
M-tech (digital communication) from the same institute. Her
research fields focus on microstrip antenna analysis and
designing
Dr. Zarreen Aijaz received her Bachelor of Engineering
(Electronics and telecommunication) from North
Maharashtra University Jalgaon (M.S.) India in 1997,
M.Tech (Microwave and millimeter waves) from Maulana
Azad National Institute of Technology, Bhopal, India and
doctorate (Design and development of double slot coupled
microstrip antenna) from Maulana Azad National Institute of Technology,
Bhopal, India. Her research fields focus on various antenna analysis, design
and measurement, high-frequency electromagnetic simulators. She has
authored several papers in national and international Journals and
conferences
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