International Journal of Science and Research (IJSR)

ISSN (Online): 2319-7064

Index Copernicus Value (2013): 6.14 | Impact Factor (2014): 5.611

Square Shaped Microstrip Patch Antenna at

2.45GHz
Sanjay R. Bhongale1, Pramod N. Vasambekar2
1
Department of Physics, Yashavantrao Chavan Institute of Science, Satara, PIN - 415 001, Maharashtra, India
2
Department of Electronics, Shivaji University, Kolhapur, PIN - 416 004, Maharashtra, India

Abstract: This paper communicates the design and study of parameters of square microstrip patch antenna. It is designed on FR4
substrate at resonance frequency of 2.45 GHz for ISM band using transmission line model. The thickness of substrate used is 1.542mm
with dielectric constant r = 4.4. The sides of patch are taken to be 29mm. The coaxial feeding is used for excitation of antenna. The
proposed antenna was designed and analyzed by using the ANSOFT Designer SV 2.2. Software. The Return loss, VSWR, Smith chart
and Radiation pattern for the designed antenna are simulated.

Keywords: Antenna theory, Microstrip antennas, coaxial feeding, Return loss, Radiation pattern.

1. Introduction
The rapid development of microstrip antenna technology
began in 1970. The basic microstrip antenna effects were
established in early 1980s. Now a days printed antennas
have been studied due to their wide applications over the
radiating antennas. These applications are light weight, low
cost, miniaturization, conformability and integration with
active device[1]. The microstrip patch antennas can be
designed and analyzed by number of software tools. The
microstrip fabrication technique is used to make patch Figure 1: Geometry of Rectangular microstrip patch
antennas. In present communication the square microstrip antenna.
patch antenna is designed and analyzed for parameters like
return loss, VSWR, smith chart, and radiation pattern by The models used for analysis MPAs are transmission line
using Ansoft Designer SV2.2[2]. model [8], cavity model [9] and full wave model or method
of moments [10]. The proposed antenna is analyzed by using
2. Theory of Patch Antenna transmission line model. The fringing field between patch
edge and ground plane makes the antenna to radiate. The
The MPA is a radiating patch on one side of dielectric effective dielectric constant reff ranges from 1 to r. The
substrate with ground plane on the other side. The patch is fringing fields present in dielectric substrate as well as spread
made up of conducting material such as copper or gold[3]. in air as depicted in Figure 2.
The shapes of microstrip patch antenna are circular [4],
rectangular [5], triangular [6] and square [7]. In present
communication square shape is used to design. The
dimensions of square patch length L, width W are taken to be
equal. The thickness of patch is t on dielectric substrate of
height h supported by ground plane. Such patch is depicted in Figure 2: Electric field lines
Figure 1 [8].
To feed the antenna variety of methods are used. They are
Theoretically the length L of radiating patch is kept in classified into two groups as contacting and non-contacting.
between 0.3330 and 0.050 (where o is the free space The contacting methods are stripline and coaxial probe, while
non-contacting are aperture coupling and proximity coupling
wavelength) the thickness of patch is kept as t << 0 while [1]. In present communication coaxial probe feeding method
height h of dielectric substrate is taken from 0.0030 to is used as depicted in Figure1 [8].
0.050 . The dielectric constant r of the substrate is kept in
The theoretical formulae for dimensions like width of patch
between 2.2 and 12. [3]. w [11], Effective dielectric constant reff [1], Extension
length L [12], Length of patch L [1] are given below.
W
c (1)
2 fr
r 1
2

Volume 4 Issue 10, October 2015

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Paper ID: SUB159062 1651
Licensed Under Creative Commons Attribution CC BY
 International Journal of Science and Research (IJSR)
ISSN (Online): 2319-7064
Index Copernicus Value (2013): 6.14 | Impact Factor (2014): 5.611
1
r 1 r 1 h 2 (2)
reff 1 12 W
2 2
0.264 reff 0.3
W

(3)
L 0.412
h
reff 0.258 W 0.8
h

2 L
c (4)
L
2 f r reff
where c Velocity of light in air,
Figure 3: Geometry of the designed coaxial feed (10, 12)
f r Resonance frequency,
microstrip patch antenna.
h Height of substrate.
The width of patch and length of patch of proposed square The frequency range for simulation is selected between 2.0
microstrip antenna is taken to be 29mm, dielectric material GHz to 2.8GHz. The variation of return loss with frequency
FR4 with r 4.4 , height of substrate h 1.542762mm . By is presented in Figure 4. The resonance frequency of square
using microstrip antenna calculator [13] the resonance microstrip patch antenna is observed to be 2.43GHz. for
frequency is analyzed to be f r 2.45 GHz . These stripline feeding and 2.4GHz for coaxial feeding. The return
loss at this resonance frequency is - 29.32 dB. With this
parameters are presented in Table I.
return loss the maximum power transmitted to the antenna is
99.87% [15]. The 3dB and 10 dB % bandwidths are 6.58 and
Table 1: Antenna Dimensions
2.05 respectively.
Parameter Dimensions
Dielectric Constant r 4.4
Height of substrate h 1.542 mm
Resonance frequency fr 2.45 GHz
Width of Substrate W 29.00 mm
Length of Substrate L 29.00 mm

3. Results and Discussion

Using Ansoft Designer SV2.2 software the proposed square
microstrip antenna is designed; particular location of feed
position for coaxial probe feeding is optimized and the
parameters like return loss, VSWR, smith chart and radiation Figure 4: Variation of return loss with frequency
pattern of antenna are simulated [2].
Figure 5 shows the variation of VSWR with frequency. The
3.1 Feed Point Location VSWR observed to be 1.29 at resonance frequency.
The coaxial probe feed point is located at point where input
impedance is 50 at analyzed resonance frequency. The
location of feed point coaxial feeding technique is optimized
in such way that the return loss is more negative at resonance
frequency at that point. Therefore, in coaxial probe feeding
the feed point is varied inside square patch. The position of
feed point was changed and the value of return loss for
number of times was observed by trial and error method [14].
The more negative return loss is found at a point (10, 12)
inside the square patch. Thus the coaxial feeding is fixed a
point (10, 12). The geometry of designed square microstrip
patch antenna of width and length of 29mm with proper feed
position (10, 12) coaxial feeding is presented in Figure 3 .
Figure 5: VSWR with frequency

The Smith chart of proposed square microstrip antenna is

represented in Figure 6. From radiation pattern of designed
square patch antenna presented in Figure 7, the half power
beam width is 62. All these parameters are listed in Table II.

Volume 4 Issue 10, October 2015

www.ijsr.net
Paper ID: SUB159062 1652
Licensed Under Creative Commons Attribution CC BY
 International Journal of Science and Research (IJSR)
ISSN (Online): 2319-7064
Index Copernicus Value (2013): 6.14 | Impact Factor (2014): 5.611
Line-Fed Patch Antennas, IEEE Transactions on
antenna and propagation, vol.49, No. 1, January 2001.
pp. 45-47.
[6] K Alameddine, S. Abou Chahine, M. Rammal, Z. Osman
Wideband patch antennas for mobile communication,
International. J. of Electron. Communication. (AEU) 60
(2006) pp.596-598.
[7] Deepak Sood, Gurpal Sing, Chander Charu Tripati,
Suresh Chander Sood & Pawan Joshi, Design,
fabrication and characterization of microstrip square
patch arrey for X-band applications, Indian Journal of
Figure 6: Smith chart Pure and Applied Physics, vol. 46, August 2008, pp.
593-597.
[8] K. O. Odeyemi, D.O. Akande, E.O. Ogunti Design of
an S-Band Rectangular Microstrip Patch Antenna,,
European Journal of Scientific Research, vol.55 No.1
(2011), pp.72-79.
[9] Seungbae Park, Cheolbok Kim, Youngho Jung Hosang
Lee, Dongki Cho, Munsoo Lee, Gain enhancement of a
microstrip using a Circularly periodic EBG structure and
air Layer, Int. J. Electron. Commun. (AEU) 64 (2010)
pp. 607- 613.
[10] Edward H. Newman, Pravit Tulit Analysis of
microstrip Antennas Using Moment Methods IEEE
Transaction on Antennas and propagation, Vol. AO-29,
No.1, January 1981.
Figure 7: Radiation pattern [11] James J. R. and Hall P.S. Handbook of Microstrip
Antennas, Peter Peregrinus, London, UK. (1989).
Table 2: Calculated Antenna Parameters [12] Ramesh G, Prakash B, Inder B, and Ittipiboon A
Serial Parameter Dimensions
Microstrip Antenna Design Handbook, Artech House.
No. 1 Resonance Frequency 2.43GHz
(2001).
2 Return loss 29.32dB
3 Power Transmitted 99.87% [13] http://www.emtalk.com/mpacalc.php.
4 3dB%Bandwidth 6.58 [14] V.V. Thakare & P. K. Singhal, Analysis of Feed point
5 10dB%Bandwidth 2.05 coordinates of a coaxial feed Rectangular Microstrip
6 VSWR 1.29 Antenna using Mlpffbp Artificial Neural Network ICIT
7 Half power beam width 62 2011 The 5th International Conference on Information
Technology.
4. Conclusion [15] www.markimicrowave.com.

The coaxial line fed square microstrip patch antenna at

2.45GHz is designed on Flame Retardant 4 substrate with
dielectric constant 4.4 for the application in ISM band. It is
studied by using ANSOFT-Designer SV2.2. It is observed
that resonance frequency is very close to analyzed resonance
frequency. The maximum power transferred to antenna is
99.87%.

References
[1] Pozer D.M. and Schaubert D.H, Microstrip Antennas,
the Analysis and Design of Microstrip Antennas and
Arrays, IEEE Press, New York, USA.(1995)A.
[2] Ansoft Designer, www.ansoft.com.
[3] Constantine A. Balanis, Antenna Theory, Analysis and
design, Third Edition John Wiley & Sons.
[4] Arun K. Bhattacharyya, Analysis of circular patch
antennas on electrically thick substrate, Computer
Physics Communication, vol. 68, 1991, pp.485-495.
[5] Loran I. Basilio, Michael A. Khayat, Jeffery, T.
Williams, Stuart A. Long The Dependence of the Input
Impedance on Feed Position of Probe and Microstrip

Volume 4 Issue 10, October 2015

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Paper ID: SUB159062 1653
Licensed Under Creative Commons Attribution CC BY