International Journal of Engineering Trends and Technology (IJETT) – Volume 48 Number 5 June 2017

Design and Performance analysis of

Microstrip Patch antenna for C band
applications
Divesh Mittal#1, Aman Nag*2, Ekambir Sidhu#3
1
IEEE student member, Department of Civil Engineering, Punjabi University, Patiala
2
IEEE student member, Department of Mechanical Engineering, Punjabi University, Patiala
3
IEEE member, Department of Electronics and Communication Engineering, Punjabi University, Patiala

Abstract - A microstrip feed compact rectangular face of a dielectric substrate with an incessant
microstrip antenna designed in CST 2016 has been conducting layer adhered to the opposite side of the
proposed and presented in this paper. The proposed substrate which forms a ground plane. The patch and
microstrip patch antenna design has been devised ground are usually made of material such as copper
using woven fiberglass cloth substrate (FR4) having or gold and different type of shapes can etched [1].
depth of 0.157 cm with a dielectric constant of (Ɛr= A patch antenna is an antenna having narrow
4.4) and loss angle of 3.18 degree. The ground, bandwidth and wide-beam of radiation fabricated by
patch and feedline are of copper material having photo etching technique on the dielectric substrate
conductivity and resistivity of 5.67 × 108 S/m and [2]. The microstrip patch antenna emanate because
1.69 × 10-7 Ω-m, respectively. A rectangular slot has of the collection of opposite charges forming
been cut in the upper rim of the patch to stint the fringing fields between the patch edge and the
resonant frequency. A small rectangular slot has ground plane. For optimum antenna performance
been added within the patch to increase the efficiency, a thick layer of dielectric substrate which
bandwidth performance of the antenna. The antenna must have low dielectric constant is considered
patch size after slotting has been abridged by necessary since this offers better proficiency, better
10.12% when compared to a conventional radiation and larger bandwidth [3]. But this
rectangular shaped microstrip patch antenna with a methodology leads to bulky profile antennas. The
maximum bandwidth of 2.65 GHz and return loss of researchers are working on different alternate
-60.29 dB. A broad scrutiny of the return loss methods to formulate the size of compact antenna.
pattern (dB), directive gain (dB), performance This can be attained by reducing the thickness of
efficiency and directivity (dBi) of the insinuated substrate and increasing the dielectric constant of the
antenna design has been tendered in this paper. The substrate which in turn decrease the performance
simple structure and low profile characteristics of proficiency of the microstrip patch antenna as well
the proposed antenna design make it easy to as narrow bandwidth [4]. The elements of facets of a
fabricate and employable in the field of wireless microstrip antenna hinge on the resonant frequency
communication system. The proposed antenna is and value of the dielectric constant [5]. Since
capable of operating in the C band having frequency microstrip antenna has limitation of narrow
range of 4 GHz – 8 GHz. The input impedance of bandwidth, many methods have been recommended
antenna is 49.96 ohms which meticulously matches for attaining the large bandwidth. These methods
with the input impedance of SMA cable having contain: using parasitic elements either in same layer
impedance of 50 ohms. This leads reduction in or in stacked layer, reduced ground and skimmed
reflection coefficient. The proffered antenna has the patch [6][7]. The dielectric substrate plays a
capability of being suitably deployed for ISM band, substantial role in the design and structural
maritime military systems, maritime communications, behaviour of microstrip antennas. In the proposed
SAR communications, aeronautical military systems, paper, the woven fiberglass cloth substrate (FR4)
land military systems and aeronautical has been chosen as substrate whose dielectric
communications. constant is 4.4. FR-4 glass epoxy is a prevalent and
multipurpose thermoset plastic with good
Keywords — Directivity, FR4, Gain, Microstrip mechanical toughness to weight ratio. The FR-4 is
Antenna Radiation pattern, VSWR. most generally used as an electrical insulator having
significant mechanical and thermal strength. It has
I. INTRODUCTION an extensive variability of applications [8]. A patch
The microstrip antenna elements emanate EM antenna supplies a maximum directive gain of 6-
waves proficiently as devices on the microstrip 9dBi. The impedance of a resonant micro strip
(PCB) printed circuit boards. The microstrip antenna antenna is from 150 to 400ohms and the coveted
comprises of an emanating conducting patch on one impedance is 50ohms [9]. The investigation of

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 International Journal of Engineering Trends and Technology (IJETT) – Volume 48 Number 5 June 2017

microstrip antennas has made significant The actual length, L of the patch is using the
development nowadays. The microstrip antennas following formula:
have more benefits. They are lighter in volume and
weight having low fabrication cost and conformity.
The microstrip antennas also offers dual bandwidths,
circular polarizations, multi frequency operations,
E. Length extension:
frequency agility, feed line flexibility, beam
scanning omnidirectional patterning. In this paper To determine the length extension, we use this
the microstrip patch antenna, types of microstrip formula:
patch antenna, different types of feeding
methodologies and their applications has been
discussed and compared with other conventional
antennas [10]. The most significant application of
microstrip antenna is in GPS systems. It is also used
in mobile communications; RFID; TAGS and Wi-Fi
applications [11].

II. DESIGN O VERVIEW

where c is the velocity of light.
To design a microstrip patch antenna, we have to
choose the resonant frequency and a dielectric The fig. 1 (a), fig. 1 (b) and fig. 1 (c) illustrates the
medium for which antenna is to be designed [12]. geometry of the propounded antenna. The fig. 1 (a)
The parameters to be calculated are as under [13]. represents the side view of the designed antenna.
The fig. 1 (b) represents the top view of the designed
A. Width of patch: antenna. In the propounded antenna design, the FR-4
(Flame Retardant) substrate of dielectric constant
The width of the patch is calculated using the value of Ɛr= 4.4 and thickness 0.157 cm has been
formula: used. The arrangement of substrate, patch, feed line
and ground are shown in fig. 1 (a). The copper
material is used for ground and patch. The
propounded microstrip antenna design has a
compact area of 32.01 × 21.86 mm2. The rectangular
patch of thickness 0.02 mm has been deposited on
B. Thickness of patch: the substrate. The input to the antenna is provided
The thickness of the patch is calculated using the through SMA connector via feedline of dimensions
formula: 2.72 x 5.60 mm2. The microstrip feedline provides
proper impedance matching of the antenna with
SMA connector which ensures that the maximum
power is delivered to antenna for radiation with
minimal reflection losses from antenna towards the
C. Effective dielectric constant: SMA connector. The antenna has input impedance
of 49.96 Ω which closely matches with the 50 Ω
The effective dielectric constant is given by the
impedance of SMA connector. The thickness of the
formula: substrates, feed line, patch and ground are given in
Table I. The antenna has been designed and
simulated by using CST Microwave Studio 2016.

Fig. 1 (a) Lateral view of the propounded antenna

design.
D. Length of patch:

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 International Journal of Engineering Trends and Technology (IJETT) – Volume 48 Number 5 June 2017

Ω which closely matches with desired port

impedance of 50 Ω.

Fig. 1 (b) Top view of the propounded antenna

design

Fig. 2(a) Return loss (S11) showing resonant

frequency of antenna design.

Fig. 1 (c) Spinal view of the propounded antenna

design.

III. TABLE I

ANTENNA DIMENSIONS
Antenna Dimensions Value (mm)
Fig. 2(b) Return loss plot (S11) showing bandwidth
Thickness of patch 0.02 of antenna design.
Thickness of substrate 1.57
Thickness of ground 0.02

IV. SIMULATED RESULTS

The recital of the antenna design has been perceived
in terms of return loss (dB), gain (dB), directivity
(dBi), resonant frequency (GHz), bandwidth (GHz),
VSWR and input impedance (ohms). The return loss
plot of the propounded antenna is shown in fig. 2. It
has been scrutinized that the propounded antenna
has resonant frequency of 5.54 GHz with the
corresponding return loss of -60.29 dB. The
bandwidth of propounded antenna is 2.65 GHz in the Fig. 3 Gain of antenna @ 5.54 GHz in CST 2016.
frequency range of 4.74 GHz – 7.40 GHz. It has
been examined that antenna has gain and directivity
of 3.3 dB and 3.08 dBi correspondent to the resonant
frequency of 5.54 GHz as shown in fig. 3 and fig. 4,
respectively. It has been observed that antenna has
E-field and H- field intensity of 18.04 dBV/m and -
33.48 dBA/m respectively at resonant frequency of
5.54 GHz as shown in fig. 5 and fig. 6. It has been
also analysed that the VSWR of the propounded
microstrip antenna design lies below the maximum
tolerable value of 2 within the operating frequency
range of antenna as shown in fig. 7. The fig. 8
illustrates the Smith chart plot of the propounded
antenna. It has been examined from the smith chart Fig. 4 Directivity of antenna @ 5.54 GHz in CST
that the propounded antenna has impedance of 49.96 2016.

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 International Journal of Engineering Trends and Technology (IJETT) – Volume 48 Number 5 June 2017

V. CONCLUSION
In this paper a rectangular microstrip antenna for
C band applications has been proposed and designed
using CST Microwave Studio 2016 software. It has
been examined that the antenna is resonant at a
frequency of 5.54 GHz with a return loss of -60.29
dB. The impedance bandwidth of antenna is 2.65
GHz ranging from 4.74 GHz to 7.40 GHz. The gain
and directivity obtained at resonant frequency is 3.3
dB and 3.08 dBi respectively. The antenna has
impedance of 49.96ohms, which makes it is easy to
connect a 50ohms transmission line to antenna to
Fig. 5 E-field plot of antenna @ 5.54 GHz in CST reduce impedance mismatching losses. The VSWR
Microwave Studio value at resonant frequency is less than the
maximum tolerable value (i.e. 2). The antenna
design can effectively be employed for C band
applications like aeronautical communications,
aeronautical military systems and land military
systems (5.45 GHz - 5.48 GHz), SAR
communication (5.48 GHz - 5.68 GHz), inductive
applications (5.73 GHz - 5.9 GHz), broadcasting
(5.9 GHz - 5.95 GHz), maritime communications,
maritime military systems (6.2 GHz - 6.5 GHz) and
ISM band (5.13 GHz) [14].

ACKNOWLEDGMENT

We are thankful to our honourable guide, Prof.

Fig. 6 H-field of antenna @ 5.54 GHz in CST 2016. Ekambir Sidhu currently designated as Assistant
Professor in Department of Electronics and
Communication Engineering at Punjabi University,
Patiala for his supervision of this work.

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 International Journal of Engineering Trends and Technology (IJETT) – Volume 48 Number 5 June 2017

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