IJRREST
INTERNATIONAL JOURNAL OF RESEARCH REVIEW IN
ENGINEERING SCIENCE & TECHNOLOGY
(ISSN 2278–6643)
VOLUME-4, ISSUE-1, APRIL-2015
(Proceedings of “6th National Conference on Make in India PMs Vision : Role of Engineering and Management
Innovations to Achieve this Vision” Organised by Apex Group of Institutions, Karnal, Haryana, India, April-2015)
NARROWBAND MICROSTRIP PATCH ANTENNA FOR
RADAR APPLICATION
1
Vishal, 2Ritika Saini, 3Vishant Narang
1,2,3
AIMT, Karnal, Haryana, India
Email: [email protected], [email protected], [email protected]
1
Abstract— This paper presents a novel narrowband microstrip patch antenna for radar application. The proposed
antenna consists of rectangular radiating patch which provides a narrowband behavior and relatively good impedance
matching working in the band of 3-12 GHz. A parametric study is performed on three different antenna structures. The
measured results give three narrow band stable signal transmission within the band of interest. Proposed Antenna is
designed using ANSYS HFSS antenna design tool.
Keywords: Microstrip-feed, slot antenna, ultra wideband (UWB) antenna.
1. INTRODUCTION
Ultra-wideband (UWB) radio is an emerging and promising technology with uniquely attractive features
inviting major advances in wireless communications, networking, radar, imaging and positioning systems [1]. In
the U.S., the Federal Communications Commission (FCC) allocated the frequency band 3.1-10.6 GHz for UWB
applications in 2002. In either conventional communication systems or UWB communication systems, an
antenna plays a very crucial role. Owing to its wide bandwidth, high data rate, and short-range characteristics,
ultra wideband (UWB) communication has been widely used in radar and miniature laptop applications [2].
Ultra Wideband Radio (UWB) is a potentially revolutionary approach to wireless communication in that it
transmits and receives pulse based waveforms compressed in time rather than sinusoidal waveforms compressed
in frequency [3].
In addition, for miniaturizing the wireless communication system, the antenna must also be small enough to be
placed inside the system. To achieve this, planar monopole antennas are good candidates for narrow-band
applications, as they exhibit narrow bandwidth, compact and simple structure, and ease of construction.
Moreover, the omnidirectional radiation properties of monopole antenna make them very suitable for basestation and for indoor applications [4].
Recently, there are various types of UWB antennas which have been designed to achieve the requirement for
different applications. The compact size microstrip antenna is presented that have its applications in UWB
frequency range is proposed [5]. Its bandwidth is impressive in view of its mechanical simplicity. However, it is
not the most suitable for portable communication systems due to the size of the antenna. A new modified low
profile small size UWB antenna is investigated.
In this paper, a Microstrip-fed Planar UWB antenna with Defected ground plane is used to improve the
bandwidth, radiation characteristics and overall performance of antenna [5].
2. ANTENNA GEOMETRY
2.1 Antenna 1
A design of compact size microstrip antenna is designed that have its applications in UWB frequency range is
shown in figure 1. The ground element of the proposed antenna is taken in the form of defected ground
structure. The antenna is fed by a microstrip feeding technique and printed on a dielectric Fr4 substrate of
dimension (30mm X 30 mm X 1.59mm) permittivity εr =4.4 and height h = 1.59 mm. The optimization on the
microstrip has been done to accomplish an -10 dB return loss criterion.
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IJRREST
INTERNATIONAL JOURNAL OF RESEARCH REVIEW IN
ENGINEERING SCIENCE & TECHNOLOGY
(ISSN 2278–6643)
VOLUME-4, ISSUE-1, APRIL-2015
(Proceedings of “6th National Conference on Make in India PMs Vision : Role of Engineering and Management
Innovations to Achieve this Vision” Organised by Apex Group of Institutions, Karnal, Haryana, India, April-2015)
Figure. 1: (a) Antenna Geometry (Top View)
Figure. 1:(b) Antenna Geometry (Bottom View)
Table 1 Antenna Description
S.NO
1
Description
Antenna Length
Value/mm
30
2
Antenna width
30
3
Substrate
thickness h
Feed Size
4
1.59
1.45
(a) Calculation of width of patch:
The width of the antenna is calculated by equation
(b) Calculation of effective dielectric constant:
The effective dielectric is calculated by equation
(c) Calculation of the effective length:
The effective length is calculated using equation
2.1.1 Results and Discussion
(a) S-Parameter
Figure 2 shows the simulated return losses (S parameter) of the proposed antenna. Basic description of antenna
is shown in Table 1. The antenna bandwidth that is lower than -10dB occupies 7.3 GHz. It can operate well in
UWB applications. The ground plane size selection is also based on the study on the microstrip slot antennas.
287 | P a g e | © IJRREST | h t t p : / / i j r r e s t . o r g / i s s u e s / ? p a g e _ i d = 1 2
IJRREST
INTERNATIONAL JOURNAL OF RESEARCH REVIEW IN
ENGINEERING SCIENCE & TECHNOLOGY
(ISSN 2278–6643)
VOLUME-4, ISSUE-1, APRIL-2015
(Proceedings of “6th National Conference on Make in India PMs Vision : Role of Engineering and Management
Innovations to Achieve this Vision” Organised by Apex Group of Institutions, Karnal, Haryana, India, April-2015)
Figure. 2: S-Parameter
(b) Smith Chart
The Smith Chart is a fantastic tool for visualizing the impedance of a transmission line and antenna system as a
function of frequency is shown in figure 3.
Figure.3: Port Impedance In terms of Smith Chart
(c) VSWR
Figure. 4:Frequency (GHz) versus VSWR plot
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IJRREST
INTERNATIONAL JOURNAL OF RESEARCH REVIEW IN
ENGINEERING SCIENCE & TECHNOLOGY
(ISSN 2278–6643)
VOLUME-4, ISSUE-1, APRIL-2015
(Proceedings of “6th National Conference on Make in India PMs Vision : Role of Engineering and Management
Innovations to Achieve this Vision” Organised by Apex Group of Institutions, Karnal, Haryana, India, April-2015)
VSWR graph is shown in figure 4 and it is defined in terms of the input reflection coefficient г as:
Γ is defined in terms of input impedance Zin of the antenna and the characteristic impedance Z0 of the feed line
as given below
2.2 Antenna 2
A compact size microstrip antenna is presented that have its applications in UWB frequency range. The antenna
is fed by a microstrip feeding technique and printed on a dielectric Fr4 substrate of permittivity εr =4.4 and
height h = 0.8 mm. The optimization on the microstrip has been done to accomplish an -10 dB return loss
criterion. Moreover, in comparison with a simple ground, the proposed design is modified which enhances the
bandwidth and improves input return loss.
UWB antenna consists of modified rectangular patch with two square slots which is embedded on to the lower
portion of patch (both right and left side).
Figure. 5: Antenna Geometry (Top View)
Figure. 6: Antenna Geometry (Bottom Veiw)
2.2.1Results and Discussion
(a) S-paramter
S-parameters describe the input-output relationship between ports (or terminals) in an electrical system. For
instance, if we have 2 ports (intelligently called Port 1 and Port 2), then S12 represents the power transferred
from Port 1 to Port 2. S21 represents the power transferred from Port 2 to Port 1. The S-parameter of above
designed is shown in figure 7.
The antenna is resonating at 8.3 GHz which covers only few bands of UWB. As return losses of antenna is 25dB.
289 | P a g e | © IJRREST | h t t p : / / i j r r e s t . o r g / i s s u e s / ? p a g e _ i d = 1 2
IJRREST
INTERNATIONAL JOURNAL OF RESEARCH REVIEW IN
ENGINEERING SCIENCE & TECHNOLOGY
(ISSN 2278–6643)
VOLUME-4, ISSUE-1, APRIL-2015
(Proceedings of “6th National Conference on Make in India PMs Vision : Role of Engineering and Management
Innovations to Achieve this Vision” Organised by Apex Group of Institutions, Karnal, Haryana, India, April-2015)
Figure. 7: S-parameter(antenna 2)
(b)VSWR
The most common case for measuring and examining VSWR is when installing and tuning transmitting
antennas. Ideally, VSWR must lie in the range of 1-2. Below figure 8 is shows the VSWR plot.
Figure. 8: VSWR Plot
(c) Smith Chart
Normalized scaling allows the Smith Chart to be used for problems involving any characteristic impedance or
system impedance, although by far the most commonly used is 50 ohms. Smith Charts can be used to increase
understanding of transmission lines and how they behave from an impedance viewpoint. Smith Charts are also
extremely helpful for impedance matching.
The Smith Chart is used to display a real antenna's impedance when measured on a Vector Network Analyzer
(VNA). Smith Charts is a useful tool for making the equations involved in transmission lines easier to
manipulate and is shown in Figure 9.
290 | P a g e | © IJRREST | h t t p : / / i j r r e s t . o r g / i s s u e s / ? p a g e _ i d = 1 2
IJRREST
INTERNATIONAL JOURNAL OF RESEARCH REVIEW IN
ENGINEERING SCIENCE & TECHNOLOGY
(ISSN 2278–6643)
VOLUME-4, ISSUE-1, APRIL-2015
(Proceedings of “6th National Conference on Make in India PMs Vision : Role of Engineering and Management
Innovations to Achieve this Vision” Organised by Apex Group of Institutions, Karnal, Haryana, India, April-2015)
Figure. 9: Smith Chart
2.3 Antenna 3
Further, to increase the overall performance of the former antenna, DGS technique is used .A compact size
microstrip antenna is presented that have its applications in UWB frequency range is shown in Figure 10-11.
The antenna is fed by a microstrip feeding technique and printed on a dielectric Fr4 substrate of permittivity εr
=4.4 and height h = 0.8 mm. The optimization on the microstrip has been done to accomplish an -10 dB return
loss criterion. Moreover, in comparison with a simple ground, the proposed design is modified which increases
the bandwidth and improves input return loss.
Figure. 10: Antenna Geometry (Top View)
Figure. 11: Antenna Geometry (Bottom Veiw)
2.3.1 Results and Discussion
(a) S-Parameter
S-parameters describe the input-output relationship between ports (or terminals) in an electrical system. For
instance, if we have 2 ports (intelligently called Port 1 and Port 2), then S12 represents the power transferred
from Port 1 to Port 2. S21 represents the power transferred from Port 2 to Port 1.In Figure 12, it is clearly shown
that the antenna exhibits higher frequency narrow band. By using DGS application, the antenna gives a
optimized result which fulfill all other requirement of UWB antenna.
291 | P a g e | © IJRREST | h t t p : / / i j r r e s t . o r g / i s s u e s / ? p a g e _ i d = 1 2
IJRREST
INTERNATIONAL JOURNAL OF RESEARCH REVIEW IN
ENGINEERING SCIENCE & TECHNOLOGY
(ISSN 2278–6643)
VOLUME-4, ISSUE-1, APRIL-2015
(Proceedings of “6th National Conference on Make in India PMs Vision : Role of Engineering and Management
Innovations to Achieve this Vision” Organised by Apex Group of Institutions, Karnal, Haryana, India, April-2015)
XY Plot 1
Ansoft Corporation
HFSSDesign1
0.00
-0.1882
Curve Info
dB(St(Cylinder2_T1,Cylinder2_T1))
Setup1 : Sw eep1
-5.00
dB(St(Cylinder2_T1,Cylinder2_T1))
-10.00
-15.00
-20.00
-25.00
-30.00
-35.00
-40.00
1.00
2.00
3.00
4.00
5.00
6.00
Freq [GHz]
7.00
8.00
9.00
10.00
11.00
MX1: 1.0000
Figure. 12: Return Loss
(b) VSWR
Figure. 13: VSWR Plot
Matching the impedance of the antenna to the impedance of the feed line is typically done using an antenna
tuner. The tuner can be installed between the transmitter and the feed line, or between the feed line and the
antenna. Both installation methods will allow the transmitter to operate at a low VSWR. Ideally, VSWR must lie
in the range of 1-2. Below figure 13 is shows the VSWR plot.
(c) Smith Chart
The Smith Chart is shown in figure 1.4 and plotted on the complex reflection coefficient plane in two
dimensions and is scaled in normalized impedance (the most common), normalized admittance or both, using
different colours to distinguish between them. These are often known as the Z, Y and YZ Smith Charts
respectively.
292 | P a g e | © IJRREST | h t t p : / / i j r r e s t . o r g / i s s u e s / ? p a g e _ i d = 1 2
IJRREST
INTERNATIONAL JOURNAL OF RESEARCH REVIEW IN
ENGINEERING SCIENCE & TECHNOLOGY
(ISSN 2278–6643)
VOLUME-4, ISSUE-1, APRIL-2015
(Proceedings of “6th National Conference on Make in India PMs Vision : Role of Engineering and Management
Innovations to Achieve this Vision” Organised by Apex Group of Institutions, Karnal, Haryana, India, April-2015)
Figure. 14: Smith Chart
3. CONCLUSION
In this paper, a microstrip-fed ultra-wideband planar monopole antenna is designed and studied. This antenna is
low profile small size antenna. Antenna 3 operates in the specified resonate at 3.4 GHz, 4.9 GHz and 8.3 GHz.
The simulation results and other measurement results of the designed antenna show a good agreement in terms
of the VSWR, antenna gain, and Smith chart.
4. REFERENCES
H. Wang and H. Zhang, “A CPW-Fed Ultra-Wideband Planar Inverted Cone Antenna,” Progress In Electromagnetics
Research C, Vol. 12, 101{112, 2010.
[2] Chow-Yen-Desmond Sim, Wen-Tsan Chung, and Ching-Her Lee, “Compact Slot Antenna for UWB Applications,”
IEEE Antennas and Wireless Propagation Letters, Vol. 9, 2010.
[3] Yashar Zehforoosh, Changiz Ghobadi, and Javad Nourinia, “Antenna Design for Ultra Wideband Application Using a
New Multilayer Structure,”PIERS Online, VOL. 2, NO. 6, 2006.
[4] R. Zaker, Ch. Ghobadi, and J. Nourinia, “A Modified Microstrip-Fed Two-Step Tapered monopole Antenna For UWB
and WLAN Applications,” Progress In Electromagnetics Research, PIER 77, 137–148, 2007.
[5] Loveleen Cheema1, Krishan Kumar Sherdia2, “ Design of Microstrip Antenna with Defected Ground structure for
UWB Applications,” International Journal of Advanced Research in Computer and Communication Engineering Vol.
2, Issue 7, July 2013.
[6] Ritika Saini, Davinder Parkash, “CPW fed Rectangular Shape Microstrip Patch Antenna with DGS for WLAN/WiMAX
Application,” International Journal of Advanced Research in Computer Science, Volume 4, No. 11, Nov-Dec 2013.
[7] Kirandeep Randhawa, Davinder Parkash, “Circular Shape Antenna Embedded with b-Shape Slot for UWB
Applications,” International Journal of Engineering Research, Volume No.3, Issue No.2, pp : 66-69 01 Feb. 2014.
[8] Vikas, Er.Baljinder Kaur, Krishan Sherdia, “Microstrip Patch Antenna for UWB Applications” International Journal
of Advanced Research in Computer and Communication Engineering Vol. 3, Issue 6, June 2014.
[9] Zuhura Juma Ali , “A Printed Microstrip Patch Antenna Design for Ultra Wideband Applications,” International
Journal of Science and Research (IJSR) Volume 3 Issue 4, April 2014.
[10] Kun Ma, Zhi Qin Zhao, Jiang Niu Wu, Mubarak S. Ellis, and Zai Ping Nie, “A Printed Vivaldi Antenna with Improved
Radiation Patterns by Using Two Pairs of Eye-Shaped Slots for UWB Applications,” Progress In Electromagnetics
Research, Vol. 148, 63{71, 2014.
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