International Journal of Engineering Trends and Technology (IJETT) – Volume 22 Number 9-April 2015
Design of Vlinder shaped multiband patch antenna
for Super high frequency andUltra wide band
applications
D.Naresh kumar1, D.Santosh2, K.Santosh3, KVS Kousik4 , M.Poornima5
Associative professor in ECE department, Lendi Institute of Engg. & Tech., Andhra Pradesh, India1
Student of ECE department, Lendi Institute of Engg. & Tech., Andhra Pradesh, India 2,3,4,5.
Abstract— A Multi Frequency wide Band Vlinder (Butterfly)
shaped Rectangular Microstrip Patch Antenna is designed on
glass epoxy FR-4 substrate. The performance of this antenna is
compared with that of a modified rectangular patch antenna.
The simulated results for this antenna are optimized by varying
the shape of rectangular patch antenna. The results indicate that
the designed structure resonate at various closely spaced
frequencies which are use full for Ultra wide band (UWB)
communication systems, which has been allocated IEEE
802.15.3a standard for specifies the frequency range 7.96GHz to
10.32GHz and 10.32GHz to 12.93GHz. The Modified antenna
offers much improved wide bandwidth of 4.97GHZ at central
resonance frequency 10.44GHz in comparison to a rectangular
patch antenna. The directivity of antenna also improves
significantly at some of the resonance frequencies.
Keywords— Microstrip patch antenna , Rectangular patch,
bandwidth,resonant frequency, return loss, VSWR, Reflection
coefficient (key words).Introduction
I.
INTRODUCTION
Micro strip antennas consist of a very thin metallic strip
(patch) on a grounded substrate found extensive applications
in different fields due to their attractive features [3]. These
antennas are low profile, light weight, compact and
conformable structure and easy to fabricate [1] [4]. These
antennas have drawn attentions of scientific community over
the past decades. These antennas may easily be put easily on
any surface and may be easily coupled with MIC components.
However their low bandwidth and gain values restrict their
commercial applications [1] [4]. Now a day, the scientific
community is deeply involved in improving their performance
so that these may replace other antenna structures in modern
communication systems. Now, we are developing Vlinder
shaped multiband patch antenna for UWB applications. It
gives appropriate results with multiband operations with
accurate [3].
The important antenna characteristics are
Return loss,
Antenna
Radiation pattern,
VSWR.
The radiation pattern of an antenna is a plot of relative
field strength of the radio waves emitted by an antenna at
different angles. The radiation of many antennas shows the
pattern of maxima or lobes at various angles separated by
nulls angles where the radiation falls to zero. The lobe in that
ISSN: 2231-5381
direction is desired larger than the others and is called the
main lobe. The other lobes usually represent unwanted
radiation and are called side lobes [1] [2]. In communications,
return loss is the loss of signal power resulting from the
reflection caused at a discontinuity in a transmission line. This
discontinuity can be mismatch with the terminating load (or)
with a device inserted in the line. It is usually expressed at a
ratio in decibels (dB);
RL (dB) =10log10 (Pi /Pr). ----------- (1)
A match is good if the return loss is high and for a lower
insertion loss higher return loss is desirable. Taking the ratio
of reflected to incident power, we obtain a return loss is
negative.
RL’ (dB) =10log10 (Pr/Pi). ----------- (2)
The return loss with negative sign is called as reflection
coefficient. Caution is required when discussing increasing
(or) decreasing return loss. Since these terms strictly have the
opposite meaning when return loss is defined as a negative
quantity. The Standing Wave Ratio is usually defined as a
voltage ratio called the VSWR. The SWR in terms of current
is the ISWR. The power standing wave ratio is defined as the
square of the VSWR [7]. A problem with transmission lines is
that impedance mismatch in the cable tend to reflect the radio
wave back toward the source and of the cable preventing all
the power from reaching the destination end. An infinite SWR
represents the complete reflection, with all the power reflected
down the cable. The SWR of a transmission line can be
measured by an instrument SWR meter. SWR measures the
relative size of the reflection. An ideal transmission line
would have SWR of 1:1 and there is no reflection. The SWR
can be measured by SWR meter and SWR is a standard part
installing and maintaining on a transmission line [6].
Ultra-wideband is a radio technology that can be used at
very low energy levels for short-range high-bandwidth
communications. Ultra-Wideband (UWB) is a technology for
transmitting information spread over a large bandwidth (>500
MHz). Thus, pulse-based systems—where in each transmitted
pulse instantaneously occupies the UWB bandwidth or an
aggregation of at least 500MHz worth of narrow band carriers.
Each pulse in a pulse-based UWB system occupies the entire
UWB bandwidth, thus reaping the benefits of relative
immunity to multipath fading (but not to inter symbol
interference), unlike carrier-based systems that are subject to
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International Journal of Engineering Trends and Technology (IJETT) – Volume 22 Number 9-April 2015
both deep fades and inter symbol interference[1][8]. A
significant difference between traditional radio transmission
and UWB radio transmission is that the traditional systems
transmit information by varying the power level, frequency,
and/or phase of a sinusoidal wave [7]. UWB transmissions
transmit information by generating radio energy at specific
time instants and occupying large bandwidth thus enabling a
pulse-position or time-modulation. Another valuable aspect of
pulse-based UWB is that the pulses are very short in space
(less than 60 cm for a 500 MHz wide pulse, less than 23 cm
for a 1.3 GHz bandwidth pulse), so most signal reflections do
not overlap the original pulse, and thus the traditional
multipath fading of narrow band signals does not exist. A
February 14, 2002 Report and Order by the FCC authorizes
the unlicensed use of UWB in 3.1–10.6 GHz [10].
II. ANTENNA DESIGN AND CONFIGURATIONS
The antenna structure is having two circular slots in the
ground plane with a butterfly shaped antenna. This structure is
fed by a single micro strip line which ends in a truncated
patch. For good antenna performance a thick dielectric
substrate having low dielectric constant is desirable. This
provides better efficiency, larger bandwidth and better
radiation.
The slot antenna is fed by a truncated open ended micro
strip line 0.85mm thick FR4 substrate with a dielectric
constant of 4.2 is used in our design. The antenna is fed with
50 Micro strip line and is printed on the FR4 substrate with
the height (h) of 0.5 mm and relative permittivity r = 4.4
(dielectric constant) with loss tangent = 0.019.
III.
Denotation
A
B
C
D
E
F
G
H
I
J
ISSN: 2231-5381
Length(mm)
9.1
9.1
1.9
3.7
4.9
1.7
2.9
1.5
2
5
Table 2 :- Dimensions of ― V ― shape slotted microstrip patch antenna
Denotation
A
B
C
D
E
F
G
H
I
J
K
Outer regular Hexagon side
Inner regular Hexagon side
IV.
(a)
(b)
Fig 1:- Vlinder shaped microstrip antenna
(a)with circular slots
(b)with ― V ― shaped slots
DESIGN DIMENSION
Table 1: Dimensions of circular slotted microstrip patch antenna
Length(mm)
9.1
9.1
1.9
3.7
4.9
1.7
2.9
1.5
3.5
5
2.8
1
0.5
SIMULATED RESULTS
The microstrip patch antenna is simulated on HFSS
software that is a full-wave electromagnetic simulator based
on the method of moments. It analyzes 3D and multilayer
structures of general shapes. It has been widely used in the
design of MICs, RFICs, patch antennas, wire antennas, and
other RF/wireless antennas. It can be used to calculate and
plot the S11 parameters, VSWR, current distributions as well
as the radiation pattern. Computer simulations were done for
different loop perimeter and results were obtained for a center
frequency of 1.5 GHz as an observation as the loop perimeter
increase the resonance frequencies decreases The optimized
results for the return loss are compared for both of the
structures and all the results are almost invariant.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 22 Number 9-April 2015
Fig 4(a)
Fig 4(b)
Fig 4: surface current distribution of microstrip patch
antenna
(a) For circular slots
(b) For ―V― shaped slots
Fig 2(a):- Gain plots of circular slotted microstrip patch
antenna
Fig 5(a)
Fig 5(b)
Fig: 3D Radiation pattern of Vlinder shaped microstrip patch
antenna
Fig 5(a) With circular slots
Fig 5(b) With ― V ‖ slots
Radiation Pattern 1
Fig 2(b):- Return loss plot of circular slotted microstrip
patch antenna
Patch_Antenna_ADKv1
ANSOFT
Curve Info
0
-30
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='0deg'
30
0.96
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='5deg'
0.72
-60
60
0.48
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='10deg'
0.24
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='15deg'
-90
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='20deg'
90
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='25deg'
-120
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='30deg'
120
-150
150
-180
Fig 6(a):- Radiation pattern for circular slotted microstrip
patch antenna
Radiation Pattern 1
Fig 3(a):- Gain plots of ― V ― shape slotted microstrip
patch antenna
Name
X
dB(St(1,1))
0.00 7.4121
m1
Return Loss
Y
10.2261 -13.8044
m3
12.1357 -11.6206
Curve Info
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='0deg'
30
0.96
Patch_Antenna_ADKv1
-9.9110
m2
Patch_Antenna_ADKv1
0
-30
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='5deg'
ANSOFT
0.72
Curve Info
dB(St(1,1))
Setup1 : Sw eep1
-60
60
-2.00
0.48
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='10deg'
-4.00
0.24
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='15deg'
-90
-6.00
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='20deg'
90
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='25deg'
-8.00
m1
rETotal
Setup1 : LastAdaptive
Freq='10GHz' Phi='30deg'
-10.00
-120
m3
120
-12.00
m2
-14.00
5.00
7.50
10.00
Freq [GHz]
12.50
Fig 3(b) :- Return loss plot of ― V ― shape slotted microstrip
patch antenna
-150
15.00
150
-180
Fig 6(b):- Radiation pattern for ― V ― shaped slotted
microstrip patch antenna
V.
DISCUSION OF RESULTS
We need to find parameters of antenna such as return
loss, voltage standing wave ratio (VSWR), reflection
coefficient for calculating the efficiency of required patch
antenna.
For greater efficiency the value of VSWR of patch
antenna should be as low as possible
ISSN: 2231-5381
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Page 398
ANSO
International Journal of Engineering Trends and Technology (IJETT) – Volume 22 Number 9-April 2015
The parametric analysis of the patch antennas with circular
and ― V ― shaped slots are given below respectively.
[8] J. N. Lee and J. K. Park, ―compact uwb chip antenna design using the
coupling concept‖, pier 90, 341–351, 2009.
[9] Wayne S. T. Rowe, Rod B. Waterhouse, ―Investigation Into the
Performance of Proximity Coupled Stacked Patches‖, IEEE transactions of
antenna and propagation, vol. 54, no. 6, june 2006.
Table 3:- Parametric analysis of circular slotted microstrip patch antenna
Frequency(GHz)
7.96
10.32
12.93
Return
loss (dB)
19.62
17.81
21.01
VSWR
1.233:1
1.295:1
1.195:1
Reflection
coefficient
0.104
0.129
0.089
[10] Dan Sun and Lizhi You, ―A Broadband Impedance Matching Method for
Proximity-Coupled Microstrip Antenna‖, IEEE transactions and
propagations, vol. 58, no. 4, april 2010.
Table 4:- Parametric analysis of ― V ― slotted microstrip patch antenna
Frequency(GHz)
7.41
10.22
12.13
Return
loss (dB)
9.91
13.80
11.62
VI.
VSWR
1.939:1
1.513:1
1.712:1
Reflection
coefficient
0.319
0.204
0.262
CONCLUSION
Design and Analysis of Microstrip Patch antenna for
Super high frequency and Ultra Wide Band application is
presented in the paper. The obtained antenna parameters such
as Return Loss, VSWR and Reflection coefficient of the
designed antennas are obtained. Further, the size of the
antenna is obtained through parametric analysis. The designed
antenna met the requirements of SHF & UWB application.
From the above parametric analysis, by comparing
both the patch antennas, it is observed that the patch with
circular slots has better VSWR than that of the patch with ―V‖
slots. So the circular slotted patch is considered for better
efficiency in Super High Frequency & Ultra Wide Band
applications.
VII.
REFERENCES
[1] Constantine A. Balanis, Wiley, ―Antenna Theory Analysis and Design‖,
Restricted not for sale in North America Edition, 2005
[2] R. Garg, P. Bhartia, I. J. Bahl and A Ittipiboon, ―Microstrip antenna
design handbook‖, ArtechHouse:New York, 2001.
[3] Inc. NY, USA. Richard C. Johnson, Henry Jasik, ''Antenna Engineering
Handbook'', Second Edition 1984, pp 7 1 to 7 14, McGraw Hill, 2010
[4] K. L. Wong, ―Compact and Broadband Microstrip Antennas‖, John Wiley
& Sons. 2003
[5] J. Huang (1983), ―The finite ground plane effect on the Microstrip
Antenna radiation pattern‖, IEEE Trans. Antennas Propagate, vol. AP-31, no.
7, pp. 649-653
[6] Nader Engheta, Richard W. Ziolkowski, ―Metamaterial Physics &
Engineering Explorations‖, Wiley-IEEE Press, June 2006.
[7]T.Suganthi, Dr.S.Robinson, G.Kanimolhi,T.Nagamoorthy, ―Design and
Analysis of Rectangular Microstrip Patch Antenna for GSM Application‖,
IJISET - International Journal of Innovative Science, Engineering &
Technology, Vol. 1 Issue 2, April 2014.
ISSN: 2231-5381
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