2. P. Naveen Kumar, S. Chandramma, H. R. Ravi, Kishan Singh, Nagaraj Kulkarni, S. N. Mulgi
and P. V. Hungund
http://www.iaeme.com/IJECET/index.asp 2 editor@iaeme.com
Key words: Penta, T-Shape, Impedance Bandwidth and Microwave
Communication.
Cite this Article: Kumar, P. N., Chandramma, S., Ravi, H. R., Singh, K.,
Kulkarni, N., Mulgi, S. N. and Hungund, P. V. A Novel Design and
Evaluation of Rectangular Microstrip Antenna for Microwave Application.
International Journal of Electronics and Communication Engineering &
Technology, 6(7), 2015, pp. 01-07.
http://www.iaeme.com/IJECET/issues.asp?JTypeIJECET&VType=6&IType=7
_____________________________________________________________________
1. INTRODUCTION
The microstrip antennas (MSAs) is widely used in the communication system in a
broad range of application mainly because of their advantages, such as small size,
light weight, low profile, low volume , compatibility with integrated circuits ,low cost
etc. However, the main limitation of MSAs are their narrow impedance bandwidth
and lower gain. The antennas operating more than one band of frequencies is quite
useful than that of single band antennas. The multiband antennas are realized by many
methods such as, variable inductive or capacitive loads to the patch [1], loading of
shorting walls at different locations [2–3], impedance matching network [4], thick
substrates with low dielectrics constant [5], using multimode resonators [6−8], etc.
The MSAs with a slot cut inside the patch increases the gain and impedance
bandwidth without increasing the overall patch size. Hence in this study, a simple slot
loading technique has been used to construct the antenna which gives multiband
operation.
2. DESIGNING
The art work of proposed antennas is sketched using software Auto-CAD and
fabricated through photolithographic process on low cost glass epoxy substrate
materials of thickness h = 1.66 mm, relative permittivity εr = 4.2. Figure 1 shows the
geometry of CRMA designed on a substrate of area M × N using the basic equations
available in the literature [8]. The Patch element is designed for the resonant
frequency of 4 GHz. The CRMA consists of radiating patch of length L and width W.
The feed arrangement consists of quarter wave transformer of length Lt and width Wt
which is used for better impedance matching between the microstripline feed of
length Lf , width Wf and center point (Cp) along the width of the rectangle
microstripline patch. At the tip of microstripline feed a 50 Ω coaxial SMA connector
is used for feeding the microwave power
Figure 2 shows the geometry of four T-shaped slot loaded rectangular microstrip
antenna (FTSRMA). Here the four T-shape slots are placed along the width and
length of the patch. The dimension of slots are taken in terms of λ0, where λ0 is the
free space wavelengths in cm corresponding to the design frequency of 4 GHz.The
feed geometry of Figure 2. remains same as that of Figure 1.
Further, two T-shaped slots are removed from FTSRMA. This antenna is named
as two T-shaped slot loaded rectangular microstrip antenna (TTSRMA) which is
derived from FTSRMA as shown in Figure 3. The design parameters of CRMA,
FTSRMA and TTSRMA are given in Table 1.
3. A Novel Design and Evaluation of Rectangular Microstrip Antenna for Microwave
Application
http://www.iaeme.com/IJECET/index.asp 3 editor@iaeme.com
M
N
Figure 1 Geometry of CRMA.
Figure 2 Geometry of FTSRMA.
Figure 3 Geometry of TTSRMA.
4. P. Naveen Kumar, S. Chandramma, H. R. Ravi, Kishan Singh, Nagaraj Kulkarni, S. N. Mulgi
and P. V. Hungund
http://www.iaeme.com/IJECET/index.asp 4 editor@iaeme.com
Table 1 Designed parameters of CRMA, FTSRMA and TTSRMA.
Designed parameters of proposed antennas in cm
L 1.68
Lt 0.96
Lf 0.75
Lg 0.75
W 2.32
Wt 0.05
Wf 0.32
Ws 0.1
3. EXPERIMENTAL RESULTS
The impedance bandwidth over return loss less than −10 dB for the proposed antennas
is measured on vector network analyzer. The variation of return loss versus frequency
of CRMA is as shown in Figure 4. It is clear from this figure that, the antenna
resonates for the design frequency of 4 GHz. This validates the design concept of
CRMA. Further from Figure 4 it is seen that, the antenna resonates for single band of
frequency BW1. The magnitude of BW1 is found to be 3.50 %. This is calculated
using the equation,
( )2 1
Impedance bandwidth 100 %
c
f f
f
−
= ×
where f2 and f1 are the upper and lower cutoff frequencies respectively, when its
return loss reaches −10 dB and fc is the center frequency between f1 and f2.
Figure 4 Variation of return loss versus frequency of CRMA.
The variation of return loss versus frequency of FTSRMA is as shown in Figure 5.
From this figure it is seen that, the antenna resonates for petaband of frequencies
BW2, BW3, BW4, BW5, and BW6 . The magnitude of each operating band is found to
be 1.14 %, 7.29 %, 1.6 %, 3.71% and 3.33% respectively. The multiband operation is
due to the independent resonance of Patch and slots inserted in the conducting patch
-20
-15
-10
-5
0
BW1
5420
ReturnLoss(dB)
Frequency(GHz)
5. A Novel Design and Evaluation of Rectangular Microstrip Antenna for Microwave
Application
http://www.iaeme.com/IJECET/index.asp 5 editor@iaeme.com
of FTSRMA [9]. By the construction of novel geometry of FTSRMA, the antenna
starts resonating higher than the designed frequency of 4 GHz.
Figure 6 shows the variation of return loss verses frequency of TTSRMA. From
this figure it is seen that, the antenna resonates for hexa band of frequencies i.e. for
BW7, BW8, BW9, BW10, BW11and BW12. The magnitude of each operating band is
found to be 2.70 %, 5.82 %, 12.15 %, 3.45 %, 7.30 %, and 7.13% respectively. It is
clear from the figure that the operating bands BW7, BW9 and BW11 is enhanced.
Further the upper operating band BW12 as shown in Figure 6 is enhanced from 3.71%
to 7.13% which is 1.92 % times more than the FTSRMA.
-35
-30
-25
-20
-15
-10
-5
0
BW4 BW6
BW5
BW3
BW2
161412108642
ReturnLoss(dB)
Frequency (GHz)
Figure 5 Variation of return loss versus frequency of OSRMA.
The gain of the proposed antennas is measured by absolute gain method .The
power transmitted Pt by pyramidal horn antenna power received Pr by antenna under
test (AUT) is measured independently. With the help of these experimental data, the
gain (G) in dB of AUT is calculated by using the formula,
( ) ( ) 0r
tdB dB
dBt
λP
= 10 log - - 20log
P 4πR
G G
where Gt is the gain of the pyramidal horn antenna and R is the distance between the
transmitting antenna and AUT. Using above equation the peak gain of FTSRMA and
TTSRMA measured in their operating bands is found to be 1.75 and 3.24 dB
respectively. Hence by the construction of TTSRMA enhances the gain by 1.85 times
more than the peak gain of FTSRMA.
6. P. Naveen Kumar, S. Chandramma, H. R. Ravi, Kishan Singh, Nagaraj Kulkarni, S. N. Mulgi
and P. V. Hungund
http://www.iaeme.com/IJECET/index.asp 6 editor@iaeme.com
Figure 6 Variation of return loss versus frequency of AOCSRMA.
Figure 7 E and H plane radiation patterns of CRMA measured at 3.97 GHz.
Figure 8 E and H plane radiation patterns of FTSRMA. measured at 8.021 GHz.
Figure 9 E and H plane radiation patterns of TTSRMA measured at 8.02 GHz.
0-10-20-30-40-50
0
30
60
90
120
150
180
210
240
270
300
330
Eco of Antenna
Hco of Antenna
Ecross of Antenna
Hcross of Antenna
0-10-20-30-40-50
0
30
60
90
120
150
180
210
240
270
300
330
Eco of Antenna
Hco of Antenna
Ecross of Antenna
Hcross of Antenna
0-10-20-30-40-50
0
30
60
90
120
150
180
210
240
270
300
330
Eco of Antenna
Hco of Antenna
Ecross of Antenna
Hcross of Antenna
7. A Novel Design and Evaluation of Rectangular Microstrip Antenna for Microwave
Application
http://www.iaeme.com/IJECET/index.asp 7 editor@iaeme.com
The radiation patterns of antenna are measured in an anechoic chamber. The co
and cross-polar patterns in E-plane and H-plane of the antenna are presented in
Figures 7−9. From these figures it is clear that, the E and H plane patterns are broad
sided and are nearly same with each other.
4. CONCLUSION
From the detailed experimental study it is concluded that, by using four t-shaped slots
in CRMA i.e., FTSRMA makes the antenna to resonate for pentaband of frequencies
and gives a peak gain of 1.75 dB. Further by removing two T-shaped two slots i.e.,
TTSRMA. The antenna resonates for hexa bands and gives a maximum impedance
bandwidth of 12.15%. This antenna also enhances the gain to 3.24 dB when compared
to the gain of FTSRMA without changing much in the radiation characteristics. These
antennas may find application in microwave communication.
REFERENCES
[1] Vandenbosch, G. A. E. and van de Capelle, A. R. Study of the capacitively fed
microstrip antenna element. IEEE Transactions on Antennas and Propagation,
42(12), 1994, pp. 1648–1652.
[2] Kumar, G. and Ray, K. P. Broadband Microstrip Antennas. Norwood, Mass,
USA: Artech House, , 2003.
[3] Lai, H. W. and Luk, K. M. Wideband stacked patch antenna fed by meandering
probe. Electronics Letters, 41(6), 2005, pp. 297–298.
[4] Zehforoosh, Y., Ghobadi, C. and Nourinia, J. Antenna design for ultra wideband
application using a new multilayer structure. PIERS online, 2(6), 2006, pp. 544–
549.
[5] Jazi, M. N., Firouzeh, Z. H., Sadeghi, H. M. and Askari, G. Design and
implementation of aperture coupled microstrip IFF antenna. PIERS online, 4(1),
2008, pp. 1–5.
[6] Abdipour, M., Moradi, G. and Shirazi, R. S. A Design Procedure For Active
Rectangular Microstrip Patch Antenna. International Journal of Electronics and
Communication Engineering &Technology (IJECET), 3(1), 2012, pp. 123–129.
[7] Dr. Kulkarni, N. K. Complementary Symmetry E-Slot Rectangular Microstrip
Antenna for Triple Operation. International Journal of Electronics and
Communication Engineering &Technology (IJECET), 5(3), 2014, pp. 13–17.
[8] Bhal, I. J. and Bharatia, P. Microstrip antennas. New Delhi: Artech House, 1981.
[9] Sameena, N. M., Konda, R. B. and Mulgi, S. N. A Novel slot for enhancing the
impedance bandwidth and gain of rectangular microstrip antenna. PIERS online,
11, 2009, pp. 11–19.
![P. Naveen Kumar, S. Chandramma, H. R. Ravi, Kishan Singh, Nagaraj Kulkarni, S. N. Mulgi
and P. V. Hungund
http://www.iaeme.com/IJECET/index.asp 2 editor@iaeme.com
Key words: Penta, T-Shape, Impedance Bandwidth and Microwave
Communication.
Cite this Article: Kumar, P. N., Chandramma, S., Ravi, H. R., Singh, K.,
Kulkarni, N., Mulgi, S. N. and Hungund, P. V. A Novel Design and
Evaluation of Rectangular Microstrip Antenna for Microwave Application.
International Journal of Electronics and Communication Engineering &
Technology, 6(7), 2015, pp. 01-07.
http://www.iaeme.com/IJECET/issues.asp?JTypeIJECET&VType=6&IType=7
_____________________________________________________________________
1. INTRODUCTION
The microstrip antennas (MSAs) is widely used in the communication system in a
broad range of application mainly because of their advantages, such as small size,
light weight, low profile, low volume , compatibility with integrated circuits ,low cost
etc. However, the main limitation of MSAs are their narrow impedance bandwidth
and lower gain. The antennas operating more than one band of frequencies is quite
useful than that of single band antennas. The multiband antennas are realized by many
methods such as, variable inductive or capacitive loads to the patch [1], loading of
shorting walls at different locations [2–3], impedance matching network [4], thick
substrates with low dielectrics constant [5], using multimode resonators [6−8], etc.
The MSAs with a slot cut inside the patch increases the gain and impedance
bandwidth without increasing the overall patch size. Hence in this study, a simple slot
loading technique has been used to construct the antenna which gives multiband
operation.
2. DESIGNING
The art work of proposed antennas is sketched using software Auto-CAD and
fabricated through photolithographic process on low cost glass epoxy substrate
materials of thickness h = 1.66 mm, relative permittivity εr = 4.2. Figure 1 shows the
geometry of CRMA designed on a substrate of area M × N using the basic equations
available in the literature [8]. The Patch element is designed for the resonant
frequency of 4 GHz. The CRMA consists of radiating patch of length L and width W.
The feed arrangement consists of quarter wave transformer of length Lt and width Wt
which is used for better impedance matching between the microstripline feed of
length Lf , width Wf and center point (Cp) along the width of the rectangle
microstripline patch. At the tip of microstripline feed a 50 Ω coaxial SMA connector
is used for feeding the microwave power
Figure 2 shows the geometry of four T-shaped slot loaded rectangular microstrip
antenna (FTSRMA). Here the four T-shape slots are placed along the width and
length of the patch. The dimension of slots are taken in terms of λ0, where λ0 is the
free space wavelengths in cm corresponding to the design frequency of 4 GHz.The
feed geometry of Figure 2. remains same as that of Figure 1.
Further, two T-shaped slots are removed from FTSRMA. This antenna is named
as two T-shaped slot loaded rectangular microstrip antenna (TTSRMA) which is
derived from FTSRMA as shown in Figure 3. The design parameters of CRMA,
FTSRMA and TTSRMA are given in Table 1.](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)