-
International Journal of Electrical Electronics & Computer
Science Engineering
Volume 1, Issue 5 (October 2014), ISSN : 2348 2273
Available Online at www.ijeecse.com
1
Design, Fabrication and Performance Analysis of Microstrip
Antenna with MIMO
Implementation for Wireless Applications
Mohammad Ameen1, Mohammed Ismail. H
2
1P.G Scholar, Department of ECE, KMEA Engineering College,
Ernakulam, Kerala, India. 2Assistant Professor, Department of ECE,
KMEA Engineering College, Ernakulam, Kerala, India.
1 [email protected] , [email protected]
Abstract: This paper presents the design of a small and
compact
size triple band Microstrip line feed slot antenna and their
2x1
MIMO implementation for Bluetooth, 4G LTE, WLAN, and
WiMAX applications. The proposed slot antenna consist of a
microstrip feed line on one side of the substrate, a ground
plane
on another other side on which some slots are etched and
some
L strips are added. Two S shaped parasitic elements are
added
back to back on front side of the substrate. The simulation
results of the single antenna shows that the designed antenna
is
capable of operating over 2.39 to 2.86 GHz, 3.13 to 3.68
GHz,
and 5.08 to 5.97 GHz frequency bands while rejecting
frequency
ranges between these three bands. Next, a study was
performed
to implement this antenna in 2x1 MIMO arrangement on the
same circuit space. The simulation results of the MIMO
antenna shows that it is suitable for working in Bluetooth,
4G
LTE, WLAN and WiMAX applications. Nearly Omnidirectional
radiation pattern, acceptable antenna gain, better mutual
coupling and better envelope correlation coefficient are
achieved over the three operating bands. The proposed
antenna
is suitable for wireless communication systems.
Keywords: Multiple Input Multiple Output (MIMO); Wireless
Local Area Networks; Long Term Evolution; Worldwide
Interoperability for Microwave Access.
I. INTRODUCTION
Presently the wireless communication is one of the fastest
growing segment of the communication field. There are
many commercial and government applications such as
Satellite communication, mobile radio, and Wireless
communication where size, weight, cost, ease of
installation, performance, aerodynamics profile are major
constraints. The vision of the wireless communication
supporting information exchange between people and
devices is the communication frontier of the next few
decades. This vision will allow multimedia communication
from anywhere in the world. In the last few years, the
development of wireless local area networks (WLAN) and
WiMAX (Worldwide Interoperability for Microwave
Access), Bluetooth, 4G LTE (Long Term Evolution)
represented one of the principal interest in the information
and communication field. Also, in today’s environment,
technology demands antennas which can operate on
different wireless bands and should have different features
like low cost, minimal weight, low profile and are capable
of maintaining high performance over a large spectrum of
frequencies.
In this era of next generation networks require high data rate
and size of devices are getting smaller day by day. In
this evolution three important standards are 4G LTE, WiFi
(WLAN) and WiMAX. Wireless local area network
(WLAN) and WiMAX technology is most rapidly growing
area in the modern wireless communication. This gives
users the mobility to move around within a broad coverage
area and still be connected to the network [1-3]. This
provides greatly increased freedom and flexibility. For the
home user, wireless has become popular due to ease of
installation, and location freedom. For success of all these
wireless applications we need efficient and small antenna
as the size of the device is becoming smaller and smaller.
This being the case, portable antenna technology has grown
along with mobile and cellular technologies. It is important
to have the best performance antenna for a device. The best
performance antenna will improve transmission and
reception, reduce power consumption, last longer and
improve marketability of the communication device [4-5].
II. ANTENNA DESIGN
Fig. 1. Dimensions of front side and ground plane (unit:
mm).
The proposed antenna may be considered as a transformer
of the slot antenna. As shown in Fig. 1, the configuration of
the triple-band slot antenna is designed and substrate with
FR4, relative permittivity of 4.4, and a loss tangent of
0.02.
The entire size of the antenna is only 30X30x3.2 mm3.
Without loss of generality, a 50Ώ microstrip feed line with
a width of 3 mm is given for centrally feeding the antenna
at one side of the substrate and two S shaped parasitic
mailto:[email protected]:[email protected]
-
International Journal of Electrical Electronics & Computer
Science Engineering
Volume 1, Issue 5 (October 2014), ISSN : 2348 2273
Available Online at www.ijeecse.com
2
elements are added on one side of the substrate and Some
simple slots are etched on the ground plane to give all the
work bands.
Fig. 2.Configuration of the simulated antenna. (a) Case I. (b)
Case II. (c) Case III (d) Case IV
The rectangular slot in the ground plane can get the lowest
resonant frequency of 2.52 GHz. There are some L shaped
strips are added on the ground plane to get the middle resonant
frequency of 3.5 GHz. The addition of two slots
the S shaped symmetric parasitic elements provides the
highest resonance and makes impedance matching in the
wide band range. The L strips embedded on the rectangular
slot are used for feeding and providing the middle band
work.The initial length of slot embedded on the S shape
and L strip is approximated according to,
𝑙 = 𝜆𝑃4
= 𝑐
4𝑓 𝜀 , 𝜀 =
𝜀𝑟 + 1
2
where c is the speed of light in vacuum, f is the resonant
frequency, and εr is the relative permittivity of the
substrate.
The whole antenna is optimized with the commercial software CST
Microwave studio and values of some
optimized parameters are shown in table 1.
Table I: Dimensions of Proposed Antenna
Parameters L W Lg Wg Wf Lf W1
Dimension 30 30 30 30 3 16 11.4
Parameters W3 W6 W7 W8 L6 L5 L3
Dimension 0.3 8.5 13 0.27 6 5.5 16.5
Parameters L2 L8 LG2 Lg3 Lg4 Lg5 Lg1
Dimension 4.57 4 2.25 2.75 2.75 1.5 5.75
Parameters Lg9 Lg7 Wg1 Wg2 Wg3 Wg5 G1
Dimension 6.75 11.25 11 4 8.1 8.1 0.5
Fig. 3. Frequency versus return loss plot of different stages of
antenna.
The fig. 2 shows the various designing stages of the
proposed microstrip antenna and fig. 3 shows the
corresponding return loss plots. The simulated return loss
versus frequency curve for the designed single antenna is shown
in Fig. 4. The designed antenna resonates at 2.52
GHz, 3.47 GHz and 5.68 GHz respectively. The return loss
for 2.52 GHz is -30.24 dB, for 3.47 GHz is -32.09 dB and
the return loss for 5.68 GHz is -27.10 dB which covers the
minimum required value of return loss of -10 dB. The
bandwidth of the proposed patch antenna is 470 MHz (2.39
GHz – 2.86 GHz), 550 MHz (3.13 GHz – 3.68 GHz) for
3.47 GHz and 900 MHz (5.08 GHz – 5.97 GHz) for 5.68
GHz.
Fig. 4. Simulated Return loss curve of the proposed antenna.
-
International Journal of Electrical Electronics & Computer
Science Engineering
Volume 1, Issue 5 (October 2014), ISSN : 2348 2273
Available Online at www.ijeecse.com
3
Fig. 5. VSWR Plot of the proposed antenna.
The fig. 5 shows the simulated VSWR plot of the triple band
antenna and VSWR ratio at 2.52 GHz, 3.47 GHz and
5.27 GHz frequency is 1:1.06, 1:1.05 and 1:1.09
respectively.
Fig. 6. Current distribution of the proposed antenna (a) 2.52
GHz, (b) 3.47 GHz and (c) 5.68 GHz
The current distribution at different frequencies are
illustrated in fig. 6(a), 6(b) and 6(c), The fig. 6(a) shows
that the current distributes mainly along the edges of the
rectangular slot of the ground plane at 2.52 GHz. In figure
6(b) the current flowing along the two L strips embedded
in the ground plane at 3.47 GHz and in figure 6(c) the
current mainly concentrates in the slots provided in the
parasitic elements at 5.68 GHz.
III. INTEGRATION OF 2 x 1 MIMO ANTENNA
Fig.7 shows four common configurations of the
combination of two such antennas. The simulated S-
parameters of the MIMO/diversity configurations are
shown in Fig. 8. The proposed antenna provides good impedance
matching with slight variation and high
isolation between the two antenna ports without the use of
any external slot. It is seen that in the front-to-front
configuration, the value of S12 is completely below the -
10dB while in the other configurations the S12 goes above
the -10dB.
Fig. 7. MIMO/diversity triple-band configurations, (a)
front-to-front, (b) side by side, (c) orthogonal and (d)
parallel.
Fig. 8 Simulated S-Parameters of different configurations of
MIMO antenna
The simulated envelope correlation of the proposed
MIMO/ diversity triple-band configuration of the array
structures shown in Fig.7 is shown in Fig. 9. It is noticed
that all four configurations of the arrays, the
front-to-front
provide less than 0.05 envelope correlations.
Fig. 9. Simulated ECC of different configurations of MIMO
antenna.
IV. RESULTS AND DISCUSSION
(A) S- Parameters
Fig. 10. Simulated plots for the proposed MIMO antenna.
Examining the simulation results shown in Fig. 10, the return
loss plots S11 and S22 are approximately same, the
mutual coupling S12 and S21 are same. The overall
reflection coefficient considering S11 and S22 of -10 dB
criteria. There is a multiband response happening at various
groups of frequencies. These bands are marked as band 1
(2.37 GHz – 2.76 GHz), band 2 (3.15 GHz – 3.67 GHz),
and band 3 (4.99 GHz – 5.97 GHz). The bandwidths for
these bands are determined by the reflection coefficient
(S11 and S22) of -10 dB or lower. The bandwidths are 400
MHz, 520 MHz, and 980 MHz of the three bands
respectively. In band 1 the S11 and S22 is -21.01 dB, band 2 at
-31.06 dB and band 3 at -31.24 dB. In band 1 the mutual
coupling S12 and S21 is below -10.16 dB, band 2 at -13.70
dB and band 3 at -25.85 dB.
-
International Journal of Electrical Electronics & Computer
Science Engineering
Volume 1, Issue 5 (October 2014), ISSN : 2348 2273
Available Online at www.ijeecse.com
4
(B) VSWR
Fig. 11. Simulated VSWR Plot of MIMO antenna.
Fig. 11 shows the VSWR plot for the MIMO antenna and provide
VSWR of 1.19 for the lower band, 1.05 for the
middle band, and 1.05 for the upper band.
Radiation Pattern
Fig: 12, 13, 14 shows the simulated 3D radiation pattern, the
radiation pattern seems to be nearly omni-directional.
Fig. 12. 3D Radiation Pattern (2.49 GHz)
Fig. 13. 3D Radiation Pattern (3.45 GHz)
Fig. 14. 3D Radiation Pattern at 5.66 GHz
(C) Envelope Correlation Coefficient
Fig. 15. Envelope correlation vs. frequency for MIMO.
The ideal value of Envelope correlation coefficient (ρ)
should be less than 0.07 for a mobile base station. Then for
mobile terminals, the value for ρ should be 0.5 or less.
From the fig. 15 the ECC will be less than 0.05 for all the
operating frequencies.
Table II: Comparison of Simulated Antennas
Antenna Type
Frequency
Range
Return Loss
Band
Width
Gain
Single
Antenna
2.39 GHz-2.86 GHz
-30.24 dB
470 MHz
2.66 dB
3.10 GHz-3.68 GHz
-32.09 dB
550 MHz
3.02 dB
5.08 GHz-5.96 GHz
-27.10 dB
900 MHz
4.09 dB
MIMO
Antenna
2.37 GHz-2.76 GHz
-21.01 dB
400 MHz
3.58 dB
3.15 GHz-3.67 GHz
-31.06 dB
520 MHz
4.22 dB
4.99 GHz-5.96 GHz
-31.24 dB
980 MHz
7.06 dB
Table III shows a comparison of fabricated triple band MIMO
antenna and previously implemented triple band
MIMO antenna in [5-14]. The antennas designed in the
papers do not cover the WLAN (2.4/5.2/5.8),WiMAX
(2.5/3.5/5.5) and 2.6 GHz 4G LTE. The overall size of the
antenna reduced to 77 x 30 x 3.2 mm3 compared to the antennas
designed in [5-14].
Table III: Comparison with Existing Mimo Antennas
Ref. No: Dimensions
(mm3)
WLAN
(2.4/5.2/5.8)
WIMAX
(2.5/3.5/5.5)
4G
LTE
(2.6)
[5] 80x18x1.6 mm3 (2.4/5.8) (2.5/3.5/5.5) -
-
International Journal of Electrical Electronics & Computer
Science Engineering
Volume 1, Issue 5 (October 2014), ISSN : 2348 2273
Available Online at www.ijeecse.com
5
[6] 85x40x0.64 mm3 (2.4/5.2) (3.5) -
[7] 110x52x1.6 mm3 (2.4) (3.5/5.5) -
[8] 48.54x40x1.6 mm3 (5.2) (3.5) -
[9] 110x52x1.6 mm3 (2.4) (3.5/5.5) -
[10] 110x160x0.8 mm3 (2.4) (2.5) (2.6)
[11] 99x55x1.6 mm3 (2.4) (3.5) -
[12] 125x85x0.8 mm3 (2.4) (5.5) -
[13] 79x160x1.52 mm3 (2.4/5.2/5.8) (3.5) -
[14] 40x90x0.79 mm3 (2.4) (3.5) -
MIMO
Antenna 77x30x3.2 mm
3 2.4/5.2/5.8) (2.5/3.5/5.5) (2.6)
The images of the fabricated single antenna and Multiple
input multiple output antenna for Bluetooth, 4G
LTE,WLAN and WiMAX applications is shown in fig. 16, fig. 17 and
fig. 18. Fig. 19, Fig. 20, Fig. 21 shows the
comparison of simulated and measured results of single
antenna and Multiple input Multiple Output Antenna.
Fig. 16. Front view and Back view of fabricated SISO
Microstrip Antenna
Fig. 17 Front view of fabricated MIMO Microstrip Antenna
Fig. 18 Back view of fabricated MIMO Microstrip Antenna
Fig. 19. Simulated and Measured Return loss of the single
antenna.
Fig. 20. Simulated and Measured Return loss of the MIMO
antenna.
Fig. 21. Simulated and Measured Insertion loss of the MIMO
antenna.
V. CONCLUSION
In this work a compact microstrip slot antenna designed for a
triple band operation is presented. The proposed
antenna is composed of a ground plane on which a
rectangular slot is etched and a Pair of L strips embedded
in the slot and S shaped parasitic elements are added on
another side of the substrate that enables proper adjusting
of the resonant bands. The simulation results of the triple
band single antenna with bandwidths of 470 MHz (2.39
GHz - 2.86 GHz), 550 MHz (3.13 GHz - 3.68 GHz) and 900 MHz (5.08
GHz - 5.97 GHz) are obtained. Next, a
study was performed to implement the single antenna into
2x1 MIMO arrangements on the same circuit space. The
-
International Journal of Electrical Electronics & Computer
Science Engineering
Volume 1, Issue 5 (October 2014), ISSN : 2348 2273
Available Online at www.ijeecse.com
6
simulation results of the MIMO antenna with bandwidths
of 400 MHz (2.37 GHz - 2.76 GHz), 520 MHz (3.15 GHz -
3.67 GHz) and 980 MHz (4.99 GHz - 5.96 GHz) are
obtained and it shows that the MIMO antenna is suitable
for working in Bluetooth (2.4GHz – 2.5 GHz), 4G LTE (2.5 GHz –
2.69 GHz), WLAN (2.4/5.2/5.8 GHz), and
WiMAX (2.5/3.5/5.5 GHz) applications. Because of the
good electromagnetic property and compact size, the
antenna is competitive candidate for multiband wireless
communication applications. The proposed antenna can be
an excellent choice for Bluetooth, 4G LTE, WLAN and
WiMAX applications due to its small size, simple
structure, good multi-band characteristics, nearly
omnidirectional radiation pattern, better gain, better
mutual
coupling and better envelope correlation coefficient over
the three bands.
VI. REFERENCES
[1] Lin Dang, Zhen Ya Lei, Yong Jun Xie, Gao Li Ning, and Jun
Fan, "A Compact Microstrip Slot Triple-Band
Antenna for WLAN/WiMAX Applications", IEEE
Antennas and Wireless Propagation Letters,
Vol.9.2010.
[2] T. Wang, Y. Z. Yin, J. Yang, Y.L. Zhang, and J.J. Xie,
"Compact Triple-Band Antenna Using Defected
Ground Structure for WLAN/WIMAX Applications",
Progress In Electromagnetics Research Letters, Vol.
35,164, 2012.
[3] C.R. Byra Reddy, N.C. Easwar Reddy and C.S.
Sridhar, "A Compact Triple Band Rectangular
Microstrip Slot antenna for WLAN/WIMAX
applications", Journal of Theoretical and Applied
Information Technology, October 2011.
[4] Reza Karimian and Hamed Tadayon, "Multiband
MIMO Antenna System with Parasitic Elements for
WLAN and WiMAX Application", International
Journal of Antennas and Propagation, 2013.
[5] Ali Foudazi, Alireza Mallahzadeh, and Sajad
Mohammad Ali Nezhad, "A triple-band
WLAN/WiMAX printed monopole antenna for MIMO
applications", Microwave and Optical Technology
Letters, Vol. 54, No. 5, May 2012.
[6] A.R. Mallahzadeh, S.F. Seyyedrezaei, N.
Ghahvehchian, S. Mohammad ali nezhad and S.
Mallahzadeh,"Tri-Band Printed Monopole Antenna for
WLAN and WiMAX MIMO Systems", Proceedings of the 5th European
Conference on antennas and
propagation.
[7] Masoumeh Darvish and Hamid Reza Hassani, "Quad
band CPW-fed monopole antenna for MIMO applications", EuCAP
2012.
[8] R. lothi Chitra, B. Ramesh Karthik and V. Nagarajan,
"Double L -Slot Microstrip Patch antenna array for
WiMAX and WLAN", IEEE, 2012.
[9] Masoumeh Darvish and Hamid Reza Hassani,
"Multiband Uniplanar Monopole Antenna for MIMO
Applications", 20th Iranian Conference on Electrical
Engineering, May 2012.
[10] Xing Zhao and Jaehoon Choi, "Multiband MIMO
antenna for 4G Mobile Terminal", Asia-Paci_c
Microwave Conference Proceedings, 2013.
[11] Teng Guo, Dongya Shen, Wenping Ren and Xiupu
Zhang,"A High Isolation MIMO Antenna for WLAN
and WiMAX", IEEE 2013.
[12] Sultan Shoaib, Imran Shoaib, Nosherwan Shoaib,
Xiaodong Chen and Clive G. Parini, "Design and
Performance Study of a Dual-Element Multiband
Printed Monopole Antenna Array for MIMO
Terminals", IEEE Antennas and Wireless Propagation
Letters, vol. 13, 2014.
[13] Reza Karimian, Homayoon Oraizi, Senior Member, IEEE, Saeed
Fakhte, and Mohammad Farahani,
"Novel F-Shaped quad-band printed slot antenna for
WLAN and WiMAX MIMO Systems", IEEE
Antennas and wireless propagation letters, vol. 12,
2013.
[14] Chan Hwang See, Raed A. Abd-Alhameed, Zuhairiah Z. Abidin,
Neil J. McEwan, and Peter S.
Excell,"Wideband Printed MIMO/Diversity Monopole
Antenna for WiFi/WiMAX Applications", IEEE
Transactions on Antenna and Propagation, vol. 60,
NO. 4, April 2012.