Dual Polarization Reconfigurable Antenna.
DUAL POLARIZATION RECONFIGURABLE ANTENNA
NUR SHAHEERA ALIA BINTI SADICK ALI
This Report Is Submitted In Partial Fulfillment of the Requirements for the Bachelor
Degree in Electronic Engineering (Wireless Communication)
Faculty of Computer Engineering and Electronic Engineering.
Universiti Teknikal Malaysia Melaka
Jun 2015
ii
iii
DECLARATION
“I hereby admit that this report is my own work except that every such summaries
and excerpts only have me explain the source.”
Signature
:………………………………………
Name
: NUR SHAHEERA ALIA BINTI SADICK ALI
Date
:……………………………………….
iv
SUPERVISOR APPROVAL
"I acknowledge that I have read this work in my / THIS work is sufficient in scope
and quality for the award of a Bachelor of Electronic Engineering (Wireless
Communication).”
Signature
:………………………………………
Name
: DR. MOHAMAD ZOINOL ABIDIN BIN ABD AZIZ
Date
:……………………………………….
v
DEDICATION
Dedicated to my mother and my father with love and care.
vi
ACKNOWLEDGEMENT
First of all, thank to our creator, "ALLAH" for the continuous blessing and for give
me the strength and chances to complete this study.
I would like to express my appreciations to Dr. Mohamad Zoinol Abidin Bin Abd
Aziz for their advice during my research. As my supervisors, he has constantly
encouraged me to be in focus hardly towards achieving my goal. His observations
and comments helped me to establish the overall direction of the research and move
forward with in depth investigations.
I am extremely indebted to my family especially my parents for their endless love
and emotional support which has brought me this for in my life.
Finally, I would like to thank my classmate Norsatina Binti Mohd Kassim whose
have been a great help during the period of my study in UTeM.
vii
ABSTRACT
Multipath is a propagation phenomenon that results in radio signals reaching
the receiving antenna by two or more paths. The propagation delay along each path is
different. Multipath fading occurs in any environment where there is multipath
propagation and there is some movement of elements within the radio
communications system. By using dual polarization, it can increase system capacity
of traffic handling, combat multipath effect, enhance the system performance, and
increase channel capacity. The main objective of this project is to design, simulate
and fabricate the reconfigurable dual polarization antenna. The antenna should be
able to operate at the resonant frequency of 2.4GHz with the return loss of -10dB and
the polarization can be switch by using PIN diode. The antenna are design step by
step and start with linear polarization antenna, right-handed polarization antenna,
left-handed polarization antenna, dual polarization antenna and dual polarization
reconfigurable antenna. Then the design will simulate by using CST 2014. After the
design achieved project objective, the next step is fabrication process and
measurement process. The simulation and measurement result show that the design
antenna having the resonant frequency 2.4GHz and below than -10dB. The
directivity is more than 6dBi, the gain is more than 3dB and the total efficiency is
less than -3dB. This antenna able to produced dual polarization which is linear
polarization and right-hand circular polarization. From this project, prove that the
antenna design able to produce dual polarization reconfigurable antenna.
viii
ABSTRAK
Pelbagai laluan adalah fenomena di mana isyarat radio yang sampai pada
antenna penerima melalui dua atau lebih laluan. Kelewatan perambatan pada setiap
laluan adalah berbeza. Pemudaran pelbagai laluan berlaku pada persekitaran yang
mana ada perambatan pelbagai laluan dan terdapat pergerakan elemen di dalam
system radio komunikasi. Dua polarisasi dapat membantu meningkatkan kapasiti
system, menangani kesan pelbagai laluan, meningkatkan prestasis system, dan
meningkatkan
kapasiti
saluran.
Objektif
utama
projek
ini
adalah
untuk
merekabentuk, simulasi dan fabrikasi antena dwi polarisasi konfigur. Antena ini
boleh beroperasi pada frekuensi 2.4GHz dengan kehilangan pulangan -10dB dan
jenis polarisasi boleh tukar dengan menggunakan diod PIN. Antena ini direka
peringkat demi peringkat bermula dengan rekaan antena “linear” , antena “right-hand
circular” , antena “left-hand circular, antenna dwi polarisasi dan antena dwi
polarisasi konfigur.
Kemudian, kesemua antenna akan disimulasi menggunakan
perisian CST 2014. Selepas objektif merekebentuk tercapai, kesemua antenna
tersebut akan melaui proses fabrikasi dan proses pengukuran. Keputusan simulasi
dan ukuran menunjukan bahawa rekabentuk antenna tersebut mempunyai frekuensi
2.4GHz dan bawah dari -10dB. Nilai penumpuan adalah lebih dari 6dBi, nilai ‘gain’
melebihi 3dB dan jumah keseluruhan kecekapan adalah kurang daripada -3dB.
Antena ini mampu beroperasi dalam dua polarisasi. Dua polarisasi tersebut adalah
polarisasi “linear” dan polarisasi “right-hand circular”. Hasil daripada projek ini
menunjukan rekabentuk antenna tersebut mampu menghasilkan antena dwi polarisasi
konfigur.
ix
CONTENTS
CHAPTERS TITLE
I
PAGE
PROJECT TITLE
i
PROJECT APPROVE FORM
ii
DECLARATION
iii
SUPERVISOR APPROVAL
iv
DEDICATION
v
ACKNOWLEDGEMENT
vi
ABSTRACT
vii
ABSTRAK
viii
CONTENTS
ix
LIST OF FIGURES
xii
LIST OF TABLES
xiv
LIST OF ABBREVIATIONS
xvi
LIST OF APPENDICES
xvii
INTRODUCTION
1.1
Problem statement
2
1.2
Objective
4
1.3
Project scope
4
1.4
Project Methodology
5
x
II
LITERATURE REVIEW
2.1
Fading
7
2.2
Diversity
8
2.3
Polarization
9
2.4
Polarization of antenna
11
2.5
Reconfigurable antenna
12
2.6
Type of antenna reconfiguration
12
2.7
Reconfiguration techniques
13
2.8
Electrical reconfigurable antenna
2.8.1 Reconfigurable antenna based on RFMEMS
2.8.2 Reconfigurable antenna based on PIN
Diodes
2.8.3 Reconfigurable antenna based on
14
15
15
16
Varactors
III
2.9
Optically reconfigurable antenna
17
2.10
Physically reconfigurable antenna
17
2.11
PIN Diode
17
METHODOLOGY
3.1
Antenna design process
19
3.2
Design specification
22
3.3
Square Patch Linear Polarization Antenna
23
(Design 1)
3.4
Square Patch Circular Polarization Antenna
25
(Design 2)
3.5
Square Patch Dual Polarization Antenna
(Design 3)
26
xi
3.6
Square
Patch
Tri-Polarization
Antenna
27
(Design 4)
IV
3.7
Simulation process
28
3.8
Fabrication process
30
3.9
Measurement process
31
3.9.1 Return loss measurement
31
3.9.2 Radiation pattern measurement
32
3.9.3 Gain measurement
33
RESULT AND DISCUSSION
4.1
Square Patch Linear Polarization Antenna
35
(Design 1)
4.2
Square Patch Circular Polarization Antenna
40
(Design 2)
4.3
Square Patch Dual Polarization Antenna
44
(Design 3)
4.4
Square
Patch
Tri-Polarization
Antenna
52
(Design 4)
4.5
V
Data Comparison and Analyses
58
CONCLUSION AND FUTURE WORK
67
5.1 Conclusion
69
5.2 Future work
REFERENCES
70
APPENDICES
77
xii
LISTS OF FIGURES
No
Title
Page
1.1
Flow chart
6
2.1
Fading occur during multipath propagation
8
2.2
Type of diversity
9
2.3
Direction of polarization
10
2.4
Classification of polarization
11
2.5
Electric field of polarize
11
2.6
Type of antenna reconfiguration
13
2.7
Reconfiguration techniques
14
2.8
Different type of switch
14
2.9
PIN Diode
15
2.10
Equivalent circuit of PIN Diode
16
2.11
Varactor Diode
16
2.12
Equivalent circuit of varactor diode
16
2.13
PIN Diode BAR50-02V
18
3.1
Flow chart of design process
21
3.2
Antenna design of Design 1
23
3.3
Antenna design of Design 2
26
3.4
Antenna design of Design 3
27
3.5
Antenna design of Design 4
28
3.6
Condition of biasing circuit
29
3.7
Reconfiguration technique
29
3.8
Flow chart of fabrication process
30
3.9
Additional design of fabrication process
31
3.10
Network analyzer
32
xiii
3.11
Setup of anechoic chamber
32
3.12
Setup of gain measurement
34
4.1
Antenna design of Design 1
36
4.2
Simulation and measured return loss results of Design1
37
4.3
Radiation pattern results of Phi 0, Phi 90 and Theta 90
38
4.4
Antenna design of Design 2
40
4.5
Simulation and measured return loss results of Design2
41
4.6
Radiation pattern results of Phi 0, Phi 90 and Theta 90
43
4.7
Antenna design of Design 3
45
4.8
Simulation and measured return loss results of Design3
46
4.9
Radiation pattern results of Phi 0, Phi 90 and Theta 90
49
4.10
Antenna design of Design 4
52
4.11
Simulation and measured return loss results of Design4
53
4.12
Radiation pattern results of Phi 0, Phi 90 and Theta 90
55
4.13
Radiation pattern of Phi 0
60
4.14
Radiation pattern of Phi 90
62
4.15
Radiation pattern of Theta 90
64
xiv
LIST OF TABLES
No
Title
Page
3.1
Design specification
22
3.2
Characteristic of substrate
23
3.3
Optimum parameter of additional design
31
4.1
Optimum parameter of Design 1
36
4.2
Axial ratio, directivity, efficiency and gain results of
37
Design 1
4.3
Surface current results of Design 1
39
4.4
Optimum parameter of Design 2
41
4.5
Axial ratio, directivity, efficiency and gain results of
42
Design 2
4.6
Surface current results of Design 1
43
4.7
Optimum parameter of Design 3
45
4.8
Return loss and resonance frequency results of Design
47
3
4.9
Axial ratio, directivity and efficiency results of Design
47
3
4.10
Simulation and measured gain results of Design 3
48
4.11
Surface current results of Design 3A
49
4.12
Surface current results of Design 3B
51
4.13
Diode configuration of Design 4
52
4.14
Return loss and resonance frequency results of Design
53
4
4.15
Axial ratio, directivity and efficiency results of Design
54
xv
4
4.16
Simulation and measured gain results of Design 4
54
4.17
Surface current results of configuration S1 and S2
56
4.18
Surface current results of configuration S3 and S4
57
4.19
Phi 0
59
4.20
Phi 90
61
4.21
Theta 90
63
4.22
Comparison of resonance frequency, return loss, gain,
66
axial ratio, directivity and efficiencies of Design 4
xvi
LIST OF ABBREVATIONS
c
- Velocity of light in free space
L
- Length of the patch antenna
W
- Width of the patch antenna
Lg
-Length of ground
Wg
- Length of ground
ℰ�
-Effective relative permittivity
-Relative permittivity
ℰ�
- Desired resonant frequency
h
�
-Substrate thickness
Zo
- Characteristic of impedance
CST
- Computer Simulation Technology
xvii
LIST OF APPENDICES
No
Title
Page
A
BAR5-02V
77
B
Fabrication of antenna design
84
CHAPTER I
INTRODUCTION
This chapter is discussed about the introduction of the antenna design of dual
polarization of reconfigurable antenna. Moreover, this chapter also explains about
problem statement, objective and scope of work.
Nowadays, wireless communication are widely used. So it will increase the
demand of high data speed and data rate. Example of application that use wireless
communication are smartphone, laptop and etc. Wireless communication means
communication between two or more devices using a wireless signal in a long distance
through electromagnetic signal within the air. An antenna is one of the component that
use in wireless application. An antenna is a device used to transform an RF signal,
traveling on a conductor, into an electromagnetic wave in free space.
There are several type of antenna which is parabolic antenna, yagi-uda antenna,
monopole antenna, dipole antenna, horn antenna and etc. Every antenna have their
own capabilities and usage for different type of application. Each application have
their own specific frequency. For an examples frequency for UWB is 3.1GHz –
10.6GHz and frequency WLAN is 2.4GHz. All of the frequency are the standard
frequency that is provide from Federal Communication Commission (FCC). There are
seven antenna parameters that are used to measure antenna performances which is
radiation pattern, directivity, gain, efficiency, resonant frequency, return loss, and
antenna polarization.
This final year project will be study on polarization of antenna. Polarization is
divided into three main types. They are linear polarization, circular polarization and
2
elliptical polarization. In linear polarization it is divided into two polarization which is
vertical and horizontal polarization. Meanwhile circular polarization and elliptical
polarization have two polarization, right-handed and left-handed polarization. In
addition, an antenna only can communicate if have same polarization at both side,
transmitter and receiver.
1.1
Problem Statement
Wireless communication have been penetrating into our society and affecting our
everyday life profoundly during the last decade far beyond any earlier expectations.
The facility of information exchange using wireless communication system has
affected many aspect of the modern lifestyle. Increasing demand for high speed and
multimedia application drives wireless market to grow in an explosive rate in order to
deliver wireless data communication such as Internet access, as well as messaging,
video-conferencing and other high-speed data transmission application.
The time varying nature of the channel quality in wireless environment, knows as
fading. Fading is deviation of the attenuation affecting a signal over certain
transmission media. The fading may be varying with time, geographical position or
radio frequency. Fading can cause poor performance in a communication system
because it can result in a loss of signal power without reducing the power of the noise.
Multipath is a propagation phenomenon that results in radio signals reaching
the receiving antenna by two or more paths. The propagation delay along each path is
different. Multipath fading occurs in any environment where there is multipath
propagation and there is some movement of elements within the radio communications
system. It is also occur due to reflections and diffraction of radio waves on walls,
floors, objects, etc. The transmitted signal traverse in multiple path because of the
presence of reflectors in the environment surrounding at transmitter and receiver. The
superposition of the multiple copies of the transmitted will be seen at the receiver and
each of it will traversing at different path. While travelling from the source to the
receiver, each of signal copy will have differences of attenuation, delay and phase shift.
Then the interference seen at the receiver can be either constructive or destructive,
amplifying or attenuating the signal power. As a result the communication will be
3
temporary failure due to severe drop in the channel signal-to-noise ratio and it is known
as a deep fade which is strong destructive interference.
Diversity is a way to protect against deep fades, a choice to combat fading.
Diversity combats fading by providing the receiver with multiple uncorrelated replicas
of the same information bearing signal. Multipath fading may be minimized by
practices called polarization diversity. From a portable, a signal will varying and then
received at the base station. This is a polarization diversity based on high multipath
environments concept. When a signal traveling between the portable and base station
it will cause
mechanism of decorrelation for the different polarizations which is
multipath reflections. Each polarization are typically different when reflection
coefficient encountered. If one signal path go through a deep fade at a particular point
of time then another path may have a strong signal. When having more than one path
to select, both of the instantaneous and average signal-to-noise-ratio (SNR) can be
improved in the receiver by a large amount.
The polarization of an antenna is the radiated fields produced by an antenna
and evaluated in the far field. When do design of an antenna, polarization are important
to consider. The polarization of each antenna in a system should be appropriately
aligned. When both stations are using identical polarization maximum signal strength
between stations will occurs. A single polarized antenna will responds only to one
orientation of polarization either horizontal or vertical. By using dual polarization, it
can increase system capacity of traffic handling. For example, one of combination
transmitter/receiver are set on vertical polarization, while the second combination of
independent transmitter/receiver are set on horizontal polarization. The advantage of
using dual polarized is only use one antenna instead of using two antennas. An
improvement in uplink performance can be expected by using two receive antennas
with orthogonal polarizations and combining these signals.
Reconfigurable antenna also known as smart antenna is the antenna with the
special feature where the properties of the antenna can be change dynamically by
external control [7-12]. The properties of the antenna that can be change are
polarization, feed, resonant frequency and other. In this project, the polarization of the
antenna will be changed. Once these antennas are constructed and placed on a certain
4
platform, they can be reconfigured remotely without having to reconstruct the antenna
or the platform upon which the antenna structure is mounted.
1.2
Objective
Objective of this project is to design, simulate and fabricate dual polarization
reconfigurable antenna. The antenna design will be able to reconfigure the dual
polarization which is consisting of linear polarization, right-handed polarization and
left-handed polarization. Besides that, the antenna will be operating at the resonant
frequency of 2.4GHz. Next, the antenna design should meet the minimum requirement
where is the return loss of the antenna must be less than -10dB and gain more than
1dB.
1.3
Project scope
The scope of work for this project is divided into three parts. Firstly the antenna
will be design. The chosen design are linear polarization, circular polarization,
reconfigurable antenna and dual polarization reconfigurable antenna and will be
operate in frequency 2.4GHz where the return loss should be less than -10dB.
Secondly, the design of antenna will be simulate by using CST 2014 software and
observe the antenna parameter (return loss, gain and radiation pattern) and fabricate
by using FR4 substrate. The FR4 board having the substrate with dielectric constant,
Ɛr = 4.4, tangent loss, tanδ = 0.019, the thickness of the board is 1.6mm while the
thickness of the copper is 0.035mm. The material that used for fabrication is FR4
board by using the techniques of chemical etching technique. Lastly the fabricated
antenna will be measured by using signal generator, network analyzer and spectrum
analyzer and anechoic chamber.
5
1.4
Project Methodology
Figure 1.1 show the flow chart of this project. The project are started by doing
literature review on journals and books regarding the project. Next on the design
process, antenna that will be design are linear polarization, right-handed polarization,
left-handed polarization, dual polarization and reconfigurable dual polarization. After
that, the design will be simulate using CST 2014 software. If the result is not achieve
objective, the design process will be repeat again but if the design achieved desired
objective, proceed on the fabrication stage. After that, measurement will be made on
the fabricated antenna. The result of measurement antenna will compare with
simulation result. If the result are not equal, all the process need to repeat again but if
the result are equal the process are finish.
6
START
LITERATURE REVIEW
DESIGN PROCESS
Design dual polarization
reconfigurable antenna
NO
DESIGN
SIMULATION
YES
FABRICATION PROCESS
YES
NO
MEASUREMENT
PROCESS
END
Figure 1.1 Flow Chart
CHAPTER II
LITERATURE REVIEW
The literature review is one of the developer’s methodologies to enhance the
understanding of the field research for the developer. Besides that, literature reviews
are made for the support of the arguments that are made during this research. Apart
from that, the literature review is carried out in order to enable the reader to refer to
this section if there is confusion and misunderstanding of some of the terms that are
found throughout this research.
2.1
Fading
The explosive growth of wireless communication system has increase the
demand of enhances information accessibility and created a need of bandwidth
efficient communication techniques. Unfortunately, wireless communication channel
suffers from much impairment. One of them is fading, the deviation of attenuation
affecting a signal over certain transmission media. Multipath fading occurs in any
environment where there is multipath propagation and there is some movement of
elements within the radio communications system. In order to reduce fading problem
without use any cost of extra power or additional bandwidth, diversity are the
effective solution [3].
NUR SHAHEERA ALIA BINTI SADICK ALI
This Report Is Submitted In Partial Fulfillment of the Requirements for the Bachelor
Degree in Electronic Engineering (Wireless Communication)
Faculty of Computer Engineering and Electronic Engineering.
Universiti Teknikal Malaysia Melaka
Jun 2015
ii
iii
DECLARATION
“I hereby admit that this report is my own work except that every such summaries
and excerpts only have me explain the source.”
Signature
:………………………………………
Name
: NUR SHAHEERA ALIA BINTI SADICK ALI
Date
:……………………………………….
iv
SUPERVISOR APPROVAL
"I acknowledge that I have read this work in my / THIS work is sufficient in scope
and quality for the award of a Bachelor of Electronic Engineering (Wireless
Communication).”
Signature
:………………………………………
Name
: DR. MOHAMAD ZOINOL ABIDIN BIN ABD AZIZ
Date
:……………………………………….
v
DEDICATION
Dedicated to my mother and my father with love and care.
vi
ACKNOWLEDGEMENT
First of all, thank to our creator, "ALLAH" for the continuous blessing and for give
me the strength and chances to complete this study.
I would like to express my appreciations to Dr. Mohamad Zoinol Abidin Bin Abd
Aziz for their advice during my research. As my supervisors, he has constantly
encouraged me to be in focus hardly towards achieving my goal. His observations
and comments helped me to establish the overall direction of the research and move
forward with in depth investigations.
I am extremely indebted to my family especially my parents for their endless love
and emotional support which has brought me this for in my life.
Finally, I would like to thank my classmate Norsatina Binti Mohd Kassim whose
have been a great help during the period of my study in UTeM.
vii
ABSTRACT
Multipath is a propagation phenomenon that results in radio signals reaching
the receiving antenna by two or more paths. The propagation delay along each path is
different. Multipath fading occurs in any environment where there is multipath
propagation and there is some movement of elements within the radio
communications system. By using dual polarization, it can increase system capacity
of traffic handling, combat multipath effect, enhance the system performance, and
increase channel capacity. The main objective of this project is to design, simulate
and fabricate the reconfigurable dual polarization antenna. The antenna should be
able to operate at the resonant frequency of 2.4GHz with the return loss of -10dB and
the polarization can be switch by using PIN diode. The antenna are design step by
step and start with linear polarization antenna, right-handed polarization antenna,
left-handed polarization antenna, dual polarization antenna and dual polarization
reconfigurable antenna. Then the design will simulate by using CST 2014. After the
design achieved project objective, the next step is fabrication process and
measurement process. The simulation and measurement result show that the design
antenna having the resonant frequency 2.4GHz and below than -10dB. The
directivity is more than 6dBi, the gain is more than 3dB and the total efficiency is
less than -3dB. This antenna able to produced dual polarization which is linear
polarization and right-hand circular polarization. From this project, prove that the
antenna design able to produce dual polarization reconfigurable antenna.
viii
ABSTRAK
Pelbagai laluan adalah fenomena di mana isyarat radio yang sampai pada
antenna penerima melalui dua atau lebih laluan. Kelewatan perambatan pada setiap
laluan adalah berbeza. Pemudaran pelbagai laluan berlaku pada persekitaran yang
mana ada perambatan pelbagai laluan dan terdapat pergerakan elemen di dalam
system radio komunikasi. Dua polarisasi dapat membantu meningkatkan kapasiti
system, menangani kesan pelbagai laluan, meningkatkan prestasis system, dan
meningkatkan
kapasiti
saluran.
Objektif
utama
projek
ini
adalah
untuk
merekabentuk, simulasi dan fabrikasi antena dwi polarisasi konfigur. Antena ini
boleh beroperasi pada frekuensi 2.4GHz dengan kehilangan pulangan -10dB dan
jenis polarisasi boleh tukar dengan menggunakan diod PIN. Antena ini direka
peringkat demi peringkat bermula dengan rekaan antena “linear” , antena “right-hand
circular” , antena “left-hand circular, antenna dwi polarisasi dan antena dwi
polarisasi konfigur.
Kemudian, kesemua antenna akan disimulasi menggunakan
perisian CST 2014. Selepas objektif merekebentuk tercapai, kesemua antenna
tersebut akan melaui proses fabrikasi dan proses pengukuran. Keputusan simulasi
dan ukuran menunjukan bahawa rekabentuk antenna tersebut mempunyai frekuensi
2.4GHz dan bawah dari -10dB. Nilai penumpuan adalah lebih dari 6dBi, nilai ‘gain’
melebihi 3dB dan jumah keseluruhan kecekapan adalah kurang daripada -3dB.
Antena ini mampu beroperasi dalam dua polarisasi. Dua polarisasi tersebut adalah
polarisasi “linear” dan polarisasi “right-hand circular”. Hasil daripada projek ini
menunjukan rekabentuk antenna tersebut mampu menghasilkan antena dwi polarisasi
konfigur.
ix
CONTENTS
CHAPTERS TITLE
I
PAGE
PROJECT TITLE
i
PROJECT APPROVE FORM
ii
DECLARATION
iii
SUPERVISOR APPROVAL
iv
DEDICATION
v
ACKNOWLEDGEMENT
vi
ABSTRACT
vii
ABSTRAK
viii
CONTENTS
ix
LIST OF FIGURES
xii
LIST OF TABLES
xiv
LIST OF ABBREVIATIONS
xvi
LIST OF APPENDICES
xvii
INTRODUCTION
1.1
Problem statement
2
1.2
Objective
4
1.3
Project scope
4
1.4
Project Methodology
5
x
II
LITERATURE REVIEW
2.1
Fading
7
2.2
Diversity
8
2.3
Polarization
9
2.4
Polarization of antenna
11
2.5
Reconfigurable antenna
12
2.6
Type of antenna reconfiguration
12
2.7
Reconfiguration techniques
13
2.8
Electrical reconfigurable antenna
2.8.1 Reconfigurable antenna based on RFMEMS
2.8.2 Reconfigurable antenna based on PIN
Diodes
2.8.3 Reconfigurable antenna based on
14
15
15
16
Varactors
III
2.9
Optically reconfigurable antenna
17
2.10
Physically reconfigurable antenna
17
2.11
PIN Diode
17
METHODOLOGY
3.1
Antenna design process
19
3.2
Design specification
22
3.3
Square Patch Linear Polarization Antenna
23
(Design 1)
3.4
Square Patch Circular Polarization Antenna
25
(Design 2)
3.5
Square Patch Dual Polarization Antenna
(Design 3)
26
xi
3.6
Square
Patch
Tri-Polarization
Antenna
27
(Design 4)
IV
3.7
Simulation process
28
3.8
Fabrication process
30
3.9
Measurement process
31
3.9.1 Return loss measurement
31
3.9.2 Radiation pattern measurement
32
3.9.3 Gain measurement
33
RESULT AND DISCUSSION
4.1
Square Patch Linear Polarization Antenna
35
(Design 1)
4.2
Square Patch Circular Polarization Antenna
40
(Design 2)
4.3
Square Patch Dual Polarization Antenna
44
(Design 3)
4.4
Square
Patch
Tri-Polarization
Antenna
52
(Design 4)
4.5
V
Data Comparison and Analyses
58
CONCLUSION AND FUTURE WORK
67
5.1 Conclusion
69
5.2 Future work
REFERENCES
70
APPENDICES
77
xii
LISTS OF FIGURES
No
Title
Page
1.1
Flow chart
6
2.1
Fading occur during multipath propagation
8
2.2
Type of diversity
9
2.3
Direction of polarization
10
2.4
Classification of polarization
11
2.5
Electric field of polarize
11
2.6
Type of antenna reconfiguration
13
2.7
Reconfiguration techniques
14
2.8
Different type of switch
14
2.9
PIN Diode
15
2.10
Equivalent circuit of PIN Diode
16
2.11
Varactor Diode
16
2.12
Equivalent circuit of varactor diode
16
2.13
PIN Diode BAR50-02V
18
3.1
Flow chart of design process
21
3.2
Antenna design of Design 1
23
3.3
Antenna design of Design 2
26
3.4
Antenna design of Design 3
27
3.5
Antenna design of Design 4
28
3.6
Condition of biasing circuit
29
3.7
Reconfiguration technique
29
3.8
Flow chart of fabrication process
30
3.9
Additional design of fabrication process
31
3.10
Network analyzer
32
xiii
3.11
Setup of anechoic chamber
32
3.12
Setup of gain measurement
34
4.1
Antenna design of Design 1
36
4.2
Simulation and measured return loss results of Design1
37
4.3
Radiation pattern results of Phi 0, Phi 90 and Theta 90
38
4.4
Antenna design of Design 2
40
4.5
Simulation and measured return loss results of Design2
41
4.6
Radiation pattern results of Phi 0, Phi 90 and Theta 90
43
4.7
Antenna design of Design 3
45
4.8
Simulation and measured return loss results of Design3
46
4.9
Radiation pattern results of Phi 0, Phi 90 and Theta 90
49
4.10
Antenna design of Design 4
52
4.11
Simulation and measured return loss results of Design4
53
4.12
Radiation pattern results of Phi 0, Phi 90 and Theta 90
55
4.13
Radiation pattern of Phi 0
60
4.14
Radiation pattern of Phi 90
62
4.15
Radiation pattern of Theta 90
64
xiv
LIST OF TABLES
No
Title
Page
3.1
Design specification
22
3.2
Characteristic of substrate
23
3.3
Optimum parameter of additional design
31
4.1
Optimum parameter of Design 1
36
4.2
Axial ratio, directivity, efficiency and gain results of
37
Design 1
4.3
Surface current results of Design 1
39
4.4
Optimum parameter of Design 2
41
4.5
Axial ratio, directivity, efficiency and gain results of
42
Design 2
4.6
Surface current results of Design 1
43
4.7
Optimum parameter of Design 3
45
4.8
Return loss and resonance frequency results of Design
47
3
4.9
Axial ratio, directivity and efficiency results of Design
47
3
4.10
Simulation and measured gain results of Design 3
48
4.11
Surface current results of Design 3A
49
4.12
Surface current results of Design 3B
51
4.13
Diode configuration of Design 4
52
4.14
Return loss and resonance frequency results of Design
53
4
4.15
Axial ratio, directivity and efficiency results of Design
54
xv
4
4.16
Simulation and measured gain results of Design 4
54
4.17
Surface current results of configuration S1 and S2
56
4.18
Surface current results of configuration S3 and S4
57
4.19
Phi 0
59
4.20
Phi 90
61
4.21
Theta 90
63
4.22
Comparison of resonance frequency, return loss, gain,
66
axial ratio, directivity and efficiencies of Design 4
xvi
LIST OF ABBREVATIONS
c
- Velocity of light in free space
L
- Length of the patch antenna
W
- Width of the patch antenna
Lg
-Length of ground
Wg
- Length of ground
ℰ�
-Effective relative permittivity
-Relative permittivity
ℰ�
- Desired resonant frequency
h
�
-Substrate thickness
Zo
- Characteristic of impedance
CST
- Computer Simulation Technology
xvii
LIST OF APPENDICES
No
Title
Page
A
BAR5-02V
77
B
Fabrication of antenna design
84
CHAPTER I
INTRODUCTION
This chapter is discussed about the introduction of the antenna design of dual
polarization of reconfigurable antenna. Moreover, this chapter also explains about
problem statement, objective and scope of work.
Nowadays, wireless communication are widely used. So it will increase the
demand of high data speed and data rate. Example of application that use wireless
communication are smartphone, laptop and etc. Wireless communication means
communication between two or more devices using a wireless signal in a long distance
through electromagnetic signal within the air. An antenna is one of the component that
use in wireless application. An antenna is a device used to transform an RF signal,
traveling on a conductor, into an electromagnetic wave in free space.
There are several type of antenna which is parabolic antenna, yagi-uda antenna,
monopole antenna, dipole antenna, horn antenna and etc. Every antenna have their
own capabilities and usage for different type of application. Each application have
their own specific frequency. For an examples frequency for UWB is 3.1GHz –
10.6GHz and frequency WLAN is 2.4GHz. All of the frequency are the standard
frequency that is provide from Federal Communication Commission (FCC). There are
seven antenna parameters that are used to measure antenna performances which is
radiation pattern, directivity, gain, efficiency, resonant frequency, return loss, and
antenna polarization.
This final year project will be study on polarization of antenna. Polarization is
divided into three main types. They are linear polarization, circular polarization and
2
elliptical polarization. In linear polarization it is divided into two polarization which is
vertical and horizontal polarization. Meanwhile circular polarization and elliptical
polarization have two polarization, right-handed and left-handed polarization. In
addition, an antenna only can communicate if have same polarization at both side,
transmitter and receiver.
1.1
Problem Statement
Wireless communication have been penetrating into our society and affecting our
everyday life profoundly during the last decade far beyond any earlier expectations.
The facility of information exchange using wireless communication system has
affected many aspect of the modern lifestyle. Increasing demand for high speed and
multimedia application drives wireless market to grow in an explosive rate in order to
deliver wireless data communication such as Internet access, as well as messaging,
video-conferencing and other high-speed data transmission application.
The time varying nature of the channel quality in wireless environment, knows as
fading. Fading is deviation of the attenuation affecting a signal over certain
transmission media. The fading may be varying with time, geographical position or
radio frequency. Fading can cause poor performance in a communication system
because it can result in a loss of signal power without reducing the power of the noise.
Multipath is a propagation phenomenon that results in radio signals reaching
the receiving antenna by two or more paths. The propagation delay along each path is
different. Multipath fading occurs in any environment where there is multipath
propagation and there is some movement of elements within the radio communications
system. It is also occur due to reflections and diffraction of radio waves on walls,
floors, objects, etc. The transmitted signal traverse in multiple path because of the
presence of reflectors in the environment surrounding at transmitter and receiver. The
superposition of the multiple copies of the transmitted will be seen at the receiver and
each of it will traversing at different path. While travelling from the source to the
receiver, each of signal copy will have differences of attenuation, delay and phase shift.
Then the interference seen at the receiver can be either constructive or destructive,
amplifying or attenuating the signal power. As a result the communication will be
3
temporary failure due to severe drop in the channel signal-to-noise ratio and it is known
as a deep fade which is strong destructive interference.
Diversity is a way to protect against deep fades, a choice to combat fading.
Diversity combats fading by providing the receiver with multiple uncorrelated replicas
of the same information bearing signal. Multipath fading may be minimized by
practices called polarization diversity. From a portable, a signal will varying and then
received at the base station. This is a polarization diversity based on high multipath
environments concept. When a signal traveling between the portable and base station
it will cause
mechanism of decorrelation for the different polarizations which is
multipath reflections. Each polarization are typically different when reflection
coefficient encountered. If one signal path go through a deep fade at a particular point
of time then another path may have a strong signal. When having more than one path
to select, both of the instantaneous and average signal-to-noise-ratio (SNR) can be
improved in the receiver by a large amount.
The polarization of an antenna is the radiated fields produced by an antenna
and evaluated in the far field. When do design of an antenna, polarization are important
to consider. The polarization of each antenna in a system should be appropriately
aligned. When both stations are using identical polarization maximum signal strength
between stations will occurs. A single polarized antenna will responds only to one
orientation of polarization either horizontal or vertical. By using dual polarization, it
can increase system capacity of traffic handling. For example, one of combination
transmitter/receiver are set on vertical polarization, while the second combination of
independent transmitter/receiver are set on horizontal polarization. The advantage of
using dual polarized is only use one antenna instead of using two antennas. An
improvement in uplink performance can be expected by using two receive antennas
with orthogonal polarizations and combining these signals.
Reconfigurable antenna also known as smart antenna is the antenna with the
special feature where the properties of the antenna can be change dynamically by
external control [7-12]. The properties of the antenna that can be change are
polarization, feed, resonant frequency and other. In this project, the polarization of the
antenna will be changed. Once these antennas are constructed and placed on a certain
4
platform, they can be reconfigured remotely without having to reconstruct the antenna
or the platform upon which the antenna structure is mounted.
1.2
Objective
Objective of this project is to design, simulate and fabricate dual polarization
reconfigurable antenna. The antenna design will be able to reconfigure the dual
polarization which is consisting of linear polarization, right-handed polarization and
left-handed polarization. Besides that, the antenna will be operating at the resonant
frequency of 2.4GHz. Next, the antenna design should meet the minimum requirement
where is the return loss of the antenna must be less than -10dB and gain more than
1dB.
1.3
Project scope
The scope of work for this project is divided into three parts. Firstly the antenna
will be design. The chosen design are linear polarization, circular polarization,
reconfigurable antenna and dual polarization reconfigurable antenna and will be
operate in frequency 2.4GHz where the return loss should be less than -10dB.
Secondly, the design of antenna will be simulate by using CST 2014 software and
observe the antenna parameter (return loss, gain and radiation pattern) and fabricate
by using FR4 substrate. The FR4 board having the substrate with dielectric constant,
Ɛr = 4.4, tangent loss, tanδ = 0.019, the thickness of the board is 1.6mm while the
thickness of the copper is 0.035mm. The material that used for fabrication is FR4
board by using the techniques of chemical etching technique. Lastly the fabricated
antenna will be measured by using signal generator, network analyzer and spectrum
analyzer and anechoic chamber.
5
1.4
Project Methodology
Figure 1.1 show the flow chart of this project. The project are started by doing
literature review on journals and books regarding the project. Next on the design
process, antenna that will be design are linear polarization, right-handed polarization,
left-handed polarization, dual polarization and reconfigurable dual polarization. After
that, the design will be simulate using CST 2014 software. If the result is not achieve
objective, the design process will be repeat again but if the design achieved desired
objective, proceed on the fabrication stage. After that, measurement will be made on
the fabricated antenna. The result of measurement antenna will compare with
simulation result. If the result are not equal, all the process need to repeat again but if
the result are equal the process are finish.
6
START
LITERATURE REVIEW
DESIGN PROCESS
Design dual polarization
reconfigurable antenna
NO
DESIGN
SIMULATION
YES
FABRICATION PROCESS
YES
NO
MEASUREMENT
PROCESS
END
Figure 1.1 Flow Chart
CHAPTER II
LITERATURE REVIEW
The literature review is one of the developer’s methodologies to enhance the
understanding of the field research for the developer. Besides that, literature reviews
are made for the support of the arguments that are made during this research. Apart
from that, the literature review is carried out in order to enable the reader to refer to
this section if there is confusion and misunderstanding of some of the terms that are
found throughout this research.
2.1
Fading
The explosive growth of wireless communication system has increase the
demand of enhances information accessibility and created a need of bandwidth
efficient communication techniques. Unfortunately, wireless communication channel
suffers from much impairment. One of them is fading, the deviation of attenuation
affecting a signal over certain transmission media. Multipath fading occurs in any
environment where there is multipath propagation and there is some movement of
elements within the radio communications system. In order to reduce fading problem
without use any cost of extra power or additional bandwidth, diversity are the
effective solution [3].