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UNIVERSJTI TEKNIKAL MALAYSIA MELAKA
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
MINKOWSKI FRACTAL PATCH ANTENNA
FOR Wi-Fi APPLICATION
This report submitted in accordance with the requirement of the Universiti
Teknikal Malaysia Melaka (UTeM) for the Bachelor's Degree in Electronics
Engineering Technology (Telecommunications) with Honours
by
AMIRA ELEZA BINTI AZEMI
B071110126
890830-04-5222
FACULTY OF ENGINEERING TECHNOLOGY
2015
© Universiti Teknikal Malaysia Melaka
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UNIVERSITI TEKNIKAL MALAYSIA MELAKA
BORANG PENGESAHAN STATUS LAPORAN PROJEK SARJANA MUDA
TAJ UK: Minkowski Fractal Patch Antenna for Wi-Fi Application
SESI PENGAJIAN: 2014/15Semester1
Saya Amira Eleza Binti Azemi
mengaku membenarkan Laporan PSM ini disimpan di Perpustakaan Universiti Teknikal Malaysia Melaka (UTeM) dengan syarat-syarat kegunaan seperti berikut:
1. Laporan PSM adalah hak milik Universiti Teknikal Malaysia Melaka dan penulis. 2. Perpustakaan Universiti Teknikal Malaysia Melaka dibenarkan membuat salinan
untuk tujuan pengajian sahaja dengan izin penulis. 3. Perpustakaan dibenarkan membuat salinan laporan PSM ini sebagai bahan
pertukaran antara institusi pengajian tinggi. 4 . **Sila tandakan ( ../)
D
D D
SULIT
TERHAD
TIDAK TERHAD
(Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia sebagaimana yang termaktub dalam AKTA RAHSIA RASMI 1972)
(Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasi/badan di mana penyelidikan dijalankan)
Di;{ Cop Rasmi:
Kubang Paya Pauh, 02600 Arau , NlrRlJ AL M Bi· HASS:r .
Perl is. dO,t<>r: fg~ '101ogi ·~'ddll' Pllt ro,1'-l " · , tn~ ~ •
<.i•ulr ~el(rtOl{)g• ~.epJr · ter,foo · ~~.-, . i fcr.i .. UM<o1J~,1<1 \:~J
Tarikh: :l.6 , 0 I · '2 G 15
** Jika Laporan PSM ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/ organisasi berkenaan dengan menyatakan sekali sebab dan tempoh laporan PSM ini perlu dikelaskan sebagai SULIT atau TERHAD.
© Universiti Teknikal Malaysia Melaka
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DECLARATION
I hereby, declared this report entitled "Minkowski Fractal Patch Antenna
For Wi-Fi Application" is the results of my own research except as cited in
references.
Signature ···········~································ · Author' s Name Amira Eleza Binti Azemi
Date 16 .01 . io\s
© Universiti Teknikal Malaysia Melaka
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APPROVAL
This report is submitted to the Faculty of Engineering Technology of UTeM as a
partial fulfillment of the requirements for the degree of Bachelor of Electronic
Engineering Technology (Telecommunication) with Honours. The member of
the supervisory is as follow:
onJl ....... t).~~···················
(NURULHALIM BIN HASSIM)
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ABSTRACT
This report elaborated on the theories and techniques in the process of shrinking the
size of an antenna through the usage of fractals. The Minkowski fractal patch
antenna was investigated. The Minkowski fractal patch antenna was introduced in
order to reduce the size of antenna using miniaturization technique. This project
presented the design of fractal patch antenna based on the basic structure of square
antenna operating at 2.45GHz for Wi-Fi application. The fractal design was
introduced into the basic structure for the purpose of reducing the size of the
elements. Thus, an expectation would be set on the miniaturization to be achieved.
Simulations wave performed on several sets of the structures design using Computer
Simulation Technology Software . The simulation result showed that the fractal
iteration and the iteration factor had different effects on the reduction of the patch
antenna. From the experiment, the result showed that the 1st and znd iteration
Minkowski fractal patch antenna managed to reduce the antenna size, while
maintained the same resonant frequency as that of the normal square patch antenna.
Fractal antennas can obtain radiation pattern and input impedance_ similar to a longer
antenna, yet take less special area due to the many contours of the shape. Fractal
antenna is a fairly new research area and more likely to have a promising future
when used and designed into whole other applications.
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ABSTRAK
Laporan ini mengulas mengenai teori dan teknik dalam proses mengecilkan saiz
antena menggunakan pembahagian atau pecahan kepada bahagian-bahagian kecil
melalui fraktal . Di dalam laporan ini, antena Minkowski akan dikaji. Antena
Minkowski diperkenalkan bagi mengurangkan saiz dengan mengunakan teknik
pengecilan. Projek ini menunjukkan corak lakaran atau rekaan antena yang
mengandungi pembahagian kecil yang asalnya adalah antena segiempat sama yang
beroperasi pada frekuensi 2.45 GHz untuk aplikasi Wi-Fi. Corak pada fraktal ini
diperkenalkan kepada struktur asas untuk mengurangkan saiz pada elemen-elemen
tersebut. Oleh itu, pengecilan saiz antena akan dicapai. Lakaran struktur antena
dapat dilihat dengan menggunakan perisian CST (Computer Simulation
Technology). Keputusan simulasi menunjukkan pecahan kepada bahagian-bahagian
kecil dan faktor pembahagian memberi kesan yang berlainan kepada pengecilan saiz
antena. Daripada eksperimen yang telah dijalankan, keputusan menunjukkan pecahan
kepada bahagian kecil bagi peringkat pertama dan kedua akan mengurangkan saiz
antena disamping mengekalkan frekuensi resonan seperti anten~ segiempat sama.
Fraktal antena ini berjaya mendapatkan corak radiasi dan penentangan litaran
elektrik terhadap pengaliran kuasa elektrik yang sama dengan antena asal tetapi
mengambil kawasan yang kurang dengan bentuk kontur. Fraktal antena adalah
penyelidikan yang agak baru dan dijangka akan memberi masa depan yang cerah
untuk pelbagai aplikasi.
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DEDICATION
To my dearest mother, father and my family for
their continuous encouragement and support.
"You are my inspiration to strive for excellence"
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ACKNOWLEDGEMENT
Let me start by giving my gratitude to the one and only AJlah the Almighty
who with His insight and blessing has been a beacon to guide me on my journey in
finishing this report.
My sincerest appreciation and heartfelt recognition towards my honorable
supervisor, Mr. Nurulhalim Bin Hassim for assisting me in understanding the
fundamental of antenna that inspired me to make this work a success, as well for his
valuable and priceless experiences and wisdom. I greatly appreciate his assistance
and support during the completion of this report. I would also like to extend my
gratitude to my co-supervisor Mr Abdul Halim Bin Dahalan for all the inputs and
aids in developing my practical skills as well as providing the overall concept for the
thesis.
I would like to show my gratefulness to the wannth and encouragement that I
was at pleasure of receiving from my beloved father, En. Azemi Bin Zakaria, my
beloved mother, Pn. Chik Binti Isa and also all my family members throughout the
duration of my project. Without their love and patience, I would not be able to go
through the tough times experience in the process of making this report. A special
mention also for my wonderful acquaintance, Hafiz Aizat Bin Hazli for his never
ending supports and the internal and external motivation that has been provided, as
well as his earnest efforts in ensuring this project to come to fruition. Finally, my
gratitude is directed towards my mentor Mr. Nornikman Bin Hassan for his
contribution of ideas that had been provided regarding the theories behind the
antenna and also for the meetings and sessions that were conducted. I simply would
not be able to proceed if not for his kind and compassionate tutoring. Last but not
least, I would also like to give my thanks to whoever has assisted me in the process
of completing this report.
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TABLE OF CONTENT
CHAPTER ITEM PAGE
PROJECT TITLE
ABSTRACT iii
ABSTRAK iv
DEDICATION v
ACKNOWLEDGEMENT vi
TABLE OF CONTENT vii
LIST OF TABLES xiii
LIST OF FIGURES xiv
LIST OF ABBREVIATION xvii
LIST OF SYMBOLS xviii
1 INTRODUCTION
1.1 Brief Technical Overview 1
1.1.1 Wi-Fi Introduction
1.2 Objective 2
1.3 Problem Statement 2
1.3.1 Introduction 2
1.3.2 Solution Overview 3
1.4 Work Scopes 4
1.5 Project Methodology 5
1.5.1 Work Flow Description 6
1.6 Report Structure 7
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2 LITERATURE REVIEW
2.1 Introduction to Wi-Fi 8
2.1.1 Wi-Fi standards 9
2.1.2 Frequency Range 12
2.1.3 Benefits ofWi-Fi 12
2.1.3.l Wireless Ethernet 12
2.1.3.2 Extended Reach 12
2.1.3 .3 Cost Reduction 13
2.1.3.4 Mobility 13
2.1.3 .5 Flexibility 13
2.1.4 Applications For Wi-Fi 13
2.1.4.1 Internet Sharing Devices 13
2.1.4.2 Wireless Printers or Scanners 14
2.1.4.3 Video Streaming 14
2.2 Introduction of Antenna 15
2.3 Antenna Theory 15
2.4 Types of Antennas 16
2.4.1 Antenna Characteristic 16
2.4.2 Parameters of Antenna 16
2.4.2. l Radiation Pattern 16
2.4.2.2 Return Loss 18
2.4.2.3 Voltage Standing Wave Ratio 18
2.4.2.4 Bandwidth 19
2.4.2.5 Gain 20
2.4.2.6 Directivity 21
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2.4.2.7 Efficiency 22
2.4.2.8 Beamwidth 22
2.4.2.9 Polarization 23
2.5 Fractal Antenna 23
2.5.1 Introduction 23
2.5.2 Fractal Geometry 24
2.5.3 Fractal Advantages 24
2.6 Microstrip Antennas 25
2.6.1 Introduction ofMicrostrip Antennas 25
2.6.2 Basic of Microstrip Antennas 25
2.6.3 Advantages and disadvantages of Microstrip Antennas
2.7 Feeding Technique
2. 7.1 Microstrip Line Feed
2.7.2 Coaxial Feed
2.7.3 Aperture Couple Feed
2.7.4 Proximity Coupled Feed
2.7.5 Comparison of Feeding Methods
2.8 The Minkowski Fractal
2.8.1 Introduction
2.8.2 Design Consideration for Minkowski
27
31
32
33
34
35
36
37
37
Fractal Patch Antenna 39
2.8.2. l Substrate Selection 39
2.8.2.2 Element Width and Length 40
2.8.2.3 Design Consideration for
Minkowski Patch Geometry 42
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3 PROJECT METHODOLOGY
3.1 Project Methodology 43
3 .2 Theoretical Development 44
3.2.1 Performance Requirements 44
3.2.2 Fractal Antenna Patterns 45
3.2.3 Implementation Considerations 45
3.3 Design the Minkowski Fractal Patch antenna 46
3.3.1 Substrate Selection 46
3.3 2 Design the Minkowski Fractal Patch Antenna 46
3 .3 .2.1 Calculation on Square Patch Antenna 46
3.3.2.2 Calculation on 1st Iteration Minkowski
Fractal Patch Antenna 48
3 .3 2.3 Calculation on znd Iteration Minkowski
Fractal Patch Antenna 48
3.4 Design the Minkowski Fractal Patch Geometry 49
3.4 1 Design a rnicrostrip patch antenna with the
following parameters
3.4.2 Design Equations
3.4.3 Theoretical Formula
3.4.3.1 Square Patch Minkowski Fractal
Antenna (Calculation)
3.4.3.2 1st Iteration Minkowski Fractal
Antenna (Calculation)
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3.4.3.3 znd Iteration Minkowski Fractal
Antenna (Calculation) 51
3.4.4 Optimization 52
3.4.4.l Square Patch Minkowski Fractal
Antenna (Optimized) 52
3 .4.4.2 1st Iteration Minkowski Fractal Antenna
Antenna (Optimized) 53
3.4.4.3 znd Iteration Minkowski Fractal Antenna
Antenna (Optimized) 54
3.5 Experimental Setup 55
3.5. l Simulation Process 55
3.5.2 Fabrication Method 55
3.5.3 Measurement Process 57
3.6 Experimental Testing 58
3.6.1 Antenna Resonance Testing 59
3. 7 Gantt Chart 60
4 RES UL TS AND DISCUSSION
4.1 Simulation Result 61
4.1.l Square Microstrip Patch Antenna (Optimized) 61
4.1.2 1st Iteration Minkowski Fractal
Antenna (Optimized) 64
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4.1.3 2nd Iteration Minkowski Fractal
Antenna (Optimized) 66
4.2 Measurement Result 68
4.2.1 Square Microstrip Patch Antenna 68
4.2.2 1st Iteration Minkowski Fractal Antenna 69
4.2.3 2°d Iteration Minkowski Fractal Antenna 70
4.3 Discussion 71
5 CONCLUSION AND FUTURE WORKS
5.1 Conclusion
5.2 Future Works
REFERENCES
APPENDIX A
APPENDIXB
APPENDIXC
APPENDIXD
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NO
Table 2.1
Table 2.2
Table 2.3
Table 2.4
Table 3.1
Table 3.2
Table 3.3
Table 3.4
Table 4.1
Table 4.2
LIST OF TABLES
TITLE PAGE
Summary of the various Wi-Fi offerings 11
Advantages and disadvantages of microstrip antenna 28
Comparison of feeding methods 36
Material properties 40
Calculation valu~ and optimization value 55
Parametric study of width and length of the antenna 56
Project planning for psm 1 60
Project planning for psm 2 60
Comparison between simulation and measurements
result
Comparison of gain and return loss between simulation
and measurements result
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LIST OF FIGURES
NO TITLE PAGE
Figure 1.1 Methodology Flow Chart 6
Figure 2.1 Logo of Hardware devices certified by the Wi-Fi Alliance 9
Figure 2.2 Radiation lobes and beam widths of antenna pattern 17
Figure 2.3 Linear plots of power pattern and its associated lobes and
beam width 17
Figure 2.4 Antenna bandwidth in respect to return loss measurement 20
Figure 2.5 Beamwidth pattern of an antenna 22
Figure 2.6 Shapes of microstrip patch antenna 26
Figure 2.7 Basic Structure of microstrip 27
Figure 2.8 Microstrip feed (line feed) 32
Figure 2.9 Probe fed Rectangular Microstrip Patch Antenna (Coaxial Feed) 33
Figure 2.10 Aperture coupled feed 34
Figure 2.11 Proximity-coupled Feed 35
Figure 2.12 Zero, 1st and znd iteration Minkowski fractal microstrip
antennas 38
Figure 2.13 The Antennas Structures 42
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Figure 3.1
Figure 3.2
Figure 3.3
Figure 3.4
Figure 3.5
Figure 3.6
Figure 3.7
Figure 3.8
Figure 3.9
Figure 3.10
Figure 3.11
Figure 3.12
Figure 4.1
Figure 4.2
Figure 4.3
Figure 4.4
Figure 4.5
Figure 4.6
Figure 4.7
Figure 4.8
Figure 4.9
Square Patch Antenna (Calculation)
1st Iteration Minkowski Fractal Antenna (Calculation)
znd Iteration Minkowski Fractal Antenna (Calculation)
Square Patch Antenna (Optimized)
1st Iteration Minkowski Fractal Antenna (Optimized)
znd Iteration Minkowski Fractal Antenna (Optimized)
The flow of fabrication process
Machine for fabrication process
Return Loss Measurement Setup
Gain Measurement Setup
Radiation Pattern Measurement Setup
Experimental setup for antenna return
loss measurements
Return loss of the square microstrip patch antenna
Bandwidth for square microstrip patch antenna
The S-Parameter Smith Chart of the square microstrip
patch antenna
3D Radiation Pattern of the square microstrip patch
2D Radiation Pattern of the square microstrip patch antenna
Return loss of the first Iteration Minkowski Fractal Antenna
(Optimized)
Bandwidth for first iteration Minkowski fractal patch antenna
3 D Radiation Pattern of the first Iteration Minkowski
Fractal Antenna (Optimized)
2D Radiation Pattern of the first Iteration
Minkowski Fractal Antenna (Optimized)
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51
52
53
54
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61
62
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Figure 4.10 Return loss of the second Iteration Minkowski Fractal Antenna
(Optimized) 66
Figure 4.11 Bandwidth for second iteration Minkowski fractal
patch antenna 66
Figure 4.12 3D Radiation Pattern of the second Iteration Mink:owski Fractal Antenna(Optimized) 67
Figure 4.13 2D Radiation Pattern of the second Iteration Minkowski Fractal Antenna (Optimized) 67
Figure 4.14 Return loss of the square microstrip patch antenna 68
Figure 4.15 Radiation Pattern of the square microstrip patch antenna 68
Figure 4.16 Return loss of the 1 strteration microstrip patch antenna 69
Figure 4.17 Radiation Pattern of the 1st Iteration microstrip
patch antenna 69
Figure 4.18 Return loss of the zndlteration microstrip
patch antenna 70
Figure 4.19 Radiation Pattern of the znd Iteration microstrip
patch antenna 70
Figure 4.20 Construction of Minkowski Fractal
Patch Antenna 71
Figure 4.21 Simulation and measurement return loss of
Minkowski fractal patch antenna 73
Figure 4.22 Radiation pattern for the second iteration
minkowski patch antenna in 3D 74
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LIST OF ABBREVIATION
ABBREVIATION
CST
IEEE
FR4
SMA
VSWR
BW
HPBW
OFDM
HT
MIMO
FEC
RL
RF
20
30
WLAN
Wi-Fi
DESCRIPTION
Computer Simulation Technology
Institute of Electrical and Electronics Engineers
Flame Retardant 4
SubMiniature version A
Voltage Standing Wave Ratio
Bandwidth
Half Power Beam width
Orthogonal frequency-division multiplexing
High Throughput
Multiple input/multiple output
Forward error correction
Return Loss
Radio Frequency
2 Dimensional
3 Dimensional
Wireless Local Area Network
Wireless Fidelity
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SYMBOL
f
fr
G
f.eff
e
r
w
L
LIST OF SYMBOLS
DESCRIPTION
Frequency
Frequency resonant
Antenna Gain
Total radiated power
Total input power
Characteristics impedance
Load impedance
Input impedance
Upper frequency
Lower frequency
Center Frequency
Directivity
Substrate height
Dielectric constant
Effective dielectric constant
Antenna efficiency
Reflection coefficient
Width
Length
Reflected voltage
Incident voltage
Thickness
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p Iteration factor
D.i Patch Length Extension
Le Effective Patch Length
WP Patch Width
Lp Patch Length
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CHAPTER I
INTRODUCTION
1.1 Brief Technical Overview
The goal of this project is to design a Minkowski fractal patch antenna for Wi-Fi
application. The antenna will have properties that benefit the modern wireless
communication.
A new development of fractal antenna engineering research is driven due to
significant improvement of speed in computing, which is required for the design.
Several attributes of fractal antenna deemed as advantages over conservative antenna
types include how it radiate electromagnetic energy. This can be used to improve the
functionality of latest wireless communication receivers.
1.1.1 Wi-Fi Introduction
"Wi-Fi" is a type of wireless networking protocol that allows devices to
communicate without cords or cables. Wi-Fi is technically an industry term that
represents a type of wireless local area network (LAN) protocol based on the 802.11
IEEE network standard (Chen, 2009). It is the most popular means of communicating
data wirelessly, within a fixed location, today.
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The IEEE established 802.11 b in 1999 is to improve the data rate of the original
802.11 standard. IEEE 802.11 b wireless Ethernet also operates on the 2.4GHz band
(Chou, 2010). There are many good reasons to use IEEE 802.11 b wireless Ethernet.
One of which is due to reduced cost in fabrication because of the FR 4 and
exceptional signal range. ln order to satisfy the demand for precision and reliability,
a high performance Wi-Fi antenna must be able to operate at 2.45GHz frequency.
1.2 Objectives
a) To design a miniaturized antenna using Minkowski fractal.
b) To investigate the behavior of the Minkowski fractal patch antenna properties.
c) To make a comparison between the hardware measurement and simulation.
1.3 Problem Statements
1.3.1 Introduction
Common designs are sensitive to only a narrow range of frequencies and thus, cause
it to be less efficient. One of the ways to improve antenna performance is to use array
antenna but this technique requires larger antenna size and increased weight. Fractal
antenna designs can overcome some of these problems. Another common design
problem is antenna sensitivity to the narrow range of frequencies whith creates
inefficiency. It is a known problem for small and portable antennas. Experiments
have shown that antennas built with only a small number of iterations of a fractal
process can exhibit sensitivity at frequency.
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1.3.2 Solution Overview
Fractals can be used to enhance antenna designs. The method is in the design of
miniaturized antenna elements. These can lead to antenna elements which are more
discrete for the end user. Minkowski fractal patch antenna is proposed since it can
reduce the size with miniaturization technique· The Minkowski fractal design is
introduced into the basic structure intended to reduce the frequency of operation.
Hence, miniaturization can be achieved.
Since using fractals as an approach to antenna design is a relatively new development
in the field of antenna research, the Minkowski microstrip antenna is selected for this
project. This antenna is simple to design and its radiation properties are far better
documented in research literature than other types of antennas.
Fractals have been used in computer graphics and coding, non-linear chaotic circuits and more. Generally, by using fractals in antennas, the following properties can be achieved.
a) Reduction of physical radiator size, degree of reduction depends on type of fractal used
b) Multiband behavior is result of self-similarity
c) Radiation patterns in frequency also is self-similar
d) Non-integral ratio of following resonant frequencies
e) Opportunity of realization in planar technique
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