RANGE DEVICE APPLICATION
NUR SYAHIRAH BINTI ESHAH BUDIN SHAH
OPTIMIZATION OF MICROSTRIP-FED SLOT FOR SHORT
RANGE DEVICE APPLICATION
NUR SYAHIRAH BINTI ESHAH BUDIN SHAH
This report is submitted in partial fulfilment of the requirements
for the degree of Bachelor of Electronic Engineering with Honours
Faculty of Electronic and Computer Engineering
Universiti Teknikal Malaysia Melaka
Tajuk Projek : Optimization of Microstrip-Fed Slot Antenna for Short Range Device
Sesi Pengajian : 2017/2018
Saya NUR SYAHIRAH BINTI ESHAH BUDIN SHAH mengaku membenarkan laporan Projek Sarjana Muda ini disimpan di Perpustakaan dengan syarat-syarat kegunaan seperti berikut:
1. Laporan adalah hakmilik Universiti Teknikal Malaysia Melaka.
2. Perpustakaan dibenarkan membuat salinan untuk tujuan pengajian sahaja. 3. Perpustakaan dibenarkan membuat salinan laporan ini sebagai bahan
pertukaran antara institusi pengajian tinggi. 4. Sila tandakan (✓):
SULIT*
(Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia seperti yang termaktub di dalam AKTA RAHSIA RASMI 1972)
TERHAD* (Mengandungi maklumat terhad yang telah ditentukan oleh organisasi/badan
di mana penyelidikan dijalankan.
TIDAK TERHAD
Disahkan oleh:
(TANDATANGAN PENULIS) (COP DAN TANDATANGAN
PENYELIA)
Alamat Tetap: No, 41, Jalan Sri Laguna 1/1, Taman Laguna,81200, Johor Bahru, Johor
Tarikh : 01 Jun 2018 Tarikh : 01 Jun 2018
*CATATAN: Jika laporan ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/organisasi berkenaan dengan menyatakan sekali tempoh laporan ini perlu dikelaskan sebagai SULIT atau TERHAD.
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
FAKULTI KEJUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER
BORANG PENGESAHAN STATUS LAPORAN
DECLARATION
I declare that this report entitled “Optimization of Microstrip-Fed Slot for Short Range
Device Application” is the result of my own work except for quotes as cited in the
references.
Signature : ………
Author : ………
APPROVAL
I hereby declare that I have read this thesis and in my opinion this thesis is sufficient
in terms of scope and quality for the award of Bachelor of Electronic Engineering with
Honours.
Signature : ………
Supervisor Name : DR. NOOR AZWAN BIN SHAIRI
DEDICATION
I dedicate this thesis to my supervisor, Dr. Noor Azwan Bin Shairi and
co-supervisor, Dr. Imran Bin Mohd. Ibrahim who have guide me throughout this
project. This thesis is also dedicated to my parents who have been a great source of
ABSTRACT
The antenna used for this project is microstrip fed-slot which is made up from
FR-4 substrate with dielectric constant of FR-4.FR-4.and loss tangent of 0.025. The antenna is for
short range device (SRD) application, thus the working frequency of the antenna is
915 MHz which has been set by Malaysian Communications and Multimedia
Commission (MCMC). However, 915 MHz frequency produce a large size of antenna.
Thus, the antenna of microstrip-fed slot is optimized which is done by using Computer
Simulation Technology (CST) software and later the result of simulation and
measurement are analyzed after the antenna is fabricated. In this project, the
optimization is done by using the parametric study on the thickness of FR-4 substrate,
height of air gap, the width and length of slot and reflector towards the microstrip-fed
slot antenna’s return loss result. The outcome of this project, size of the reflector is
managed to be reduced while maintaining the return loss below -10 dB in order to
ii
ABSTRAK
Antena yang digunakan dalam projek ini ialah microstrip fed slot di hasilkan
daripada FR-4 substrat dengan 4.4 pelamar dielektrik dan 0.025 kehilangan tangen.
Antena ini adalah untuk kegunaan aplikasi peranti jarak dekat, maka frekuensi bekerja
untuk antena ini adalah 915 MHz yang telah ditetapkan oleh Suruhanjaya Komunikasi
dan Multimedia Malaysia. Namun begitu, frekuensi 915 MHz menghasilkan antena
yang bersaiz besar. Maka dengan itu, antena microstrip fed slot dioptimumkan dengan
menggunakan perisian Computer Simulation Technology (CST) dan kemudian
keputusan simulasi dan pengukuran dianalisa selepas antena difabrikasi. Di dalam
projek ini, pengoptimuman dilakukan malalui kajian parametrik terhadap ketebalan
substrat FR-4, ketinggian jarak udara, lebar dan panjang slot serta pemantul terhadap
keputusan pulangan balik antena. Di akhir projek ini, saiz pemantul berjaya
dikurangkan disamping mengekalkan -10 dB pulangan balik untuk menjaga fungsi
ACKNOWLEDGEMENTS
Writing a thesis is hard work and would be impossible without support from other
people. First of all, I want to express my greatest appreciation towards to both of my
supervisor, Dr. Noor Azwan Bin Shairi and co-supervisor, Dr. Imran Bin Ibrahim who
gave guide me throughout this project. The thesis may not complete without their
supervision and guidance.
My special appreciation to friend’s spirit and support in providing any assistance
helps in order to complete this project. I would also like to express my appreciation
towards the PhD and Master students for sharing their knowledge and helping me to
complete the project. A special thanks to Mr. Imran and Mr. Sufian for his kind gesture
in helping me especially in the laboratory system operation procedures.
Last but not least, I would like to express my appreciation to my parents and other
members of family for their emotional, financial support and providing a lovely
environment for me to complete the study.
I humbly extend my thanks to all concerned persons who co-operated with me in
iv
Table of Contents
Declaration i
Approval i
Dedication i
Abstract i
Abstrak ii
Acknowledgements iii
List of Figures viii
List of Tables x
List of Symbols and Abbreviations xi
List of Appendices xii
CHAPTER 1 INTRODUCTION 13
1.1 Project Background 13
1.2 Problem Statement 15
1.3 Objectives 15
1.4 Scope of Project 15
1.5 Thesis Outline 16
CHAPTER 2 BACKGROUND STUDY 18
2.1 Parameter of Antennas 18
2.1.2 Antenna Gain 19
2.2 Reflecting ground Plane 20
2.3 Effect of an Air Gap 21
2.4 Methods on Reducing the Size of Antenna 22
2.4.1 Artificial Neural Network (ANN) 22
2.4.2 Defected Ground Structure (DGS) 23
2.4.3 C-shaped Rings 24
2.4.4 Inductive and Capacitive Loading 25
2.4.5 Cross-Slot 25
2.5 Methods of Optimization 27
2.5.1 Gain and Bandwidth Optimization 27
2.5.1.1 Rectangular and a Fractal U-Shaped Slot 28
2.5.1.2 Genetic Algorithm 28
2.5.1.3 Parasitic Patch 29
2.5.2 Particle Swarm Optimization (PSO) 29
2.5.3 Defected Ground Structure (DGS) 29
CHAPTER 3 METHODOLOGY 31
3.1 Project Methodology 31
3.2 Literature Review 32
vi
3.3.1 The thickness of the FR-4 substrate 33
3.3.2 Air gap 34
3.3.3 The Width of Reflector 35
3.3.4 The Width of Slot 36
3.3.5 The Length of Slot 37
3.3.6 The Length of Reflector 38
3.4 Fabrication Process 42
3.4.1 UV ray Process 43
3.4.2 Etching Process 43
3.4.3 Drying Process 44
3.4.4 Measurement Process 45
CHAPTER 4 RESULTS AND DISCUSSION 47
4.1 Return Loss 47
4.2 Radiation Pattern 49
4.3 Directivity 51
4.4 Gain 51
CHAPTER 5 CONCLUSION AND FUTURE WORKS 54
5.1 Conclusion 54
5.2 Future Works 55
APPENDICES 60
APPENDIX A 60
APPENDIX B 62
APPENDIX C 64
APPENDIX D 66
viii
LIST OF FIGURES
Figure 2.1: Radiation Intensity of Major Lobe, Side Lobe and Back Lobe. 19
Figure 2.2: ANN Model 22
Figure 2.3: Top view and Three-Dimensional View of Tulip Shaped Microstrip
Antenna. 23
Figure 2.4: Figures shows the Dumbbell shaped DGS. 23
Figure 2.5: The Current Density of Patch Array Antenna with DGS at 7.5 GHz (a) top
view (b) back view 24
Figure 2.6: Equivalent Circuit of the Center-Fed Slot. 25
Figure 2.7: Circularly polarized circular microstrip antenna with surface mounted
short horn. 26
Figure 2.8: Circular Patch with Inset Fed. 30
Figure 2.9: DGS is introduced on ground plane. 30
Figure 3.10: Flow Chart of Methodology 32
Figure 3.11: Return Loss of the thickness of FR-4 substrate of 0.8 mm, 1.0 mm and
1.6 mm. 34
Figure 3.12: Return Loss of the width of air gap of 0 mm, 13.3333 mm, 23 mm,
26.6667 mm and 40 mm 35
Figure 3.13: Return Loss of reflector’s width of 90 mm, 118.4 mm, 146.8 mm and
Figure 3.14: Return Loss of slot’s width of 2 mm, 8 mm, 14 mm and 20 mm. 37
Figure 3.15: Return Loss of slot’s length of 25 mm, 63.3333 mm, 97.5 mm, 101.667
mm and 140 mm 38
Figure 3.16: Return Loss of slot’s length of 120 mm, 153.36 mm, 163.3333 mm and 175.573 mm, 180 mm, 190 mm, 197.787 mm, 200 mm, 206.667 mm, 210 mm, 220
mm and 250 mm. 39
Figure 3.17: The dimension of the microstrip fed slot antenna 42
Figure 3.18: The dimension of reflector for microstrip fed slot antenna. 42
Figure 3.19: FR-4 substrates are sit on the UV ray machine. 43
Figure 3.20: The etching station. 44
Figure 3.21: The reflector after fabricated and soldered. 45
Figure 3.22: Side view of microstep fed slot antenna with airgap of 23 mm. 45
Figure 3.23: Figures of Vector Network Analyzer (VNA). 46
Figure 3.24: Figure shows the antenna in the anechoic chamber. 46
Figure 4.25: Return Loss of Simulation and Measurement of Optimized Microstrip
Fed Slot Antenna at the frequency of 915 MHz. 48
Figure 4.26: Return Loss of Measurement at frequency 915 MHz. 48
Figure 4.27: Three-Dimensional View of Radiation Pattern (a) Front View (b) Side
View. 49
Figure 4.28: Two-Dimensional View of Radiation Pattern at 90 Phi from (a) CST (b)
Measurement. 50
Figure 4.29: Two-Dimensional View of Radiation Pattern at 0 Phi from (a) CST (b)
Measurement. 50
Figure 4.30: Directivity in CST software. 51
x
LIST OF TABLES
LIST OF SYMBOLS AND ABBREVIATIONS
For examples:
MFSA : Microstrip Fed Slot Antenna
CST : Computer Simulation Technology
VNA : Vector Network Analyzer
MCMC : Malaysian Communications and Multimedia Commission
SRD : Short Range Device
PSO : Particle Swarm Optimization
PSO : Particle Swarm Optimization
DGS : Defected Ground Structure
AR : Axial Ratio
xii
LIST OF APPENDICES
Appendix A: Result of the Thickness of FR-4 substrate of 0.8 mm in CST. 56
Appendix B: Result of the Width of Reflector of 90 mm in CST. 58
Appendix C: Result of the Width of Slot of 2 mm in CST. 60
Appendix D: Result of the Length of Slot of 97.5 mm in CST. 62
13
CHAPTER 1
INTRODUCTION
This chapter is about the introduction of thesis project which includes the project
overview, problem statement, objectives and scope of work.
1.1 Project Background
Short range device (SRD) by definition is a radio-frequency transmitter device that
is used in the telecommunication sector for the transmission of information in which
they have low capability in causing harmful interference towards the other radio
equipment. Short range devices (SRD) are the transmitter with low power which
normally limited to 25-100 mW effective radiated power (ERP) or less which depend
on the frequency bands that limits their useful range to only a few hundred meters and
14
According to Malaysian Communications and Multimedia Commission (MCMC),
SRD are designed to meet the following basic requirements which quote as follows:
“
a) The device is intended for operating in unprotected and shared frequency
bands. Its operation shall not cause interference with other authorized
radio-communication services, and be able to tolerate any interference caused by
other radio-communication services, electrical or electronic equipment.
b) The device shall not be constructed with any external or readily accessible
control which permits the adjustments of its operation in a manner that is
inconsistent with this Technical Specification.
”
For this project, the antenna that is used for the functionality of Short Range Device
(SRD) application is microstrip fed-slot. Microstrip fed slot antennas (MFSAs) are
useful in broad range of applications due to its characteristic of low profile, light
weight, low cost, ease of integration with other active components and one of those
attractive candidates in commercial applications as there a lot of extensive research
has been going on to improve the impedance bandwidth of the microstrip antenna. The
fundamental about microstrip antenna is they have a dielectric substrate on one side
and a ground plane on the other side. However, MFSAs has also their own downside
which are low gain, low efficiency, narrow bandwidth and high loss. Microstrip
antenna has different types of feeding techniques which are co-axial and microstrip
The MFSA features the off-grid communications where the communication can be
made without the base station existing. This type of communication is important when
the emergency case happened in the area that is not covered by the normal cellular
service.
1.2 Problem Statement
In [1], the antenna of microstrip-fed slot results is a high gain antenna. However,
with the frequency of 915 MHz, a large size of antenna is produced. Although it proved
with the result of high gain, the size of the antenna needs to be looked over to match
with the function as SRD that linked with the word of mobility. The antenna needs to
be optimized so that the performance of the antenna SRD would not decline as there
are some changes that are made on the antenna.
1.3 Objectives
The objectives for this project are:
1. To optimize the microstrip-fed slot antenna for short range device
application.
2. To analyze the result of the simulation and the measurement.
1.4 Scope of Project
In this project, the design of microstrip-fed slot antenna will be optimized
under the frequency of 915 MHz for short range device (SRD) application. The
optimization of the design happened in Computer Simulation Technology (CST)
software. The antenna consists of the FR-4 as a substrate and copper plate as reflector
and ground. The optimization process needs to be considered return loss that is
16
Next, after the microstrip-fed slot antenna is fabricated, the antenna is measured
with the devices such as Vector Network Analyzer (VNA) and anechoic chamber
which later the results of both measurement and simulation are being compared and
analyzed.
1.5 Thesis Outline
In Chapter 1 introduces a little bit of the project “Optimization of Microstrip Fed
Slot Antenna for Short Range Device Application”. The problem statement is the
catalyst for the project which is answered in the objective section to solve the problem.
The scope of work is a chronology of the process that needs to be done in order to
achieve the objective.
In Chapter 2 are about the literature background that has been done by reading the
journals that has a connection with the title of “Optimization of Microstrip Fed Slot
Antenna for Short Range Device (SRD) Application”. This is done in order to grasp
some idea before conducting the project on how to optimize the performance of the
antenna.
In Chapter 3 explains the methodology used to optimize the microstrip-fed slot
antenna in order to answer the objectives. The flowchart helps the process becomes
easier as it shows how the project is being carried out. The antenna undergoes
optimization in Computer Simulation Technology (CST) software and later being
measured. The measurements are done by using Vector Network Analyzer (VNA) and
In Chapter 4 shows the result of the microstrip-fed slot antenna after the antenna
has been optimized. Both results of simulation and measurement are shown and
discussion towards the results are made.
18
CHAPTER 2
BACKGROUND STUDY
This chapter is about the background study that has been done by reading some
journals that have a connection to the project title of “Optimization of Microstrip Fed
Slot Antenna for Short Range Device Application”.
2.1 Parameter of Antennas
There are few of antenna’s parameters that need to look out while designing the
antenna in order to ensure the antenna is functioning. The parameters of the antenna
are the radiation pattern, directivity, antenna efficiency and gain and polarization [2].
2.1.1 Radiation Pattern
Radiation pattern which is also known as far field is defined as mathematical
function or a graphical representation of the antenna’s radiation properties as a space
coordinates’ function. There are four types of radiation pattern’s lobe which are the
