ULTRA WIDE BAND ANTENNA WITH ELECTROMAGNETIC BAND GAP STRUCTURE
Wan Khairul Anwar Bin Wan Md Marzuki
TK
7871.67 U45
W244 2010
1
Bachelor of Engineering with Honours
(Electronics and Telecommunications Engineering)
2010
UNIVERSITI MALAYSIA SARAWAK
R13a
BORANG PENGESAHAN STATUS TESIS
Judul: ULTRA WIDE BAND ANTENNA WITH ELECTROMAGNETIC BAND GAP STRUCTURE
SESI PENGAJIAN: 2009/2010
Saya WAN KHAIRUL ANWAR BIN WAN MD MARZUKI (HURUF BESAR)
mengaku membenarkan tesis * ini disimpan di Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak dengan syarat-syarat kegunaan seperti berikut:
I. Tesis adalah hakmilik Universiti Malaysia Sarawak.
2. Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak dibenarkan membuat salinan untuk Tujuan pengajian sahaja.
3. Membuat pendigitan untuk membangunkan Pangkalan Data Kandungan Tempatan.
4. Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak dibenarkan membuat salinan tesis ini sebagai bahan pertukaran antara institusi pengajian tinggi.
5. ** Sila tandakan (0) di kotak yang berkenaan
F-I SULIT (Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia seperti yang termaktub di dalam AKTA RAHSIA RASMI 1972).
r--j TERHAD (Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasi/
badan di mana penyelidikan dijalankan).
M TIDAK TERHAD
Alamat tetap: NO. 8, JALAN MAWAR 2/5,
PERSIARAN AMANJAYA 4,
(I ANDA I ANUAN FtNULIS)- (IANL)A-rANU
Disah
IA
e NY 6LiA7
DR. THELAHA BIN HJ. MASRI
BANDAR AMANJAYA, 08000 SUNGAI PETANI.
Tarikh:
IDL I/6/Q-<3 ICU
Tarikh:lama ensyara
Z/ TtUn 2o10
CATATAN * Tesis dimaksudkan sebagai tesis bagi Ijazah Doktor Falsafah, Sarjana'dan Sarjana Muda.
** Jika tesis ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/organisasi berkenaan dengan menyatakan sekali sebab dan tempoh tesis ini perlu dikelaskan sebagai
SULIT dan TERHAD.
This Final Year Project attached here:
Title: ULTRA WIDE BAND ANTENNA WITH ELECTROMAGNETIC
BAND GAP STRUCTURE
Student Name: WAN KHAIRUL ANWAR BIN WAN MD MARZUKI
Matric No: 17519
has been read and approved by:
Zý 'Tu A! -201o
Dr. The1 in Iýj. Masri Date
(S pervisor)
ULTRA WIDE BAND ANTENNA WITH ELECTROMAGNETIC BAND GAP STUCTURE
WAN KHAIRUL ANWAR BIN WAN MD MARZUKI
This project is submitted to
Faculty of Engineering, Universiti Malaysia Sarawak in partial fulfilment of the requirements
for the degree of Bachelor of Engineering
with Honours (Electronics and Telecommunication Engineering) 2010
Faculty of Engineering
UNIVERSITI MALAYSIA SARAWAK
2009/2010
DEDICATION
Dedicated to my beloved parents..
ii
ACKNOWLEDGMENT
In the name of Allah, Most Gracious and Most Merciful
My deep appreciation and heartfelt gratitude goes to my supervisor, Dr Thelaha Bin Hj Masri for his continuous guidance, supports and encouragements.
Without his patient, valuable suggestions and comments, I would not be working on this exciting research work.
I am also grateful to my friends for their advices, guidance and motivation they offered. Gratitude is also extended to faculty of engineering of Universiti Malaysia Sarawak for the full support in this project.
Finally, I thank my family whom, in many ways, has been involved in the inspiration and learning process leading to this thesis. Special appreciations to my beloved father, my loving mother, my dearly sisters and brothers, and someone special in my heart that was always there for me, in appreciation of their patience, sacrifice, support and encouragement.
Thank you all for your kindness and generosity. May Allah bless everyone.
111
ABSTRAK
Kemajuan deras dalam bidang komunikasi tanpa wayar telah mewujudkan permintaan untuk kadar pertukaran data yang tinggi, dan juga jalur frekuensi yang lebar sebagai tambahan kepada frekuensi yang sedia ada. Sistem yang beroperasi dalam julat Jalur Sangat lebar UWB, mendapat minat kerana ia dapat memberi kadar pertukaran data yang tinggi di atas jalur yang lebar. Antara isu tentang penggunaan jalur UWB adalah rekabentuk antenna. Penyelidikan dalam bidang electromagnetic selar jalur atau lebih dikenali sebagai struktur EBG telah menjadi satu bidang yang cukup menarik dan mendapat perhatian dalam komuniti antena. Struktur ini memiliki sifat yang unik iaitu keupayaannya untuk menekan perambatan golombang permukaan untuk frekuensi kendalian tertentu yang dipengaruhi oleh struktur EBG itu sendiri. Dalam projek ini, antena UWB telah menggunakan struktur EBG untuk membaiki prestasi antena terutamanya untuk meningkatkan gandaan antena dan juga membaiki corak pemancaran antenna dan juga digunakan sebagai penolakan jalur yang mana berkupayaan untuk menolak pada jalur frekuensi yang tertentu. Projek ini melibatkan teknik mengikisan cahaya manakalan substrat yang digunakan ialah FR4 yang mempunyai kebertelusan relatif 4.4 dan kehilangan tangen 0.019. Untuk projek selanjutnya, adalah disyorkan melakukan pembaikan pada dimensi talian penghantaran. Selain itu, tambahan slot pada ground juga di cadangkan untuk meningkatkan lagi parameter kehilangan balikan.
iv
ABSTRACT
Rapid changes in the field of wireless communications has to an increasing demand of higher data transfer rate and even higher bandwidths to supplement existing operating frequencies. Systems operating in the Ultra Wide Band (UWB) spectrum of frequencies create interest to many reserchers due to the fact that it can accommodate higher data transfer rate on a large bandwidth. One of the issues faced in the use of this band is the antenna design issue. The properties of UWB antennas such as bandwidth, return loss and radiation pattern will be investigated and compared between simulation and measurements. The research in the field of electromagnetic band gap or well known as EBG structure has becoming attractive in antenna community. This structure has a unique property such as the ability to suppress the propagation of surface wave in specific operating frequency defined by the EBG structure itself. In this project, UWB antenna has been add EBG structure to improve the performance of the antenna especially to improves the gain and radiation pattern and also to be as band stop filter which has capability to filter a specific targeted band of frequency. The simulation is done by using Computer Simulation Technology (CST). The fabrication process involves the photo etching technique while the substrate used for antenna fabrication is FR4 board which has relative permittivity 4.4 and tangent loss 0.019. For further work, it is recommended that work be done to improve on the dimensions of the transmission line. Besides that, addition of slot in the ground plane is also recommended to further improve the return loss parameters.
V
TABLE OF CONTENTS
Dedication
Acknowledgement Abstrak
Abstract
List of Figures List of Tables List of Symbols
List of Abbreviation
Chapter 1 INTRODUCTION
1.1 Introduction
1.2 Problem Statement 1.3 Objective
1.4 Scope of Project
Chapter 2 LITERATURE REVIEW 2.1 UWB Definition
2.1.1 Regulations Worldwide 2.2 Antenna Parameter
2.2.1 Return Loss 2.2.2 Bandwidth
I
Page
ii
iii
iv
V
X
X111
xiv
xv
1 I 3 3 4
5 5 8
11 11 12
V1
2.2.3 Directivity and Gain 12
2.2.4 Radiation Pattern 12
2.2.5 Polarization 13
2.3 A Brief History of UWB Antenna 13
2.4 Application of UWB Technology 21
2.4.1 Communication Systems 21
2.4.2 Radar Systems 23
2.4.3 Positioning Systems 24
2.4.4 UWB Over Wires 26
2.4.5 Conclusion 26
2.5 Introduction of Electromagnetic Band Gap 27 2.6 Principle of Electromagnetic Band Gap (EBG)
Structure 28
2.7 Compactness in EBG structure 30
2.8 Fork like EBG structure 31
2.9 Conclusion 33
Chapter 3 METHODOLOGY 34
3.1 Introduction 34
3.2 Design Methodology 35
3.3 Determine the antenna dimension 36
3.3.1 Rectangular Patch Model 36
3.3.2 Design Specification 38
3.4 Electromagnetic band gap structure design 39
3.4.1 Design specification 40
3.5 Computer Simulation 41
vii
3.5.1 Without a Ground Plane
3.5.2 With a Partial Ground Plane 3.5.3 Addition of an EBG Structure
3.5.3.1 Separation (gap) of two patch EBG as a Variable
41 42 42
42
3.6 Summary 43
Chapter 4 RESULTS AND DISCUSSIONS 44
4.1 Introduction 44
4.2 Simulation Results
4.2.1 Without a Ground Plane
4.2.2 With a Partial Ground Plane 4.2.3 Addition of an EBG structure
4.2.3.1 0.5mm separation (gap) of the EBG structure
4.2.3.2 1.0mm separation (gap) of the EBG structure
4.2.3.3 1.5mm separation (gap) of the EBG structure
4.2.3.4 2.0mm separation (gap) of the EBG structure
4.2.3.5 2.5mm separation (gap) of the EBG structure
45 45 47 48
49
51
53
54
56
Vlll
4.2.3.6 3.0mm separation (gap) of the EBG structure
4.2.3.7 3.5mm separation (gap) of the EBG structure
4.2.3.8 4.0mm separation (gap) of the EBG structure
4.2.3.9 4.5mm separation (gap) of the EBG structure
58
60
62
67
4.3 Conclusion 68
Chapter 5 CONCLUSIONS & RECOMMENDATIONS 69
5.1 Conclusions 69
5.2 Recommendation for Future Research 70
REFERENCES 71
APPENDIX A 74
ix
LIST OF FIGURES
Figure Page
2.1 UWB communications spread transmitting energy across a wide spectrum of frequency
2.2 Proposed spectral mask of ECC 2.3 Proposed spectral mask in Asia 2.4a Biconical Antenna 13
2.4b Spiral Antenna 14 2.4c Sinuous Antenna
2.4d Bowtie Antenna
2.4e Circuit Board Antenna 2.4f Vivaldi Antenna
2.4g Fourpoint Antenna 2.5a Example of radar
2.5b Example of Global Positioning System 2.5c Example of CATV
2.6 2D EBG structure
2.7 A rectangular patch surrounded by EBG structure 2.8 Configuration of fork-like EBG structure
2.9 The S21 result for fork-like EBG structure 3.1 Flow Chart of Design Methodology
3.2 Structure of Patch antenna 3.3 Structure of EBG
4.1 Patch antenna without ground plane
7 9 10 15
16 17 18 18 19 19 24 25 26 29 30 31 32 35 39 41
45
X
4.2 S11 parameters for no ground lane 45 4.3 5.8 GHz radiation pattern without ground plane 46
4.4 Patch antenna with partial ground plane 47
4.5 SII parameters for partial ground plane 47
4.6 5.8 GHz radiation pattern with partial ground plane 48 4.7 Separation (gap) of the EBG structure at 0.5mm 49 4.8 S 11 parameter separation (gap) of the EBG structure at 0.5mm 49 4.9 5.8 GHz radiation pattern for separation (gap) of the EBG
structure at 0.5mm 50
4.10 Separation (gap) of the EBG structure at 1.0mm 51 4.11 SII parameter separation (gap) of the EBG structure at 1.0mm 51 4.12 5.8 GHz radiation pattern for separation (gap) of the EBG
structure at 1.0mm 52
4.13 Separation (gap) of the EBG structure at 1.5mm 53 4.14 S> > parameter separation (gap) of the EBG structure at 1.5mm 53 4.15 5.8 GHz radiation pattern for separation (gap) of the EBG
structure at 1.5mm 54
4.16 Separation (gap) of the EBG structure at 2.0mm 55 4.17 SIi parameter separation (gap) of the EBG structure at 2.0mm 55 4.18 5.8 GHz radiation pattern for separation (gap) of the EBG
structure at 2.0mm 56
4.19 Separation (gap) of the EBG structure at 2.5mm 57 4.20 SII parameter separation (gap) of the EBG structure at 2.5mm 57 4.21 5.8 GHz radiation pattern for separation (gap) of the EBG
structure at 2.5mm 58
4.22 Separation (gap) of the EBG structure at 3.0mm 59 4.23 Sii parameter separation (gap) of the EBG structure at 3.0mm 59
RI
4.24 5.8 GHz radiation pattern for separation (gap) of the EBG
structure at 3.0mm 60
4.25 Separation (gap) of the EBG structure at 3.5mm 61 4.26 SI i parameter separation (gap) of the EBG structure at 3.5mm 61 4.27 5.8 GHz radiation pattern for separation (gap) of the EBG
structure at 3.5mm 62
4.28 Separation (gap) of the EBG structure at 4.0mm 63 4.29 SI I parameter separation (gap) of the EBG structure at 4.0mm 63 4.30 5.8 GHz radiation pattern for separation (gap) of the EBG
structure at 4.0mm 64
4.31 Separation (gap) of the EBG structure at 4.5mm 65 4.32 SII parameter separation (gap) of the EBG structure at 4.5mm 65 4.33 5.8 GHz radiation pattern for separation (gap) of the EBG s
tructure at 4.5mm 66
4.34 Comparison of S1 i parameters for different separation gap of EBG
Structure 67
4.35 Sii parameters for the best separation gap of EBG structure 67
xii
LIST OF TABLES
Table Page
2.1 UWB limits for the America, Europe and Japan 2.2 UWB limits for the Singapore UFZ
3.1 The antenna parameters summaries
8 11
38
X111
LIST OF SYMBOLS
dB - Decibel
W- Width of rectangular patch antenna L- Length of rectangular patch antenna Cr - Dielectric constant
h- Substrate height
1- transmission line length E Electric Field
H Magnetic Field
Permittivity
µ Permeability
x Wavelength
ß Propagation Constant
v Conductivity of Metal
rl Normalized wave impedence I' Reflection Coefficient
fH High frequency
fL Low frequency
fc Centre frequency
MHz Megahertz
GHz Gigahertz
S11 Return loss
S21 Transmission coefficient
xiv
LIST OF ABBREVIATION
UWB - Ultra Wide Band
EBG - Electromagnetic Band Gap
FWA - Fix Wireless Access
HIPERLAN - High Performance Local Area Network
WLAN - Wireless Local Area Network
WMO - Microwave Office Software
xv
CHAPTER 1
INTRODUCTION
1.1 Introduction
Nowadays, Ultra wide band (UWB) transmission has attracted special significant attention in both industry and academia for applications in wireless communication [1]. The Federal Communication Commission (FCC) in the USA has allocated a frequency band from 3.1 GHz to 10.6 GHz for UWB transmission [2].
The FCC also regulated the spectral shape and maximum power spectral density (- 41.3 dBm/MHz) of the UWB radiation in order to limit the interference with other
communication systems. Due to their capabilities for high data rate information transmission (IEEE 802.15.3a), Ultra- Wideband communication systems are highly promising. UWB is defined as a signal either a fractional bandwidth of 20% of the center frequency or 500 MHz (when the center frequency is above 6 GHz) [2].
What makes UWB systems unique is their large instantaneous bandwidth. It
can achieve huge capacity as high as hundreds of MBps or even several GBps with
distances of 1 to 10 meters [3]. Unfortunately UWB service however overlaps with
wireless LAN, IEEE802.11 a band (5.15 GHz-5.825 GHz) and could cause severe
interference [4]. To solve this problem, UWB antenna with good notched filtering
characteristic should be implemented. There many ways to filter that specific band
and one of the latest techniques of band stop filter is by adding Electromagnetic Band Gap (EBG) structure. EBG structure has the ability to be used as band rejection in UWB antenna The performance of the antenna can be improved especially the gain and radiation pattern when EBG structure was used as a part of the antenna [5].
The application of EBG structure in antenna design also has attracted special attention. Two technologies have been considered for EBG materials. They have mainly been used to obtain microstrip antennas on thick, high-dielectric constant substrate with optimum performance. The first approach is based on using artificial substrates made of periodic metalo-dielectric resonant implants in order to have a complete forbidden band gap around the desired antenna operative frequency The second is based on micromachining or perforating the substrate interior or exterior to a patch antenna in order to lower the effective dielectric constant of the substrate.
Power losses are reduced due to surface wave excitation and also it would enhance the coupling of radiated power to space waves. [5]
Currently, the trend in telecommunication systems demand antennas with a small size or even tiny as possible. This has initiated antenna research in various directions in order to reduce the size of the antenna especially for UWB antenna.
Many antenna parameters need to be consider in designing UWB antenna This is due the fact that, either the operation bandwidth or the antenna efficiency (gain) will be decreased and also will increase the complexity [6]
2
1.2 Problem statements
UWB antenna has an ultra wide frequency bandwidth which is operating in the frequency range between 3.1 GHz and 10.6 GHz. However, the main drawback of UWB antenna is that it also overlaps with existing communication systems such as Fix Wireless Access (FWA), High performance local area network (HIPERLAN)
and wireless local area network (WLAN). To avoid the interference between the existing communication systems, a band-notch filter in UWB systems is necessary.
However, the use of a filter will increase the complexity of the UWB designs [7]. For that, this project will introduce an EBG structure to be as band-notch filter to reject at 5.8 GHz respectively.
Another one of the big issue in UWB antenna design is already become a trend where to reduce size of the antenna in order of application for portable devices, because the size affects the gain and bandwidth greatly. Therefore, to optimize the antennas capable of providing ultra wide bandwidth for impedance matching and acceptable gain will be difficult task.
1.3 Objective
" The objective of this project is to design and simulate an UWB antenna capable of operating from 3.1 GHz to 10.6 GHz frequencies of operation. To design band stop filter using EBG structure which has capability to filter a specific targeted band of frequency
3
1.4 Scope of Project
The research scope is focused on UWB antennas designs to meet the satisfied performance that can be used in UWB system and has capability to filter out the frequency of 5.8GHz to avoid the interference occur between UWB system and existing communication application. In order to achieve the objective, a number of activities have been identified, as outline below:
i. Study the concept of planar and patch antenna base on the previous research.
ii. Investigate the electromagnetic band gap (EBG) structure design method and characteristic
iii. Design and simulate the antenna based on previous similar works in published journals using CAD tools
iv. Compare the simulated results for validation purpose v. Compile results and write reports
4
CHAPTER 2
LITERATURE REVIEW
2.1 UWB Definition
On February 14,2002, a UWB frequency allocation has been made by the U. S FCC in the range from 1.99 GHz - 10.6 GHz, 3.1 GHz - 10.6 GHz, or below 960 MHz depending on the particular application [1] and work is underway by regulatory bodies to achieve the same in Europe and Asia [8]. UWB technology enables the personal area networking industry leading to new innovations and greater quality of services to the end users. UWB also has been focus as one of the most promising wireless technologies that promises to revolutionize high data rate transmission and UWB has been defined by FCC as any device with a -10 dB fractional bandwidth, greater than 20% or occupying at least 500 MHz of the spectrum [2].
Most narrowband systems occupy less than 10% of the center frequency bandwidth, and are transmitted at far greater power levels. For example, if a radio system were to use the entire UWB spectrum from 3.1-10.6 GHz, and center about almost any frequency within that band, the bandwidth used would have to be greater than 100% of the center frequency in order to span the entire UWB frequency range.
By contrast, the 802.1 lb radio system centers about 2.4 GHz with an operating
bandwidth of 80 MHz. This communication system occupies a bandwidth of only I%
of the center frequency.
In order to limit the interference with other communication systems, the FCC has been regulated the spectral shape and maximum power spectral density (-41.3 dBm/MHz) of the UWB radiation The power spectral density is the average power in the signal per unit bandwidth and hence provides important information on the distribution of power over the RF spectrum.
The fractional bandwidth is measured at -10 dB points on either side of the peak emission. If these upper and lower frequencies are represented by fH and fL, respectively, the fractional bandwidth (BW) and center frequency (fc) can be expressed as [8]:
BW = Z(fH_fL)I(fH+fL)
fc = (fH+fL)12
(2.1 a)
(2.1b)
This fractional bandwidth greatly exceeds that of other radio transmitters, which are generally confined to a narrow frequency band allocated for a specific service. As a consequence of occupying a large bandwidth, UWB devices can span a number of bands. They are able to share spectrum with existing services because of the level of emissions from UWB is very low and below the power floor of existing
6
