frequency reconfigurable archimedean spiral...
TRANSCRIPT
FREQUENCY RECONFIGURABLE ARCHIMEDEAN SPIRAL ANTENNA
MASMURNI BINTI ABDUL RAHMAN
A project report submitted in partial fulfilment of the
requirements for the award of a degree of
Master of Engineering (Electrical-Electronic and Telecommunication)
Faculty of Electrical Engineering
Universiti Teknologi Malaysia
27 JANUARY 2012
iii
Specially dedicated to my beloved mother and sisters…
Norsiah, Mastura and Siti Roselina
for their endless love that keeps me going.
iv
ACKNOWLEDGEMENT
In the name of ALLAH, thanks for His blessing to make this project successful
although the uneasiness and hardship which I have to face. Thank you for the strengths
and the spirits.
I am deeply indebted to my supervisor Assoc Prof Ir. Dr. Sharul Kamal Abdul
Rahim and also to Dr. M. Rijal Hamid for the guidance, stimulating suggestions and
encouragement during the research, from the beginning till the end of this thesis.
Thanks also to all my graduate friends who have shared ideas and discussions
during the completion of this project. Their help and ideas are much appreciated.
Last but not least, I would like to express my deepest gratitude to my mother and
sisters for their never ending support and understanding throughout my master study.
Their prays, sacrifices, and encouragements have helped and motivated me a lot
throughout the completion of this thesis.
v
ABSTRACT
The latest evolution of communication technology system has observed an
emerging of new multi-functional devices and new applications operating in different
frequencies. As the technology advances, it becomes apparent that a transceiver which
could operate at multi-frequency is in need to support the system. Hence in this thesis, a
frequency reconfigurable switchable between wideband and narrowband has been
proposed and investigated. The idea was to support a wide frequency of operation and
at the same time could be switched to operate at a single frequency in order to reduce
the interference level at the receiver. This antenna is potentially useful for UWB and
future cognitive radio systems. The proposed antenna utilized an Archimedean spiral
antenna as the wideband antenna, and it was reconfigured by adding a slot resonator to
the structure to enable narrowband operation. Two ideal switches in the form of metal
pads are used for the studies to enable the reconfiguration capability. Performance
results from the measurements and simulations results shows a good agreement in terms
of return loss and radiation pattern which shows a broad bandwidth operation at
wideband operation and 16% bandwidth for the narrowband operation with a maximum
gain of 3dBi at the frequency of operation.
vi
ABSTRAK
Evolusi terbaru sistem teknologi komunikasi dapat diperhatikan dengan
kemunculan peranti pelbagai fungsi dan juga kemunculan aplikasi baru yang beroperasi
dalam frekuensi yang berlainan. Dengan ini jelas sekali bahawa alat pemancar dan
penerima signal yang dapat berfungsi dalam pelbagai frekuensi diperlukan untuk
menyokong sistem komunikasi. Oleh itu, di dalam tesis ini, antenna yang
berkemampuan untuk mengubah frekuensi operasinya dari jalur lebar (2GHz - 8GHz)
kepada jalur sempit pada frequensi 5.8GHz telah dicadangkan dan dikaji. Antenna ini
direka supaya ianya dapat beroperasi dalam pada jalur lebar dan dalam masa yag sama
boleh ditukarkan supaya berfungsi pada jalur sempit hanya dengan menggunakan satu
antenna sahaja untuk mengurangkan tahap gangguan signal pada alat penerima.
Antenna ini berpotensi untuk digunakan untuk aplikasi radio kognitif sistem pada masa
depan. Antenna yang dicadangkan menggunakan struktur antenna lingkar Archimedean
dan ditambah dengan slot resonator untuk membolehkan ianya direkonfigurasi.
Keputusan prestasi dari simulasi dan pengukuran menunjukkan satu persamaan antara
satu sama lain dari segi kehilangan balikan dan pola radiasi yang menunjukkan respon
frekuensi jalur lebar apabila beroperasi pada jalur lebar, dan menghasilkan 16% lebar
jalur untuk operasi pada jalur sempit
vii
TABLE OF CONTENTS
CHAPTER TITLE PAGE
DECLARATION ii
DEDICATION iii
ACKNOWLEDGEMENT iv
ABSTRACT v
ABSTRAK vi
TABLE OF CONTENTS vii
LIST OF TABLES x
LIST OF FIGURES xi
LIST OF ABBREVIATIONS xiv
LIST OF SYMBOLS xvi
1 INTRODUCTION
1.1 Introduction 1
1.2 Background of Study 2
1.3 Problem Statements 3
1.4 Objectives 3
1.5 Scope of Project 4
1.6 Thesis Organization 4
viii
2 LITERATURE REVIEW
2.1 Introduction 6
2.2
Microwave Filter
2.2.1 Filter Symmetry
8
9
2.3 Review of Previously Designed Reconfigurable Antenna 10
2.3.1 Fixed Frequency Reconfigurable Antenna 10
2.3.2 Wideband-Narrowband Reconfigurable Antenna 16
2.3.3 Tunable reconfigurable antenna 19
2.4 Wideband Antenna 21
2.4.1 Archimedean Spiral Antenna (ASA) Geometry 21
2.4.2 Operating Principle 23
2.4.3 Coplanar Waveguide Feed Structure 25
2.5 Summary 26
3 METHODOLOGY
3.1 Introduction 27
3.2 Simulation 29
3.2.1 Wideband Antenna Design 29
3.2.2 Slot Resonator Model Construction 31
3.2.3 Optimization of the Slot Resonator 32
3.3 Fabrication 33
3.4 Antenna Measurements 34
3.5 Summary 34
4 RESULTS AND DISCUSSION
4.1 Introduction 35
4.2 Simulation Results 35
4.2.1 Wideband Configuration Mode 36
4.2.2 Slot Width Variation at Switch Location 37
4.2.3 Meandered Slotline Width Variation 38
ix
4.2.4 Comparison of Simulated Gain between
Wideband and Narrowband Mode
43
4.2.5 Comparison of Simulated Axial Ratio between
Wideband and Narrowband Mode
44
4.2.6 Simulated Radiation Pattern 45
4.3 Measurement Results 48
4.3.1 Comparison of Simulated and Measured Return
Loss
48
4.3.2 Comparison of Simulated and Measured
Radiation Pattern
50
4.4 Summary 52
5 CONCLUSION AND FUTURE WORKS
5.1 Conclusion 53
5.2 Future work 54
REFERENCES 55-58
x
LIST OF TABLES
TABLE NO. TITLE PAGE
3.1 Parameter length of the Archimedean Spiral antenna
31
3.2 Parameters length of the slot resonator 32
xi
LIST OF FIGURES
FIGURE NO. TITLE PAGE
2.1 Reconfigurable method using switched feed and switched
ground.
10
2.2 Rectangular monopole antenna with elliptical base. 11
2.3 Combination of PIFA and Monopole antenna 12
2.4 Reconfigurable printed dipole antenna 12
2.5 Multi-segment printed loop structure antenna 13
2.6 Rectangular microstrip patch with U-shaped slot 14
2.7 A tunable dual frequency stacked circular disc microstrip
antenna
14
2.8 Slot antenna (a) Dual band reconfigurable slot antenna ,
(b) T-slotted reconfigurable PIFA antenna
15
2.9 A Reconfigurable Space-Filling-Based Slot Antenna 16
2.10 Frequency reconfigurable half-lambda length dipole
antenna
16
2.11 Reconfigurable Vivaldi antenna structure 17
2.12 Antenna configuration in [17], (a) Front view (b) Rear
view
18
2.13 Geometry of Reconfigurable Log Periodic Antenna (a)
Front view, (b) Side view
19
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2.14 Structure of (a) reconfigurable handset chassis (b)
elements with discrete port
20
2.15 Printed slot bent antenna for fixed and tunable
reconfigurability
20
2.16 Reconfigurable U-slot microstrip antenna 21
2.17 Archimedean Spiral Antenna geometry 23
2.18 Two arms gap-fed stripline spiral antenna 25
2.19 Three arms coplanar waveguide-fed Archimedean
spiral antenna
26
2.20 Diagram of coplanar waveguide feeding configuration 27
3.1 Flowchart of the project works 29
3.2 Geometry of non-reconfigurable Archimedean spiral
antenna
31
3.3 Meandered slot line of slot resonator 32
3.4 Different shapes of slot resonator (a) L-shaped, (b)
rectangular rings, (c) circular rings and (d) circular
heads
33
3.5 Prototype of the fabricated antenna 34
4.1 Wideband configuration (a). with the presence of slot
resonator, (b). without the presence of slot resonator
37
4.2 Effect of the presence of slot resonator on simulated
return loss
38
4.3 Simulated return loss with different slot width at switch
location
39
4.4 Slot resonator meandered slotline parameters 39
4.5 Simulated return loss with H1 varied 40
4.6 Simulated return loss with H2 varied 41
4.7 Simulated return loss with R1 varied 41
4.8 Simulated return loss with R2 varied 42
4.9 Simulated return loss with R3 varied 43
4.10 Comparison of simulated gain between wideband mode
and narrowband
44
4.11 Simulated axial ratio at frequency range 2GHz to 8GHz 45
xiii
4.12 Simulated axial ratio at frequency range 2 GHz to 4
GHz
46
4.13 Simulated radiation pattern at two principal planes in
wideband mode, (a) H-Plane(xz), (b) E-Plane (yz).
47
4.14 Simulated radiation pattern at two principal planes in
narrowband mode (a)H-Plane(xz) and (b) E-Plane (yz)
48
4.15 Prototype of the fabricated antenna 49
4.16 Comparison of simulated and measured return loss at
wideband mode
49
4.17
4.18
Comparison of simulation and measurements return
loss for narrowband operation
Comparison between simulated and measured
normalized radiation pattern for wideband
configuration mode (a) H-Plane (xz), (b) E-Plane (yz).
50
51
xiv
LIST OF ABBREVIATIONS
mm - Millimeter
GHz - Gigahertz
MHz - Megahertz
UWB - Ultra Wideband
ASA - Archimedean Spiral Antenna
CPW - Coplanar Waveguide
WiFi - Wireless Fidelity
WLAN - Wireless Local Area Network
WiMAX - Worldwide Interoperability for Microwave Access
WPAN - Wireless Personal Area Network
Gbps - Gigabits per second
Mbps - Megabits per second
SDR - Software Define Radio
IEEE - Institute of Electrical & Electronics Engineers
MIMO - Multiple Input Multiple Output
FM - Frequency Modulated
GPS - Geostationary Position System
FET - Field Effect Transistor
RF-MEMS - Radio Frequency – M
CST MWS - CST Microwave Studio
FR4 - Fire Retardant 4
PB - Passband
xv
LP - Low Pass
GSM - Global System for Mobile Communications
DCS - Digital Communication System
PCS - Personal Communication System
UMTS - Universal Mobile Telecommunications System
LAN - Local Area Network
PIFA - Proportional-Integral
WCC - Wireless Communication Center
H-plane - Magnetic field plane
E-plane - Electric field plane
-
xvi
LIST OF SYMBOLS
dB - Decibel
dBi - Decibel isotropic
Q - Quality Factor
- Spiral Growth Rate
- Angle
- Maximum radius of
spiral
CHAPTER 1
INTRODUCTION
1.1 Introduction
In today’s fast paced communication technology changes, new applications
are rapidly emerging. UWB system, multimode radio and future cognitive radio have
become the hot topics amongst researchers nowadays. The rapid developments of
communication system have driven the invention of wireless terminal that is capable
of operating in multimode, multiband and do handover between multiple standards
[1]. These technologies combine several applications and services that we use
nowadays including Bluetooth, WiFi, WLAN, WiMAX, UWB and many others.
Cognitive radio is one of the potential use of reconfigurable antenna
employing wideband-narrowband mode. It is a smart technology that soon predicted
would replace the current technology by enabling a single device serving for many
communication applications. Cognitive radio definition as approved by IEEE and
Software Define Radio (SDR) Forum as a system that is aware of its surrounding and
can make decision about their operating behavior upon the current situation [2].
2
1.2 Background of Study
Reconfigurable antenna has been implemented in a system whereby multiple
radiation properties are required from a single element. Reconfigurable antenna has
been applied in various applications including cellular system, Multiple Input
Multiple Output (MIMO) communication [3], cognitive radio, military applications
and plug and play reconfigurable satellites. The antenna has been incorporated in
mobile devices [4,5] in response to high demand for multiple services being
incorporated in one device such as for WiFi/WLAN connectivity, Bluetooth, FM
Radio, Global Positioning System (GPS), and pentaband cellular services. A five
band reconfigurable antenna has been developed in [6] to cover 5 cellular radio
frequency bands for global operation. It also has been applied to laptops [7] and base
station [8] whereas it has to operate at different frequencies for different services.
Reconfigurable antenna can be classified into four categories based on
previous work and is categorized based on its reconfigurable properties. The first one
is frequency reconfigurable antenna [9, 10, and 11], the second one is reconfigurable
radiation pattern antenna [12], the third one is reconfigurable polarization antenna
and the last one is any combination of the mentioned properties [13].
Many techniques have been employed in order to control the antenna
reconfiguration ability. However, fixed reconfiguration and tunable reconfiguration
are the most popular techniques used. In fixed configuration, the frequency,
polarization or beam is changed at fix value using switches like PIN diode, RF-
MEMS or Field Effect Transistor (FET). As for tunable configuration, the frequency,
polarization or beam is smoothly changed from specific range. It is implemented
using lumped elements integrated into microstrip for example, varactor diodes.
3
1.3 Problem Statement
For the multimode terminal to be realized, it needs to be able to operate in
multi frequency. However, a receiver in this system may be susceptible to
interference from other devices in range that operates in the same or neighboring
frequencies; thus the efficiency of the receiver could be compromised. In addition,
the impedance bandwidth of UWB system span from the range of 3GHz to 10.6GHz.
This wide bandwidth includes the operating frequency of WLAN and WiMAX
which may interfere with the UWB system at the receiver.
Moreover, fast growing in telecommunication market with increasing users
and services has led to the congestion in the available bandwidth. Even with today’s
existing users and application, almost all the available spectrum has already been
occupied, thus the allocation for new users and applications would pose a major
problem to the already congested spectrum. Hence, a frequency agile antenna such as
wideband antenna that can be reconfigured to operate at a specific frequency is
desirable to reduce the interference level [2].
1.4 Objectives
The objectives of this project are:
1. To design a reconfigurable Archimedean spiral antenna that can be switched
between wideband-narrowband configurations at wide bandwidth of 2GHz to
8GHz and narrow bandwidth at 5.8GHz for WiMAX applications.
4
1.5 Scopes of Project
The scopes of this project include the design of slot resonator that forms a
filter to be implemented to Archimedean spiral antenna as a wideband antenna. The
design of the antenna with a reconfigure capability is simulated with CST
Microwave Studio 2010 and is fabricated on FR4 photo resist board by chemical
etching technique. The antenna characteristics and performance such as its operating
bandwidth, gain, axial ratio and radiation pattern are justified through the simulation
results and measurements from the fabricated antenna.
1.6 Thesis Organization
This thesis is organized into five chapters:
Chapter I briefly describes the introduction of the thesis. It covers topics
such as the context, problem statement, objectives and scope of the project.
Chapter II explains the literature review of the topics related to this
research work. Three main topics have been highlighted which are types of available
reconfigurable antenna, filter theory and design structure, and Archimedean spiral
antenna.
Chapter III explains the methodology of the project. This chapter will
briefly explicate the design process of slot resonator to filter the antenna from broad
impedance bandwidth to narrow bandwidth. The fabrication and measurements
process and techniques are presented in this chapter.
5
Chapter IV presents the results obtained from the simulation. These results
are analyzed and discussed in detail. Here the results before and after implementation
of slot resonator are explained in detailed.
Chapter V presents the conclusion and recommendations or suggestions
for future work.
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