vii
TABLE OF CONTENTS
CHAPTER
1
2
TITLE
PAGE
TITLE
i
CERTIFICATION
ii
DEDICATION
iii
ACKNOWLEDGEMENTS
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
x
LIST OF FIGURES
xi
LIST OF SYMBOLS
xiii
LIST OF ABBREVIATIONS
xiv
INTRODUCTION
1
1.1
Project Background
1
1.2
Project Objectives
2
1.3
Project Scope
2
1.4
Statement of Problem and Summary of Issues
3
LITERATURE REVIEW
4
2.1
Wireless Body Area Networks (WBAN)
4
2.2
Antenna Considerations
5
2.2.1 Basic Antenna Parameters
6
2.2.1.1 Radiation Pattern
6
2.2.1.2 Half-Power Beamwidth
7
2.2.1.3 Return Loss
8
viii
2.2.1.4 Gain
8
2.2.1.5 VSWR
9
2.2.1.6 Operating Bandwidth
9
2.2.2 Microstrip Antennas
10
2.2.2.1 Patch Radiator
11
2.2.2.2 Dielectric Substrate Material
13
2.2.3 Feed Techniques
13
2.2.3.1 Microstrip Feed Line
14
2.2.3.2 Coaxial Feed
15
2.2.3.3 Aperture Coupled Feed
15
2.2.3.4 Proximity Coupled Feed
16
2.2.4 Microstrip Antenna Polarization
17
2.2.4.1 Circular Polarization
17
2.2.5 Circular Polarized Microstrip Antenna
20
2.2.5.1 Single Feed CP Microstrip Antenna
24
2.2.5.2 Dual Feed CP Microstrip Antenna
25
2.2.5.2 Sequantial Array CP Microstrip
Antenna
2.2.6 Factors Affecting Microstrip Antenna Design
3
25
26
CP MICROSTRIP ANTENNA DESIGN
28
3.1
Design Methodology
28
3.2
Antenna Design
30
3.2.1 Patch Dimension Calculation
31
3.2.2 Quarter-Wave Transformer and 50 Ω Feedline
4
Calculations
32
3.3
Fabrication process
34
3.4
Measurement
36
RESULTS AND DISCUSSION
37
4.1
Simulation Results and Discussion
37
4.2
Measurement Results and Discussion
39
ix
5
CONCLUSION
43
4.1
Conclusion
43
4.2
Future Works Recommendation
43
REFERENCES
44
APPENDIX
47
x
LIST OF TABLES
TABLE NO.
TITLE
PAGE
2.1
Characteristics comparison for 4 different feed techniques
17
3.1
Design Specifications
30
3.2
Criteria of antenna design
30
3.3
Initial setting of the design
32
4.1
Comparison of simulation results of design antenna
37
4.2
Peak Gain of the Proposed Antenna
42
xi
LIST OF FIGURES
TABLE NO.
TITLE
PAGE
2.1
BAN architecture
5
2.2
3D radiation patterns
7
2.3
Microstrip antenna structure
10
2.4
Operations of a Microstrip Patch
11
2.5
Common patch conductor shapes
12
2.6
Microstrip Line Feed
14
2.7
Different shapes of feed line
14
2.8
Coaxial probe feed
15
2.9
Aperture-coupled feed
16
2.10
Proximity-coupled feed
16
2.11
Circular Polarization-E fields
18
2.12
Left-Hand circularly polarized (LHCP)
18
2.13
Right-Hand circularly polarized (RHCP)
19
2.14
Geometry of Single-Feed CP Microstrip Ring Antenna and
Arrays
21
2.15
Geometry of the proposed CP Microstrip Patch Antenna
22
2.16
Geometry of a stacked square microstrip antenna with
shorting post
2.17
23
Geometry of the proposed CPW-fed broadband CP square
slot antenna
23
2.18
Singly-fed CP patches
24
2.19
Dual-fed CP patches
25
2.20
CP Microstrip Antenna Array
26
3.1
Design Methodology
29
3.2
Screenshot of the Txline Calculator
32
3.3
3-D view of modeled antenna in CST
33
3.4
Initial CP Microstrip Antenna Design Layout
33
3.5
Fabrication Process
34
xii
3.6
Proposed CP Microstrip antenna design layout and its
fabricated antenna
35
3.7
Network Analyzer
36
4.1
Simulated Return loss, S11
38
4.2
Simulated VSWR
38
4.3
Measured Return loss, S11
39
4.4
Measured Return loss, S11
39
4.5
S-parameter Smith Chart
40
4.6
Measured Radiation Pattern at Phi=0°
41
4.7
Measured Radiation Pattern at Theta=90°
41
xiii
LIST OF SYMBOLS
h
-
substrate thickness
t
-
copper thickness
FH
-
High frequency
FL
-
Low frequency
λ
-
Wavelength
tan δ
-
Loss tangent
ω
-
Radian frequency
n
–
Efficiency
mm
-
milimeter
dB
-
decibel
Hz
-
hertz
L
-
length
W
-
width
Γ
-
reflection coefficient
Z0
-
characteristic impedance
λ0
-
free-space wavelength
εr
-
dielectric constant of the substrate
c
-
speed of light 3x 10-8 m/s
xiv
LIST OF ABBREVIATIONS
CPW
-
Co-planar waveguide
FCC
-
Federal Communication Commission
HPBW -
Half Power Beamwidth
RL
Return loss
-
VSWR -
Voltage standing wave ratio