2.2 Basic Antenna Parameter
2.2.1 Transmission Line 9
2.2.2 Cross Polarization 10
2.2.3 Reflection Coefficient 10
2.2.4 Directivity 11
2.2.5 Gain 11
2.2.6 Radiation Pattern 11
2.2.7 Bandwidth 12
2.2.8 Beamwidth 13
2.2.9 Efficiency 14
2.3 Graphene Material 15
2.4 Antenna 2.4.1 Size of Antenna
17 2.4.2 Tapered Slot
17 2.4.3 Antipodal Flares
19 2.3.4 Antenna Length
19 2.3.5 Antenna Width
20 2.3.6 Antenna Thickness
20 2.3.7 Transmission Line
20 2.3.8 Microscrip Line
22 2.3.9 Substrate Material
23 2.3.10 Antenna Port
25
III ANTIPODAL VIVALDI ANTENNA DESIGN
3.0 Introduction
27 3.1 Substrate Material
27 3.2
Design Specification 28
3.3 Antipodal Vivaldi Design
29 3.4
Antenna Length 29
3.5 Antenna Width 30
3.6 Antenna Slope Curve and Stripline Width
30 3.6
Feeding Technique 32
3.7 New Material
32 3.8 Simulation
33
IV RESULT AND DISCUSSION
4.0 Introduction 35
4.1 Initial Design 35
4.2 Parametric Study
36 4.2.1 Minor Tapered Length, D
38 4.2.2 Antenna Length
39 4.2.3 Patch Thickness, Tc
40 4.2.4 Width of wing, A
42 4.2.5 Strip line Width, G1
43 4.2.6 Conclusion
44 4.3 Optimized Design Parameter
45 4.4 Analyzed Antenna Parameter
4.4.1 Return Loss S11
46 4.4.2
Gain 47
4.4.3 Radiation Pattern
49 4.4.4
Realized Gain 51
4.4.5 Directivity
52 4.4.6
Conclusion 54
4.5 Comparison of the graphene based antenna with 55
different thickness. 4.5.1
Gain 55
4.5.2 Radiation Pattern
56 4.5.3
Realized Gain 58
4.5.4 Directivity
59 4.5.4
Conclusion 60
IV
CONCLUSION AND FUTURE WORK 5.0 Conclusion
62 5.1 Future Work
63 REFERENCES
65
LIST OF TABLES
NO TITLE
PAGE
2.1 Comparison of graphene and copper
15 3.1
Parameters of FR4 substrate 28
3.2 Design Specification of APVA
28 3.3
Graphene Material characteristics 32
4.1 Initial design Parameter of antenna
35 4.2
Fixed Parameter 36
4.3 Parameter that analyze in parameter study
37 4.4
Comparison of return loss for different minor 38
tapered length, D between graphene and copper 4.5
Comparison of return loss of antenna length,L 40
between graphene and copper 4.6
Comparison of return loss of patch thickness, Tc 41
between graphene and copper 4.7
Comparison of return loss of width of wings, A 43
between graphene and copper 4.8
Comparison of return loss of Strip line Width, G1 44
between graphene and copper 4.9
Final design of antipodal Vivaldi antenna‟s dimension 45
4.10 Comparison of results between graphene and copper
54 4.11
Radiation Pattern at E-Plane results 57
4.12 Radiation Pattern at H-Plane results
58 4.13
Summary of comparison of parameter of same 61
materials used
LIST OF FIGURES
NO TITLE
PAGE
1.1 Flowchart of the project
3
2.1 Types of antenna
6 2.2
Conventional Vivaldi antenna 7
2.3 Antipodal Vivaldi antenna
8 2.4
Balanced Antipodal Vivaldi antenna 9
2.5 Cross Polarization
10 2.6
Basic construction of Vivaldi antenna 12
2.7 Radiation characteristics of an antenna
14 2.8
Types of Taper 18
2.9 Antipodal Vivaldi TSA
19 2.10
Microstrip line 23
2.11 Electric and magnetic field lines around microscrip line 23
2.12 Electromagnetic wave in Maxwell‟s law
24 2.13
SMA connector models 26
3.1 a Front View
b Back View 29
3.2 Length of APVA
30 3.3
Width of APVA 30
3.4 APVA‟s Dimension
31 3.5
Simulation design process of APVA 33
3.6 a Front view of planar structure
34 b Back view of planar structure
34 c Bottom view of planar structure
34 4.1
Parameter that analyze in parameter study 37
4.2 Return loss in varied value of Minor Tapered Length, D
38 4.3
Return loss in varied value of antenna length, L 40
4.4 Return loss in varied value of patch thickness, Tc
41 4.5
Return loss in varied value of width of wings, A 42
4.6 Return loss in varied value of Strip line Width, G1
44 4.7
Results of S11 between graphene and copper materials. 47
4.8 Results of S11 between graphene and copper materials.
47 4.10
Gain of APVA for graphene based material 48
4.11 Gain of APVA for copper based material
48 4.12
Comparison of gain between graphene and copper 49
4.13 Radiation pattern at E-field of both APVA
49 4.14
Radiation pattern at H-field of both APVA 50
4.15 Realized Gain of APVA for graphene based material
51 4.16
Realized Gain of APVA for copper based material 52
4.17 Comparison of realized gain between graphene and copper 52
4.18 Directivity of APVA for graphene based material
53 4.19
Directivity of APVA for copper based material 53
4.20 Comparison of directivity of graphene and copper
53 4.21
Comparison of return loss of graphene‟s materials with 55 different thickness
4.22 Gain of 0.035nm graphene
56
4.23 Gain of 0.035mm graphene
56 4.24
Radiation Pattern at E-Plane 57
4.25 Radiation Pattern at H-Plane
58 4.26
Realized gain of 0.035nm graphene 59
4.27 Realized gain of 0.035mm graphene
59 4.28
Directivity of 0.035nm graphene 60
4.29 Directivity of 0.035mm graphene
60
LIST OF ABBREVIATION
Abbreviation
Description
APVA Antipodal Vivaldi Antenna
AUT Antenna Under Test
BW Bandwidth
c Velocity of Light in a vacuum
CST Computer Simulation Technology
dB Decibel
dBi Decibel per isotropic
e
c
Conduction efficiency e
d
Dielectric efficiency e
r
Radiation efficiency e
t
Total Radiation Efficiency E
Electric EIRP
Equivalent Isotropic Radiated Power FCC
Federal Communications Commission FNBW
First Null Beamwidth FR4
Flame retardant 4 GHz
Gigahertz H
Magnetic HPBW
Half Power Beam Width THz
Terahertz UWB
Ultra- WideBand
CHAPTER I:
PROJECT INTRODUCTION 1.0 Introduction
In developing of communication system nowadays, ultra-wideband UWB antennas are widely designed and developed for medical and military purposed. The
antennas usually being proposed in radar application for detect the images in greater accuracy and more efficient. Referring to the Federal Communications Commission
FCC standards, an antenna is known as UWB antenna as it is reaching the range of spectrum from 3.1- 10.6 GHz
[1][8][15][24]
. Therefore, such antenna must be compact in size as well as less weight for portability at both transmitter and receiver
[2]
.
The Antipodal Vivaldi Antenna APVA is having the suitable features suit the characteristics of the UWB design characteristics as it is classified as Tapered Slot
Antenna TSA. It is explained as an endfire travelling wave antenna which exhibits a wide beam width and moderately high directivity
[3]
. Besides that, antipodal
Vivaldi antenna has some other advantages such as low lobe level, high gain and adjustable beam width. The stripline tapered notch is the first TSA presented in the
industry. 1.1 Problem Statement
Antenna is an integral component of a radio communications system. An antenna
connected to a transmitter is the device that releases RF energy in the form of an electromagnetic field to be sent to a distant receiver
[3]
. Therefore, an improvement
on the parameter of antenna required to obtain the optimized value of the reflection coefficient, gain, beamwidth, realized gain and directivity are required. However, the
improvements in the parameter leads to manufacturing complexity by the used of dielectric rod in order to increase gain and increase the substrate layer for directivity
which will also leads to the increments of cost of the production of an antenna.
In the other hand, the capabilities of APVA antenna that built from copper are required to be improving by using graphene. Graphene is a material which has the
ability of a better conductivity compared to copper. With such characteristic, the process of data transfer could be upgrade up to terahertz THz
[2] [4] [24]
.
1.2 Objective:
Kategori