UWB Patch Antenna With Dual Band Notch Function.
i
UWB PATCH ANTENNA WITH DUAL BAND NOTCH
FUNCTION
KHAIRIAH NAZIRAH BINTI MOSMIN
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
ii
UWB PATCH ANTENNA WITH DUAL BAND NOTCH FUNCTION
KHAIRIAH NAZIRAH BINTI MOSMIN
This Report is Submitted in Partial Fulfillment of the Requirement for the Bachelor
Degree in Electronic Engineering (Wireless Communication) With Honours
Faculty of Electronics and Computer Engineering
University of Technical Malaysia Melaka
July 2015
iii
ABSTRAK
Beberapa tahun selepas siasatan awal pada jalur lebar ultra (UWB) sistem
tanpa wayar, usaha penyelidikan yang agak besar telah dimasukkan ke dalam reka
bentuk antena UWB dan sistem komunikasi. Antena UWB menyediakan komunikasi
jalur lebar tanpa wayar berdasarkan penggunaan denyutan sangat sempit atas
perintah nanosaat yang meliputi jalur lebar yang sangat luas dalam domain frekuensi,
dan pada jarak yang sangat pendek pada kepadatan kuasa yang sangat rendah . Pada
frekuensi yang diperuntukkan (7.5 GHz) pada sistem UWB, memang wujud
beberapa kumpulan kecil untuk standard komunikasi data lain, seperti pada frekuensi
3.69GHz untuk WiMAX (Saling Boleh Kendali Dunia bagi Akses Gelombang
Mikro), dan pada frekuensi 5.825 GHz untuk WLAN (rangkaian tanpa wayar
tempatan), yang mungkin menyebabkan gangguan elektromagnet dengan sistem
UWB itu. Dalam projek ini, antena tampalan UWB telah dicadangkan untuk
menyediakan aplikasi UWB. Jalur dwi takuk mempunyai ciri-ciri penolakan pada 3.5
GHz untuk Wi-MAX di 5.5 GHz untuk WLAN. Antena yang dinyatakan di atas
direka menggunakan Perisian Gelombang Mikro CST 2014. Antena jenis tampalan
digunakan kerana ia lebih kecil dalam dimensi dan mudah untuk difabrikasi. Antena
UWB asas dibuat. Antena ini mempunyai tampalan radiasi berbentuk penyodok dan
tampalan pembumian di belakang. Penolakkan jalur WiMax dan WLAN dapat
dicapai dengan teknik menggores dua slot bentuk C bersarang pada tampalan radiasi.
iv
ABSTRACT
A few years after the early investigation on ultra-wideband (UWB) wireless
system, considerable research efforts have been put into the design of UWB antennas
and systems for communications. These UWB antennas are providing wireless
wideband communications based on the use of very narrow pulses on the order of
nanoseconds, covering a very wide bandwidth in the frequency domain, and over
very short distances at very low power densities. Over the allocated bandwidth (7.5
GHz) of the UWB system, there exists some narrow bands for other data
communication standards, such as at frequency 3.69 GHz for WiMAX (World
Interoperability for Microwave Access), and at frequency 5.825 GHz for WLAN
(Wireless Local Area Network), which may be cause electromagnetic interference
with the UWB system. In this project, a UWB patch antenna is proposed for
providing UWB application. The dual band-notched function has rejection
characteristics at 3.5 GHz for Wi-MAX at 5.5 GHz for WLAN. The aforementioned
antenna is designed using CST Microwave 2014 software. A patch antenna is used
because it is smaller in dimension and ease of fabrication and conformity. The basic
UWB antenna is taken. The antenna has the shovel shape radiating patch and
grounding patch at the back. By etching two nested C-shaped slots in the radiating
patch band rejection is achieved for Wi-MAX and WLAN.
v
“I hereby declare that this report is the result of my own work except for quotes as
cited in the reference”
Signature
Author
: …………………………………………….
: KHAIRIAH NAZIRAH BINTI MOSMIN
vi
“I hereby declare that I have read this report and in my opinion this report is
sufficient in terms of the scope and quality for the award of Bachelor of Electronic
Engineering (Wireless Communications) With Honours”
Signature
Supervisor‟s Name
AZIZ
Date
: ……………………………………...............
: EN. MOHAMAD ZOINOL ABIDIN BIN ABD.
: ………………………………………………
vii
For mum and dad,
I grew up, but I’ll always be your little girl.
Smile.
viii
ACKNOWLEDGEMENT
Alhamdulillah, thanks to Allah S.W.T my Final Year Project (FYP) was
completed. I hereby would like to take this opportunity to thank all persons who has
involved generously in helping me and assisting me while I was completing the Final
Year Project (FYP) which is a compulsory to all Universiti Teknikal Malaysia
Melaka (UTeM) students in order to complete our degree.
I would express my deepest gratitude and thanks to my project supervisor,
En. Mohamad Zoinol Abidin bin Abd. Aziz for his undivided giving me support
morally and physically, assistance, encouragement, guidance, tolerance, information
which proved to be invaluable as completion my Final Year Project (FYP)., I would
to appreciate the guidance given by the panels especially in my project presentation
that has improved our presentation skills by their comment and tips.
Special appreciation goes to my family who also gave words of
encouragement and enthusiasm was accompanied by prayer and hopeful for me to go
ahead. Also to my entire lovely through thick and thin friends who helped provide
ideas, whether directly or indirectly in addition to jointly face the struggle in
completing this projects that are entrusted.
ix
TABLE OF CONTENT
CHAPTER
I
II
TITLE
PAGES
PROJECT TITLE
i
DECLARATION STATUS OF REPORT FORM
ii
DECLARATION
iii
SUPERVISOR DECLARATION
iv
DEDICATION
v
ACKNOWLEDGEMENT
vi
ABSTRACT
vii
ABSTRAK
viii
TABLE OF CONTENTS
ix
LIST OF TABLES
xii
LIST OF FIGURES
xiii
LIST OF ACRONYM
xv
LIST OF APPENDIX
xvi
INTRODUCTION
1
1.1 Ultra Wideband (UWB)
1
1.2
Problem statement
2
1.3
Objective of project
4
1.4
Scope of the project
4
1.5
Methodology
4
LITERATURE REVIEW
6
x
2.1
UWB Communication
6
2.2
Antenna Parameter
7
2.3
UWB Antenna Design
9
9
2.3.2 Fractal Antenna
10
2.3.3 Micro strip Patch Antenna
11
2.4
2.3.1 Printed Slot Antenna
III
IV
Band stop filter
13
2.4.1 Band notching technique
13
2.4.2 Dual band notching technique
15
METHODOLOGY
16
3.1
Methodology of Project
17
3.2
Design specification
19
3.3
Design of UWB antenna (Design A)
19
3.4
Single band notch design (Design B1 and B2)
21
3.5
Dual band notch design (Design C)
23
3.6
Simulation process
24
3.7
Fabrication process
25
3.8
Measurement process
27
RESULT ANALYSIS AND DISCUSSION
30
4.1
30
UWB antenna (Design A)
4.1.1 Result for Design A
4.2
Single Band Notch Antenna (Design B)
4.2.1 Result for Design B
4.3
Dual Band Notch Antenna (Design C)
4.3.1 Result for Design C
31
33
35
38
39
xi
V
CONCLUSION AND FUTURE WORK
42
5.1
Conclusion
42
5.2
Future Work
43
REFERENCES
44
APPENDICES
48
xii
LIST OF TABLES
NO
TITLE
PAGE
3.1
Design specification
19
3.2
Design parameter specification
21
3.3
Design parameter specification
22
3.4
Design parameter specification
23
4.1
Antenna gain, directivity and efficiency for simulation and
33
measurement result
4.2
Comparison on Design B
38
4.3
Antenna gain, directivity and efficiency for simulation and
41
measurement result
xiii
LIST OF FIGURES
No.
Title
Page
5
1.1
The flow chart of the project.
10
2.1
Various type of fractal antenna
12
2.2
Various shapes of patch antennas
12
2.3
Microstrip feed line
12
2.4
Coaxial feed or probe feed
13
2.5
Base Antenna
14
2.6
The geometry of the single band-notch UWB antenna consists of
15
an elliptical radiator
2.7
The dual band notch antenna by biased t shaped parasitic element
15
and window slot.
3.1
Flow chart of the methodology
18
3.2
The geometry of UWB antenna
20
3.3
The Geometry of single band notched antenna
22
3.4
The Geometry of dual band notched antenna
23
3.5
Perspective view of UWB Antenna (Design A)
24
3.6
Perspective view of Dual Band Notch Antenna (Design C)
25
3.7
The flow chart of Fabrication process
26
3.8
The antenna after fabrication process. (Design C)
26
3.9
Measurement setup for return loss
27
xiv
3.10
Measurement Setup for Radiation Pattern in Anechoic Chamber.
28
3.11
Horn Antenna Setup used to Measure Gain of AUT
29
4.1
The prototype of UWB antenna, Design A.
31
4.2
Comparison Return loss simulation and measurement result for
31
Design A
4.3
Comparison simulation and measurement radiation pattern for
32
Design A
4.4
Prototype of Design B1 (C-shape slot)
34
4.5
Prototype of Design B2 (U-shape slot)
34
4.6
Comparison return loss between simulation and measurement
35
result Design B1 and Design B2
4.7
Comparison simulation and measurement radiation pattern for
36
Design B1
4.8
Comparison simulation and measurement radiation pattern for
37
Design B2
4.9
Prototype of Design C
38
4.10
Comparison return loss between simulation and measurement
39
result of Design C
4.11
Radiation pattern for dual band notch antenna
40
xv
LIST OF ACRONYMS
UWB
-
Ultra Wide Band
AUT
-
Antenna Under Testing
WiMAX
-
World Interoperability for Microwave Access
WLAN
-
Wireless Local Area Network
CST
-
Computer Simulation Technology
xvi
LIST OF APPENDIX
NO
TITLE
PAGE
A1
Surface Current of The Designed Antenna
48
A2
Surface Current for single band notch U - shape antenna
49
A3
Surface Current for single band notch C - shape antenna
50
B1
The Result of The Parametric Study For Antenna A
51
B2
The Result of The Parametric Study For Antenna B1
53
B3
The Result of The Parametric Study For Antenna B2
55
B4
The Result of The Parametric Study For Antenna C
58
xvii
CHAPTER 1
INTRODUCTION
1.1 Ultra Wideband (UWB)
Ultra Wideband (UWB) technology, due to its large bandwidth, is capable of
supporting high data rate applications. The Federal Communications Commission
(FCC) agreed in February 2002 [1] to allocate 7.5 GHz of spectrum for unlicensed
use of UWB devices for communication applications in the 3.1 GHz to 10.6 GHz
frequency band.
This technology has given rise to much interest in designing wideband antennas
with performances of the broadband impedance matching, Omni-directional radiation
pattern, constant group delay, and compact size. The benefits of UWB technology
are derived from its unique characteristics that are the reasons why it presents a more
eloquent solution to wireless broadband than other technologies. The unique
characteristics are UWB has an ultra-wide frequency bandwidth; it can achieve huge
capacity as high as hundreds of Mbps or even several Gbps with distances of 1 to 10
meters [2]. This requires a data rate which is much higher than what can be achieved
through currently existing wireless technologies. Another that, UWB system is
extremely fine time and range solution even through loss, opaque media. UWB also
has low probability of detection and interception. UWB provides high secure and
high reliable communication solutions. Due to the low energy density, the UWB
signal is noise-like, which makes unintended detection quite difficult. Furthermore,
the “noise-like" signal has a particular shape; in contrast, real noise has no shape [3].
In the other hand, UWB system has immunity from multipath.
xviii
UWB system based on impulse radio features low cost and low complexities
which arise from the essentially base-band nature of the signal transmission. UWB
does not modulate and demodulate a complex carrier waveform, so it does not
require components such as mixers, filters, amplifiers and local oscillators, thus
make UWB an inherent capability for integration in low cost, low power Integrated
Circuit (IC) processes. Instead of using a single antenna at single frequency, UWB
antenna can operate at for many applications because of the wide operating band.
UWB is the leading technology for freeing people from wires, enabling wireless
connection of multiple devices for transmission of video, audio and other high
bandwidth data. Designed for short range, WPAN, it is used to relay data from a host
device to other devices in the immediate area. Recent years, rapid developments have
been experimented on the technology using UWB signals. UWB technology offer
major enhancements in three wireless application areas: communications, radar and
positioning or ranging. UWB technology can be delivered also over wire lines and
cables such as cable television (CATV) application.
1.2
PROBLEM STATEMENT
Wireless communication is simply the act of transferring information from
one place to another without wired connection. UWB or ultra wideband is a
communication method used in wireless networking to achieve high bandwidth
connections with low power utilization. The UWB signal is a very low power signal
and therefore the power of any single UWB device can be compared to that of a
noise floor. But when a number of such devices operate simultaneously then the
interference level could rise significantly above the level of the noise floor. Over the
allocated bandwidth (7.5 GHz) of the UWB system, there exists some narrow bands
for other data communication standards, such as 3.4-3.69 GHz for WiMAX (World
Interoperability for Microwave Access), 5.15-5.825 GHz for WLAN (Wireless Local
Area Network), which may be cause electromagnetic interference with the UWB
system. Because of the existence of other wireless standards an additional
requirement for UWB antennas is to reject some multi-bands within the UWB passband. A wireless local area network (WLAN) is a wireless distribution method for
two or more devices that use high-frequency radio waves and often include an access
xix
point to the Internet. A WLAN allows users to move around the coverage area, often
a home or small office, while maintaining a network connection.
Interference is any barrier to the communication transaction and it can best be
described as the effect of unwanted signals or noise on the reception of a wanted
signal. The two most common causes of interference are radio transmitters and
electrical equipment. All communication systems that transmit signals (radio
transmitters) are capable of generating interference. These systems include e.g.
amateur radios, radio and television stations and mobile phones. Electrical
interference may be caused by power lines or electrical equipment in your home.
Interference may prevent reception altogether, may cause only a temporary loss of a
signal, or may affect the quality of the sound or picture produced by the equipment.
Due to telecommunication system, there are many types of interference.
Interference will affect the performance of the bandwidth. Such as decrease in the
wireless range between devices, decrease in data throughput over Wi-Fi and
intermittent or complete loss of the wireless connection. Interferences may be
cancelled or mitigated by changing antenna patterns as required. To avoid the
interference between the UWB, WLAN and WiMAX systems, a band-notch filter in
UWB systems is necessary. However, the use of a band stop filter will increase the
complexity of the UWB systems. Therefore, several techniques used to introduce a
notched band for rejecting the WLAN and WiMAX interference have been
investigated, which include such as inserting a half-wavelength slot structure, slitting
on the edges, utilizing fractal feeding structure, and parasitic quarter-wave patch or
parasitic open-circuit stub. With the notched band characteristic, the antenna allows
to reconfigurable its frequency that only responsive to other frequencies beyond the
rejection bands within UWB bandwidth
1.3
OBJECTIVE
The main purpose of this project is to design, fabricate and simulate the UWB
antenna with dual band notch characteristics. Which have two narrow frequency that
have stop band at 3.38 -3.82 GHz for WiMAX and stop band at 5.3 -5.8 GHz for
WLAN system.
xx
1.4
SCOPE OF WORK
The project scope is focused on patch UWB antenna designs that provide an
ultra-wideband bandwidth which is operate in 3.1GHz – 10.6GHz. The notch
techniques are added to improve bandwidth which is notched at frequency 3.38 3.82 GHz for WiMAX and notched at 5.3 -5.8 GHz for WLAN system. The
notch techniques are achieved by adding several shapes on the patch on the
antenna. Simulate and optimized the performance such as return loss, gain,
radiation pattern (S11) of the antenna to achieve stop band at desired frequency
using CST Microwave 2014 software. The fabrication of the optimized antenna is
using FR-4 substrate. The measurement of the performance is using virtual
network analyser and chamber room.
1.5
METHODOLOGY
The methodology of this project started with literature review by doing
research on journal related to design of UWB antenna, single band notch design
and design to achieve dual band notch characteristic.
The primitive UWB antenna then design which has he frequency range from
3.1GHz to 10.6 GHz. The designed antenna is designed and running simulated
for the parameters of return loss, bandwidth, total efficiency, directivity and
realized gain using CST Microwave Studio Suite 2014. Parametric study is
carried out to achieve the optimized and most wanted design.
The simulation process is kept running until the desired result is obtained
before move to fabrication process. Further design process will be discussed in
chapter 3.
The measurement process is doing after done fabrication process. The
measured result will be compare with simulated result. Analysis is completed
based upon the measured result as well as the simulated result Figure 1.1 below
shows the flow chart of this project.
xxi
UWB PATCH ANTENNA WITH DUAL BAND NOTCH
FUNCTION
KHAIRIAH NAZIRAH BINTI MOSMIN
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
ii
UWB PATCH ANTENNA WITH DUAL BAND NOTCH FUNCTION
KHAIRIAH NAZIRAH BINTI MOSMIN
This Report is Submitted in Partial Fulfillment of the Requirement for the Bachelor
Degree in Electronic Engineering (Wireless Communication) With Honours
Faculty of Electronics and Computer Engineering
University of Technical Malaysia Melaka
July 2015
iii
ABSTRAK
Beberapa tahun selepas siasatan awal pada jalur lebar ultra (UWB) sistem
tanpa wayar, usaha penyelidikan yang agak besar telah dimasukkan ke dalam reka
bentuk antena UWB dan sistem komunikasi. Antena UWB menyediakan komunikasi
jalur lebar tanpa wayar berdasarkan penggunaan denyutan sangat sempit atas
perintah nanosaat yang meliputi jalur lebar yang sangat luas dalam domain frekuensi,
dan pada jarak yang sangat pendek pada kepadatan kuasa yang sangat rendah . Pada
frekuensi yang diperuntukkan (7.5 GHz) pada sistem UWB, memang wujud
beberapa kumpulan kecil untuk standard komunikasi data lain, seperti pada frekuensi
3.69GHz untuk WiMAX (Saling Boleh Kendali Dunia bagi Akses Gelombang
Mikro), dan pada frekuensi 5.825 GHz untuk WLAN (rangkaian tanpa wayar
tempatan), yang mungkin menyebabkan gangguan elektromagnet dengan sistem
UWB itu. Dalam projek ini, antena tampalan UWB telah dicadangkan untuk
menyediakan aplikasi UWB. Jalur dwi takuk mempunyai ciri-ciri penolakan pada 3.5
GHz untuk Wi-MAX di 5.5 GHz untuk WLAN. Antena yang dinyatakan di atas
direka menggunakan Perisian Gelombang Mikro CST 2014. Antena jenis tampalan
digunakan kerana ia lebih kecil dalam dimensi dan mudah untuk difabrikasi. Antena
UWB asas dibuat. Antena ini mempunyai tampalan radiasi berbentuk penyodok dan
tampalan pembumian di belakang. Penolakkan jalur WiMax dan WLAN dapat
dicapai dengan teknik menggores dua slot bentuk C bersarang pada tampalan radiasi.
iv
ABSTRACT
A few years after the early investigation on ultra-wideband (UWB) wireless
system, considerable research efforts have been put into the design of UWB antennas
and systems for communications. These UWB antennas are providing wireless
wideband communications based on the use of very narrow pulses on the order of
nanoseconds, covering a very wide bandwidth in the frequency domain, and over
very short distances at very low power densities. Over the allocated bandwidth (7.5
GHz) of the UWB system, there exists some narrow bands for other data
communication standards, such as at frequency 3.69 GHz for WiMAX (World
Interoperability for Microwave Access), and at frequency 5.825 GHz for WLAN
(Wireless Local Area Network), which may be cause electromagnetic interference
with the UWB system. In this project, a UWB patch antenna is proposed for
providing UWB application. The dual band-notched function has rejection
characteristics at 3.5 GHz for Wi-MAX at 5.5 GHz for WLAN. The aforementioned
antenna is designed using CST Microwave 2014 software. A patch antenna is used
because it is smaller in dimension and ease of fabrication and conformity. The basic
UWB antenna is taken. The antenna has the shovel shape radiating patch and
grounding patch at the back. By etching two nested C-shaped slots in the radiating
patch band rejection is achieved for Wi-MAX and WLAN.
v
“I hereby declare that this report is the result of my own work except for quotes as
cited in the reference”
Signature
Author
: …………………………………………….
: KHAIRIAH NAZIRAH BINTI MOSMIN
vi
“I hereby declare that I have read this report and in my opinion this report is
sufficient in terms of the scope and quality for the award of Bachelor of Electronic
Engineering (Wireless Communications) With Honours”
Signature
Supervisor‟s Name
AZIZ
Date
: ……………………………………...............
: EN. MOHAMAD ZOINOL ABIDIN BIN ABD.
: ………………………………………………
vii
For mum and dad,
I grew up, but I’ll always be your little girl.
Smile.
viii
ACKNOWLEDGEMENT
Alhamdulillah, thanks to Allah S.W.T my Final Year Project (FYP) was
completed. I hereby would like to take this opportunity to thank all persons who has
involved generously in helping me and assisting me while I was completing the Final
Year Project (FYP) which is a compulsory to all Universiti Teknikal Malaysia
Melaka (UTeM) students in order to complete our degree.
I would express my deepest gratitude and thanks to my project supervisor,
En. Mohamad Zoinol Abidin bin Abd. Aziz for his undivided giving me support
morally and physically, assistance, encouragement, guidance, tolerance, information
which proved to be invaluable as completion my Final Year Project (FYP)., I would
to appreciate the guidance given by the panels especially in my project presentation
that has improved our presentation skills by their comment and tips.
Special appreciation goes to my family who also gave words of
encouragement and enthusiasm was accompanied by prayer and hopeful for me to go
ahead. Also to my entire lovely through thick and thin friends who helped provide
ideas, whether directly or indirectly in addition to jointly face the struggle in
completing this projects that are entrusted.
ix
TABLE OF CONTENT
CHAPTER
I
II
TITLE
PAGES
PROJECT TITLE
i
DECLARATION STATUS OF REPORT FORM
ii
DECLARATION
iii
SUPERVISOR DECLARATION
iv
DEDICATION
v
ACKNOWLEDGEMENT
vi
ABSTRACT
vii
ABSTRAK
viii
TABLE OF CONTENTS
ix
LIST OF TABLES
xii
LIST OF FIGURES
xiii
LIST OF ACRONYM
xv
LIST OF APPENDIX
xvi
INTRODUCTION
1
1.1 Ultra Wideband (UWB)
1
1.2
Problem statement
2
1.3
Objective of project
4
1.4
Scope of the project
4
1.5
Methodology
4
LITERATURE REVIEW
6
x
2.1
UWB Communication
6
2.2
Antenna Parameter
7
2.3
UWB Antenna Design
9
9
2.3.2 Fractal Antenna
10
2.3.3 Micro strip Patch Antenna
11
2.4
2.3.1 Printed Slot Antenna
III
IV
Band stop filter
13
2.4.1 Band notching technique
13
2.4.2 Dual band notching technique
15
METHODOLOGY
16
3.1
Methodology of Project
17
3.2
Design specification
19
3.3
Design of UWB antenna (Design A)
19
3.4
Single band notch design (Design B1 and B2)
21
3.5
Dual band notch design (Design C)
23
3.6
Simulation process
24
3.7
Fabrication process
25
3.8
Measurement process
27
RESULT ANALYSIS AND DISCUSSION
30
4.1
30
UWB antenna (Design A)
4.1.1 Result for Design A
4.2
Single Band Notch Antenna (Design B)
4.2.1 Result for Design B
4.3
Dual Band Notch Antenna (Design C)
4.3.1 Result for Design C
31
33
35
38
39
xi
V
CONCLUSION AND FUTURE WORK
42
5.1
Conclusion
42
5.2
Future Work
43
REFERENCES
44
APPENDICES
48
xii
LIST OF TABLES
NO
TITLE
PAGE
3.1
Design specification
19
3.2
Design parameter specification
21
3.3
Design parameter specification
22
3.4
Design parameter specification
23
4.1
Antenna gain, directivity and efficiency for simulation and
33
measurement result
4.2
Comparison on Design B
38
4.3
Antenna gain, directivity and efficiency for simulation and
41
measurement result
xiii
LIST OF FIGURES
No.
Title
Page
5
1.1
The flow chart of the project.
10
2.1
Various type of fractal antenna
12
2.2
Various shapes of patch antennas
12
2.3
Microstrip feed line
12
2.4
Coaxial feed or probe feed
13
2.5
Base Antenna
14
2.6
The geometry of the single band-notch UWB antenna consists of
15
an elliptical radiator
2.7
The dual band notch antenna by biased t shaped parasitic element
15
and window slot.
3.1
Flow chart of the methodology
18
3.2
The geometry of UWB antenna
20
3.3
The Geometry of single band notched antenna
22
3.4
The Geometry of dual band notched antenna
23
3.5
Perspective view of UWB Antenna (Design A)
24
3.6
Perspective view of Dual Band Notch Antenna (Design C)
25
3.7
The flow chart of Fabrication process
26
3.8
The antenna after fabrication process. (Design C)
26
3.9
Measurement setup for return loss
27
xiv
3.10
Measurement Setup for Radiation Pattern in Anechoic Chamber.
28
3.11
Horn Antenna Setup used to Measure Gain of AUT
29
4.1
The prototype of UWB antenna, Design A.
31
4.2
Comparison Return loss simulation and measurement result for
31
Design A
4.3
Comparison simulation and measurement radiation pattern for
32
Design A
4.4
Prototype of Design B1 (C-shape slot)
34
4.5
Prototype of Design B2 (U-shape slot)
34
4.6
Comparison return loss between simulation and measurement
35
result Design B1 and Design B2
4.7
Comparison simulation and measurement radiation pattern for
36
Design B1
4.8
Comparison simulation and measurement radiation pattern for
37
Design B2
4.9
Prototype of Design C
38
4.10
Comparison return loss between simulation and measurement
39
result of Design C
4.11
Radiation pattern for dual band notch antenna
40
xv
LIST OF ACRONYMS
UWB
-
Ultra Wide Band
AUT
-
Antenna Under Testing
WiMAX
-
World Interoperability for Microwave Access
WLAN
-
Wireless Local Area Network
CST
-
Computer Simulation Technology
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LIST OF APPENDIX
NO
TITLE
PAGE
A1
Surface Current of The Designed Antenna
48
A2
Surface Current for single band notch U - shape antenna
49
A3
Surface Current for single band notch C - shape antenna
50
B1
The Result of The Parametric Study For Antenna A
51
B2
The Result of The Parametric Study For Antenna B1
53
B3
The Result of The Parametric Study For Antenna B2
55
B4
The Result of The Parametric Study For Antenna C
58
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CHAPTER 1
INTRODUCTION
1.1 Ultra Wideband (UWB)
Ultra Wideband (UWB) technology, due to its large bandwidth, is capable of
supporting high data rate applications. The Federal Communications Commission
(FCC) agreed in February 2002 [1] to allocate 7.5 GHz of spectrum for unlicensed
use of UWB devices for communication applications in the 3.1 GHz to 10.6 GHz
frequency band.
This technology has given rise to much interest in designing wideband antennas
with performances of the broadband impedance matching, Omni-directional radiation
pattern, constant group delay, and compact size. The benefits of UWB technology
are derived from its unique characteristics that are the reasons why it presents a more
eloquent solution to wireless broadband than other technologies. The unique
characteristics are UWB has an ultra-wide frequency bandwidth; it can achieve huge
capacity as high as hundreds of Mbps or even several Gbps with distances of 1 to 10
meters [2]. This requires a data rate which is much higher than what can be achieved
through currently existing wireless technologies. Another that, UWB system is
extremely fine time and range solution even through loss, opaque media. UWB also
has low probability of detection and interception. UWB provides high secure and
high reliable communication solutions. Due to the low energy density, the UWB
signal is noise-like, which makes unintended detection quite difficult. Furthermore,
the “noise-like" signal has a particular shape; in contrast, real noise has no shape [3].
In the other hand, UWB system has immunity from multipath.
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UWB system based on impulse radio features low cost and low complexities
which arise from the essentially base-band nature of the signal transmission. UWB
does not modulate and demodulate a complex carrier waveform, so it does not
require components such as mixers, filters, amplifiers and local oscillators, thus
make UWB an inherent capability for integration in low cost, low power Integrated
Circuit (IC) processes. Instead of using a single antenna at single frequency, UWB
antenna can operate at for many applications because of the wide operating band.
UWB is the leading technology for freeing people from wires, enabling wireless
connection of multiple devices for transmission of video, audio and other high
bandwidth data. Designed for short range, WPAN, it is used to relay data from a host
device to other devices in the immediate area. Recent years, rapid developments have
been experimented on the technology using UWB signals. UWB technology offer
major enhancements in three wireless application areas: communications, radar and
positioning or ranging. UWB technology can be delivered also over wire lines and
cables such as cable television (CATV) application.
1.2
PROBLEM STATEMENT
Wireless communication is simply the act of transferring information from
one place to another without wired connection. UWB or ultra wideband is a
communication method used in wireless networking to achieve high bandwidth
connections with low power utilization. The UWB signal is a very low power signal
and therefore the power of any single UWB device can be compared to that of a
noise floor. But when a number of such devices operate simultaneously then the
interference level could rise significantly above the level of the noise floor. Over the
allocated bandwidth (7.5 GHz) of the UWB system, there exists some narrow bands
for other data communication standards, such as 3.4-3.69 GHz for WiMAX (World
Interoperability for Microwave Access), 5.15-5.825 GHz for WLAN (Wireless Local
Area Network), which may be cause electromagnetic interference with the UWB
system. Because of the existence of other wireless standards an additional
requirement for UWB antennas is to reject some multi-bands within the UWB passband. A wireless local area network (WLAN) is a wireless distribution method for
two or more devices that use high-frequency radio waves and often include an access
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point to the Internet. A WLAN allows users to move around the coverage area, often
a home or small office, while maintaining a network connection.
Interference is any barrier to the communication transaction and it can best be
described as the effect of unwanted signals or noise on the reception of a wanted
signal. The two most common causes of interference are radio transmitters and
electrical equipment. All communication systems that transmit signals (radio
transmitters) are capable of generating interference. These systems include e.g.
amateur radios, radio and television stations and mobile phones. Electrical
interference may be caused by power lines or electrical equipment in your home.
Interference may prevent reception altogether, may cause only a temporary loss of a
signal, or may affect the quality of the sound or picture produced by the equipment.
Due to telecommunication system, there are many types of interference.
Interference will affect the performance of the bandwidth. Such as decrease in the
wireless range between devices, decrease in data throughput over Wi-Fi and
intermittent or complete loss of the wireless connection. Interferences may be
cancelled or mitigated by changing antenna patterns as required. To avoid the
interference between the UWB, WLAN and WiMAX systems, a band-notch filter in
UWB systems is necessary. However, the use of a band stop filter will increase the
complexity of the UWB systems. Therefore, several techniques used to introduce a
notched band for rejecting the WLAN and WiMAX interference have been
investigated, which include such as inserting a half-wavelength slot structure, slitting
on the edges, utilizing fractal feeding structure, and parasitic quarter-wave patch or
parasitic open-circuit stub. With the notched band characteristic, the antenna allows
to reconfigurable its frequency that only responsive to other frequencies beyond the
rejection bands within UWB bandwidth
1.3
OBJECTIVE
The main purpose of this project is to design, fabricate and simulate the UWB
antenna with dual band notch characteristics. Which have two narrow frequency that
have stop band at 3.38 -3.82 GHz for WiMAX and stop band at 5.3 -5.8 GHz for
WLAN system.
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1.4
SCOPE OF WORK
The project scope is focused on patch UWB antenna designs that provide an
ultra-wideband bandwidth which is operate in 3.1GHz – 10.6GHz. The notch
techniques are added to improve bandwidth which is notched at frequency 3.38 3.82 GHz for WiMAX and notched at 5.3 -5.8 GHz for WLAN system. The
notch techniques are achieved by adding several shapes on the patch on the
antenna. Simulate and optimized the performance such as return loss, gain,
radiation pattern (S11) of the antenna to achieve stop band at desired frequency
using CST Microwave 2014 software. The fabrication of the optimized antenna is
using FR-4 substrate. The measurement of the performance is using virtual
network analyser and chamber room.
1.5
METHODOLOGY
The methodology of this project started with literature review by doing
research on journal related to design of UWB antenna, single band notch design
and design to achieve dual band notch characteristic.
The primitive UWB antenna then design which has he frequency range from
3.1GHz to 10.6 GHz. The designed antenna is designed and running simulated
for the parameters of return loss, bandwidth, total efficiency, directivity and
realized gain using CST Microwave Studio Suite 2014. Parametric study is
carried out to achieve the optimized and most wanted design.
The simulation process is kept running until the desired result is obtained
before move to fabrication process. Further design process will be discussed in
chapter 3.
The measurement process is doing after done fabrication process. The
measured result will be compare with simulated result. Analysis is completed
based upon the measured result as well as the simulated result Figure 1.1 below
shows the flow chart of this project.
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