Embed Size (px)
Citation preview
1
PATTERN RECONFIGURABLE ANTENNA
ELISBETH A/P MURUGAS
This Report Is Submitted In Partial Fulfillment Of Requirement For The Bachelor
Degree Of Electronic Engineering (Wireless Communication)
Faculty of Electronic and Computer Engineering
Universiti Teknikal Malaysia Melaka
June 2015
2
UNIVERSTI TEKNIKAL MALAYSIA MELAKA
FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER
BORANG PENGESAHAN STATUS LAPORAN
PROJEK SARJANA MUDA II
Tajuk Projek : PATTERN RECONFIGURABLE ANTENNA
Sesi Pengajian
: 1 4 / 1 5
Saya ELISBETH A/P MURUGAS mengaku membenarkan Laporan Projek Sarjana Muda ini disimpan di Perpustakaan dengan syarat-syarat kegunaan seperti berikut: 1. Laporan adalah hakmilik Universiti Teknikal Malaysia Melaka.
2. Perpustakaan dibenarkan membuat salinan untuk tujuan pengajian sahaja.
3. Perpustakaan dibenarkan membuat salinan laporan ini sebagai bahan pertukaran antara institusi
pengajian tinggi.
4. Sila tandakan ( √ ) :
SULIT*
*(Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia seperti yang termaktub di dalam AKTA RAHSIA RASMI 1972)
TERHAD**
**(Mengandungi maklumat terhad yang telah ditentukan oleh organisasi/badan di mana penyelidikan dijalankan)
TIDAK TERHAD
Disahkan oleh:
__________________________ ___________________________________
(ELISBETH A/P MURUGAS) (DR. MOHAMAD ZOINOL ABIDIN ABD AZIZ)
Tarikh: ……………………….. Tarikh: ………………………..
3
“I hereby declare that this is the results of my own paper except for quotes as cited in the
references.”
Signature :
Author : ELISBETH A/P MURUGAS
Date : 30th JUNE 2015
4
“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 Degree of Electronic and
Computer Engineering (Wireless Communications) with Honors.”
Signature :
Supervisor’s Name : DR. MOHAMAD ZOINOL ABIDIN ABD AZIZ
Date : 30th JUNE 2015
5
This project and research work is dedicated to any beloved parents for their devoted
caring throughout my life, my loving brother and sister, also my friends for their
encouragement and love.
6
ACKNOWLEGDEMENT
First and foremost, I want to thanks the god because without his grace I will not
able to complete this Final Year Project (FYP) and report for the session 2015 as well as
possible. Here, I would like to thank my University Teknikal Malaysia Melaka (UTeM)
coordinator/supervisor Dr. Mohamad Zoinol Abidin Abd Aziz, who advice and guide
me to complete the Final Year Project and report in time. During to complete this Final
Year Project (FYP) and report, I face lots of problems and difficulties. However, I
manage to crossed it all with patience and complete it properly. The journey in
completing Final Year Project (FYP) and report really teach me in terms of leadership,
proper time management, communication skill, technical knowledge, soft skill and so
many more. The advice and encouragement from supervisor is really motivating me to
do the best. In addition, my family members and friends also became a part of in
completing the Final Year Project (FYP) and report, which help me in giving some
rational idea and supports. Finally, I would like to thank those involved directly and
indirectly in completing the Final Year Project (FYP) and report successfully. Thank
very much to you all.
7
ABSTRACT
The recent wireless communication systems tend to be high-capacious,
multifunctional and cover more frequency bands. Therefore, the quantity of the antenna
is becoming larger and larger. This will lead to large communication system equipment,
increased costs, and electromagnetic compatibility problems. This thesis presents the
design of a pattern reconfigurable antenna which can operable at 2.4GHz for wireless
communication system using electrical switching technique with integration of RF PIN
diodes. For this project, a rectangular microstrip patch antenna was first designed and
fabricated as a reference. Then a microstrip patch antenna with a partial ground plane
base equipped with two pin diode is designed to get pattern reconfigurability. Two PIN
diode switches are mounted over the slots in the ground plane optimize to yield the
maximum number of radiation pattern and to enhance the resonance frequency, return
loss, gain and efficiencies. This antenna is an attractive candidate for WLAN
applications. While standard antennas radiate the energy in a fixed direction, pattern
reconfigurable antenna allows a single radiation structure to behave as several antennas
with different radiation properties. Pattern reconfigurability enables wireless
communication systems to avoid noisy environments, maneuver away from electronic
jamming, and save energy by redirecting signals toward intended users only. Pattern
configurable antennas are frequently used to increase channel capacity and broaden the
coverage area of wireless system.
8
ABSTRAK
Sistem komunikasi tanpa wayar hari cenderung untuk menjadi capacious tinggi,
pelbagai fungsi dan merangkumi lebih banyak band frekuensi. Oleh itu, kuantiti antena
menjadi lebih besar dan lebih besar. Ini akan membawa kepada peralatan sistem
komunikasi yang besar, kos meningkat, dan masalah keserasian elektromagnet. Tesis ini
akan membentangkan rekabentuk antena reconfigurable corak yang boleh beroperasi
pada 2.4GHz sistem komunikasi tanpa wayar yang menggunakan teknik pensuisan
elektrik dengan integrasi diodes RF PIN. Bagi projek ini, sebuah segi empat tepat
microstrip patch antena pertama direka dan direka sebagai rujukan. Kemudian antena
patch microstrip dengan kapal terbang sebahagian tanah asas dilengkapi dengan dua pin
Diod direka untuk mendapatkan corak reconfigurability. Dua PIN Diod, suis dipasang ke
slot dalam satah bawah mengoptimumkan hasil jumlah maksima corak sinaran dan
meningkatkan kekerapan resonans, kehilangan kembali, keuntungan dan kecekapan.
Antena ini adalah untuk calon yang menarik untuk aplikasi WLAN. Manakala standard
antena memancar tenaga arah tetap, antena reconfigurable corak membolehkan sinaran
satu struktur untuk berkelakuan sebagai beberapa antena dengan sifat-sifat sinaran yang
berbeza. Corak reconfigurability membolehkan sistem komunikasi tanpa wayar untuk
mengelakkan persekitaran bising, bergerak dari jamming elektronik dan menjimatkan
tenaga dengan melencongkan isyarat ke arah pengguna sahaja. Corak dikonfigurasikan
antena sering digunakan untuk meningkatkan kapasiti saluran dan meluaskan kawasan
liputan sistem tanpa wayar.
9
CONTENTS
CHAPTER TOPIC PAGES
PROJECT TITLE i
REPORT VERIFICATION STATUS FORM ii
DECLARATION iii
SUPERVISOR DECLARATION iv
DEDICATION v
ACKNOWLEDGEMENT vi
ABSTRACT vii
ABSTRAK viii
TABLE OF CONTENT ix
I INTRODUCTION
1.1 Introduction of the Project 1
1.2 Problem Statement 3
1.3 Objectives 5
1.4 Scope 5
II LITERATURE REVIEW
2.1 Introduction 6
2.2 Antenna 7
2.3 Basic Antenna Properties 7
10
2.3.1 Impedance 7
2.3.2 Return Loss 8
2.3.3 Bandwidth 8
2.3.4 Radiation Pattern 9
2.3.5 Gain 10
2.3.6 Polarization 10
2.4 Reconfigurable antennas 11
2.4.1 Frequency Reconfigurable antenna 12
2.4.2 Polarization Reconfigurable antenna 12
2.4.3 Pattern Reconfigurable Antenna 12
2.4.4 Compound/Multi Reconfigurable Antenna 13
2.5 Reconfiguration Techniques 13
2.5.1 Antenna Designs Based on the Integration of Radio
Frequency Microelectromechanical Systems
(RF-MEMS) 15
2.5.1.1 Frequency Reconfigurable Antenna
with RF-MEMS 16
2.5.1.2 Pattern Reconfigurable Antenna with
RF-MEMS 17
2.5.1.3 Polarization Reconfigurable Antenna
with RF-MEMS 18
2.5.1.4 Biasing of RF-MEMS Switches 19
2.5.2 Antenna Designs Based on the Integration of
PIN Diodes 20
2.5.2.1 Frequency Reconfigurable Antenna with
Pin Diode 20
2.5.2.2 Polarization Reconfigurable Antenna
with Pin Diode 23
11
2.5.2.3 Radiation Pattern Reconfigurable Antenna
with Pin Diode 24
2.5.2.4 Pattern and Polarization Reconfigurable
Antenna with PIN Diode 24
2.5.2.5 Biasing of PIN Diode Switches 25
2.5.3 Antenna Designs Based on the Integration of
Varactors 26
2.5.3.1 Frequency Reconfigurable Antenna with
Varactors 26
2.5.3.2 Biasing of the Varactor Switches 27
2.5.4 Antenna Designs Based on the Integration of
Photoconductive Switches 28
2.6 Application of Microstrip Antenna 30
2.7 Substrate Board Selection 30
2.8 Conclusions 32
III PROJECT METHODOLOGY
3.1 Introduction 34
3.2 Antenna Design 36
3.2.1 Design Specifications 37
3.2.2 Microstrip Patch Antenna (Design A) 37
3.2.3 Pattern Reconfigurable Antenna (Design B) 42
3.3 Simulation 43
3.4 Fabrication 44
3.5 Measurement 45
3.6 Summary 47
12
IV RESULT AND DISCUSSION
4.1 Introduction 48
4.2 Microstrip Patch Antenna Design (Design A) 49
4.3 Microstrip Patch Pattern Reconfigurable Antenna
(Design B) 51
4.4 Comparison between Design A and Design B 57
4.5 Conclusion 59
V CONCLUSION AND RECOMMENDATION
5.1 Conclusion 60
5.2 Recommendation and Future Work 62
REFERENCES 63
13
LIST OF FIGURES
NO TOPIC PAGES
2.1 Various Techniques Adopted to Achieve 9
Reconfigurable Antennas
2.2 Schematic Layout of the RF MEMS Integrated Frequency
Reconfigurable Quasi-Yagi Folded Dipole Antenna 10
2.3 Reconfigurable Slot-Array Antenna with RF-MEMS 11
2.4 Slot with RF-MEMS Switch 14
2.5 Operation of the RSPMA 15
2.6 Fabricated FRSPMA 18
2.7 Prototype of Polarization Reconfigurable Antenna 19
2.8 Prototype of Multidirectional Pattern Reconfigurable Antenna 21
2.9 Schematic of the Reconfigurable Circular Patch Antenna For
Pattern and Polarization Antenna 22
2.10 Schematic of Dual-Band Bent Slot Antenna with Two Varactors 23
2.11 Topology of the Reconfigurable Dual-Band Slot Antenna Using
Varactors 24
2.12 Optically Shorted Stub-Loaded Frequency-Switching Patch
Antenna 25
2.13 Frequency Response for the Antenna 27
2.14 Radiation Pattern and 3dB Beamwidth 28
2.15 Commonly Types of Polarization 29
3.1 Flowchart for Microstrip Patch Antenna 35
14
3.2 Conventional Microstrip Patch Antenna 37
3.3 Dimension of Antenna Design 39
3.4 Geometrical Structure of Conventional Microstrip Patch
Antenna 41
3.5 Modified ground with PIN diode 43
3.6 Geometrical Structure of Pattern Reconfigurable Antenna 44
3.7 Fabricated Conventional Microstrip Patch Antenna And
Pattern Reconfigurable Antenna 45
3.8 Network Spectrum Analyzer 46
3.9 Anechoic Chamber 46
4.1 Simulated and Measured Return Loss Results for Design A 49
4.2(a) Simulated Radiation Pattern on Plane-E for Design A 50
4.2(b) Measured Radiation Pattern on Plane-H for Design A 50
4.3 Measured and Simulated Return loss results for Design B 51
4.4(a) Simulated and Measured Return loss for Design B on OFF_OFF
Mode 52
4.4(b) Simulated and Measured Return Loss for Design B on ON_OFF
Mode 52
4.4(c) Simulated and Measured Return Loss for Design B on OFF_ON
Mode 52
4.4(d) Simulated and Measured Return Loss for Design B on ON_ON
Mode 53
4.5(a) Simulated Radiation Pattern on Plane-E for Design B 54
4.5(b) Simulated Radiation Pattern on Plane-H for Design B 54
4.6(a) Comparison between Simulated and Measured Radiation Patterns
on Plane-E for Design A and Design B 58
4.6(b) Comparison between Simulated and Measured Radiation Patterns
on Plane-H for Design A and Design B 58
15
LIST OF TABLES
NO TOPIC PAGES
2.1 Different Type Of Switches Used In The Design Of Electrically
And Optically Reconfigurable Antennas 15
2.2 Applications of Microstrip Antennas 30
2.3 Common Substrate Materials for Microstrip Antenna 31
2.4 Electrical Properties for Electrically and Optically Switching 33
3.1 Design Specification for Dual Band Antenna 36
3.2 Dimension of Designed Antenna 40
4.1 Surface Current for Design A 51
4.2 Total Efficiency and Directivity for Design 53
4.3 Measured and Simulated Gain for Design B 53
4.4 Surface Current for Design B 56
4.5 Comparison between Resonance Frequency, Return Loss, Gain, Radiation Efficiency and Directivity for Design A and Design B 57
16
CHAPTER 1
INTRODUCTION
1.1 Introduction to the Project
Electrical transmission of speech communication, music, pictures and other
information by using the electrical signal. Speech and music sent directly from their
sources to listeners across the close proximity through sound or acoustic waves. A photo
of the same sent directly with optical or light waves over a short distance.
At longer distances, communication wire and radio communication used to send
signals. It is a unusual circuit component, known as the ' antenna ' that has prepared
radio communications may in practice. Creating an antenna burly enough
electromagnetic field at huge distances and, mutual, it is extremely susceptible to
external electromagnetic field intimidated it. However, coupling between the receiver
and transmitter antenna is consequently miniature that the signals should be amplified in
both the sending and receiving stations. It is impossible to try radio communications
without an antenna.
Wireless communications system recently tends to be high, multi-functional and
include more frequency band. Therefore, the quantity of the antenna gets larger and
17
larger. This will lead to large equipment, communication systems, increasing cost and
the problem of electromagnetic compatibility. Remodeling antenna, which offers a wide
range of functions within the radiation pattern, frequency, or polarization, can realize the
function of various dynamic antennas as it can adjust behavior to measure different
situations and context operations. Therefore, it is effectively reducing adverse effects on
the system of wireless communication brought about by the number of antennas.
Nowadays seen from most studies of the reconfigurable antenna by numerous
institutions, reconfigurable antenna according to its function is divided into frequency
reconfigurable antenna, polarization reconfigurable antenna, pattern reconfigurable
antenna and hybrid reconfigurable antenna. The implementation methods contain using
switches, changing material electromagnetic properties, loading variable reactance,
using mechanical methods, using the parasitic units, using switchable feeding networks
to improve their performances and so on [1].
The radiation pattern is one of the main characteristics of the antenna. Thus, the
antenna pattern reconstruction cannot not be important instructions on remodeling
antenna research. Antenna pattern reconstruction can be used to avoid noise sources,
increase profit and safety systems, save energy with direct signals only in the desired
direction. The pattern or the frequency of reconfigurability can be accomplished in
several ways, such as moving to pass through the switch, using loading change to
change current behavior at the antenna, or adding parasitic elements change to alter the
elements of performance driven. Reconfigure patterns have been achieved mainly by
using parasitic elements of variable length. Switching mechanism is used to change the
existing password and giving patterns of behavior that reconstituted [2].
18
1.2 Problem Statement
High capacity is very crucial in wireless as it is required for future application. It
is because; the data transferred by users are becoming larger nowadays. For example, in
the early years the data transferred consists of only text or voice only. As time goes by,
the user is demanding higher channel capacity as they wish to send voice with picture or
text with video or text, picture, and video at the same time. These data are required more
capacity to be transferred. One of the main challenges in wireless communication is to
gain high capacity in order to fulfill future application necessities. It is important in
increasing the data transferred simultaneously. The enhancement insist for capacity in a
wireless system has provoked large study intended at achieving advanced invention to
the bandwidth provided.
Besides that, the current communication devices are portable and multiplications
supported such as Bluetooth, Wi-Fi, GPS, and so much more. These applications are
used different operating frequencies in order to avoid interferences between them. The
conventional way to support this demand is by placing two or more antennas with
different resonant frequency in that device. Obviously, this method is not effective
because combining two or more antennas proving difficult because they will probably
pair with each other causing degradation signals are received or sent. Placing two
antennas in a device also bring in the space issue since it is usually designed to be a
portable device and by placing multiple antennas in the device required more spaces.
Moreover, this will lead to large communication system equipment, increased costs, and
electromagnetic compatibility problems.
Some packages may use two or three antennas for diversity reception on small
devices to increase the probability of receiving a usable signal, but usually only one of
the antennas is used for transmission. The transmission from the portable device to a
19
base station or other access point is the weakest part of the bidectional communication
link because of the power, size, and cost restrictions imposed by portability. Moreover,
the portable device is often used in unpredictable and /or harsh electromagnetic
conditions, resulting in antenna performance that is certainly less than optimal.
Reconfigurability antennas in such a situation can provide many advantages. For
example, the capability to adjust the operating frequency antennas can be used to change
the operating band, filter out annoying signals, or tune the antenna to take account of the
novel surroundings. The radiation pattern of the antenna can be altered; it can be brought
to the access point and employ fewer power for shipping, resulting in important savings
in battery power.
Reconfigurable antennas, which offer diverse functions in radiation pattern,
frequency, or polarization, can realize the function of the multiple antennas since it can
dynamically adapt its behavior to different measurements situations and operational
contexts. Therefore, it effectively reduces the adverse effects on the wireless
communication system brought by the antenna number.
Reconfigurable antennas and devices represent a key technology for improving
the performance of wireless communication systems. Accordingly, several design
strategies for achieving reconfigurabilty in terms of one or more antenna parameters
(i.e., operating frequency, polarization, etc.) Among these, antennas with a
reconfigurable radiation pattern are of great interest due to their positive impact on
network capacity and reliability by reducing interference problems and maximizing
signal-to-noise ratio.
A remodeling pattern of electromagnetic radiation is radiator pattern changing
with the switch. Typically, the frequency of such antenna operations is reserved
unvarying. But in a few cases it is considered to contain dissimilar radiation patterns at
20
dissimilar frequencies. Pattern reconfigurability allows wireless communication system
in order to avoid a noisy environment, moving from electronic jamming, and save
energy with the direct signal to the direction of the intended users. The antenna pattern is
often used to raise the configured capacity channels and expanded the coverage of a
wireless system.
1.3 Objective
The main purpose of this project is to design, simulate and fabricate pattern
reconfigurable antenna for wireless communication system using electrical switching
technique with integration of RF PIN diodes.
1.4 Project Scope
The project scope is focused on microstrip patch antenna designs which provide
pattern reconfigurability. Slotted ground plane and switching techniques are added to
control surface current in order to achieve pattern reconfigurabily .
1.5 Methodology
In order to achieve the objective, a number of activities have indentified, as
outline below:
i. Investigate characteristics of microstrip patch antenna by means of simulation and
numerical analysis.
21
ii. Simulate the pattern reconfigurable antenna design model using antenna simulation
software before the actual prototype built.
iii. Integrate RF Pin diode into the proposed antenna to evaluate the reconfigurable
characteristics performance.
iv. Develop a new design prototype of pattern reconfigurable antenna.
v. Antenna performance evaluation and optimization.
CHAPTER 2
22
LITERATURE REVIEW
2.1 Introduction
In recent years, wireless communication systems have shown tremendous
growth. It will enable the accommodation of higher data rates owing to the advent of
various services such as cellular, satellite communications and wireless local area
networks. Since several applications operate either at different frequency bands or
different radiation characteristics (such as pattern or polarization), the system requires
multiple characteristic for several services. In addition, in urban areas, multipath fading
phenomena may occur after multiple reflections or scatterings. As a large number of
users are included within the limited frequency bandwidth, the probability of
interference is increased. A reconfigurable antenna can solve these problems due to its
diversity functions. In addition, it saves installation space and cost [3]. Reconfigurable
antenna is able to change the antenna frequency, bandwidth, operational radiation
pattern and polarization has become a very active field of research in the past decade.
This is mainly due to their ability to provide dynamic reconciliation of changes in the
channels of communication or system requirements [4].
23
2.2 Antenna
The fields of wireless communication at present have given more emphasis to the
field of antenna design In the early years when the available radio frequencies, an
antenna with a design that is easy to use as a tool for transmitting electrical or radio
waves in the air into all directions. This is an innovative way of communication to
replace the wired technology wireless technology was first introduced by Galileo
Marconi when he successfully start the first wireless telegraph in 1895. After that, the
development of wireless technology make rapid. Antenna development plays an
important role in wireless technology as the number of growing by leaps and bounds
from the user in broadcasting, telecommunications, navigation, radar, sensor, and
perhaps for the future cognitive radio wireless communications for example [5].
2.3 Basic Antenna Properties
The basic features that are used to explain the performance of the antenna
including a fixed Voltage Impedance, Wave Ratio (VSWR), broadband, radiation
pattern, 3 dB beam width, profitability and ultimately polarization.
2.3.1 Impedance
Antenna input impedance identically must match the characteristics of the
transmission lines for maximum energy transfer archives between coaxial transmission
line and antenna. If the antenna input impedance not equal to the characteristic
impedance, transmission line will generate waves as shown at the antenna terminal and
travel back towards energy sources. This reflects the energy cause a reduction in the
24
efficiency of the system as a whole. The losses in efficiency will occur if the antenna is
being used to send or receive energy.
2.3.2 Return Loss
In telecommunications, return loss refers to the ratio of power/power
transmission delivered to the transmission lines. The value of the loss mitigation
amplitude for the Return described in comparison to energy is reversed to send energy.
Excellent antennas require a small value losses back less than point-10dB for best
performance. Lost back to Pointe-10 dB is means that only 10% of the amounts of
energy that can be seen while 90% of the amount of power delivered.
2.3.3 Bandwidth
Bandwidth is the frequency range antenna will be delivered efficiently where the
antenna meets the criteria specified a set of performance specification. When the power
antenna (3dB) ½, walk up and down this frequency has been reached and the antenna
will no longer do. Antenna operates in a wide frequency range and still maintains
satisfactory performance must have compensation circuit switched into the system to
maintain the impedance matching. The relationship between the VSWR and bandwidth
shown in Figure 2.13. Antenna bandwidth can be calculated as the equation 2.1. [6]
(2.1)
Where fu = upper frequency bandwidth
