Design Of Microstrip Tri-Ring Antenna.

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DESIGN OF MICROSTRIP TRI-RING ANTENNA

NUR IZZATUL SUHANA BINTI MOHD ISA

This Report Is Submitted In Partial Fulfillment of Requirements For The Award Of Bachelor Of Electronic Engineering (Electronics

Telecommunication) With Honours

Faculty of Electronic and Computer Engineering Universiti Teknikal Malaysia Melaka

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UNIVERSTI TEKNIKAL MALAYSIA MELAKA

FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER

BORANG PENGESAHAN STATUS LAPORAN

PROJEK SARJANA MUDA II

Tajuk Projek :

DESIGN OF TRI-RING ANTENNA

Sesi

Pengajian : 0 6 / 1 0

Saya :………NUR IZZATUL SUHANA BINTI MOHD ISA……….. 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:

__________________________ _______________________________

(TANDATANGAN PENULIS)

Alamat: 3757 KG AIR MELINTAS BESAR, 13300 TASEK

GELUGOR,S.P.U,P.PINANG

Tarikh:

(COP DAN TANDATANGAN PENYELIA)

Tarikh:

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―I hereby declare that I have read this report and in my opinion this report

is sufficient in terms scope and quality for the award of Bachelor of Electronic

Engineering (Electronics Telecommunication) With Honours‖

Signature : ……….

Supervisor‘s Name : Mr Mohamad Zoinol Abidin Bin Abdul Aziz

Date : ……….

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―I hereby declare that this report is the result of my own work except for quotes as

cited in the reference‖

Signature : ………

Author : Nur Izzatul Suhana Binti Mohd Isa

Date : ………

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Special dedication to my beloved family especially my late father…

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ACKNOWLEDGEMENT

In the name of ALLAH the most merciful and with the help of ALLAH. All good

inspirations, devotions, good expressions and prayers are to ALLAH whose blessing and

guidance have helped me throughout entire this project.

I would like to express my greatest appreciation to the all individuals who direct or

indirectly contribute their efforts and useful ideas throughout this project. My special

thanks go to my supervisors En. Mohamad Zoinol Abidin Bin Abdul Aziz for their

guidance, comments and ideas regarding to this project from the initial stage until this

stage.

My gratitude appreciation also goes to my beloved family that give a tremendous

support and great encouragement that resulted in my project progression. Special thanks

to my colleagues and friends that always give support and cooperation.

Last but not least, I like to take this opportunity to express my appreciation to all

the individuals for giving me the courage, perseverance and advice during the progression

of this project.

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ABSTRACT

An antenna is a transducer designed to transmit or receive electromagnetic waves.

A microstrip antenna is defined as an antenna which consists of radiating patch on one

side of a dielectric slab and a ground plane on the other side. A Microstrip Tri-ring

Antenna(MTA) is designed in order to obtain the mutli-frequency antenna that can

operates at frequency 2.4 GHz, 5.2GHz and 10GHz. Method of analysis that used in this

project is parametric study. This MTA is fed by coaxial probe feed and FR4 board is used

as a substrate with the specified information include the dielectric constant of substrate

( , substrate height (h=0.035mm) and loss tangent ( . The antenna has

been design using CST Microwave Studio software. The main parameters concerned are

return loss ( ) and resonant frequency. A prototype of this MTA has been built and

tested by Vector Network Analyzer (VNA). Then the measurement result obtained would

be compared to the simulation result. Troubleshooting process is carried out regarding to

the difference between both of them and would be discussed in the result part.

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ABSTRAK

Antena merupakan satu transduser yang dicipta untuk menghantar dan menerima

gelombang elektromagnetik. Antena mikrojalur didefinasikan sebagai antena yang

mengandungi radiasi patch pada salah satu sisi ‗slab‘ dielektrik dan satah bumi pada

permukaan yang lain. Antena microjalur tiga gelung ini di cipta untuk menghasilkan

antenna pelbagai frekuensi yang dapat beroperasi pada frekuensi 2.4GHz, 5.2GHz dan

10GHz. Kaedah analisis yang digunakan dalam projek ini adalah pengajian parameter.

Antena mikrojalur tiga gelung ini menggunakan teknik ‗coaxial probe feed‘ dan papan

FR4 diguna sebagai substrate dengan informasi yang khusus termasuk pemalar

dielektrik( , tinggi substrate(h=0.035mm) dan kehilangan tangent( .

Antena ini dicipta dengan menggunakan perisian computer, CST Microwave Studio.

Parameter utama yang diberi perhatian adalah dan frekuensi resonan. Prototaip

antenna mikrojalur tiga gelung ini dibina dan diukur menggunakan Vector Network

Analyzer (VNA). Kemudian keputusan pengukuran dibandingkan dengan keputusan

simulasi. Proses mengenalpasti masalah dibuat berikutan terdapatnya perbezaan diantara

kedua-duanya dan akan dibincangkan di bahagian keputusan,

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I INTRODUCTION

1.1 Overview of Antenna 1

1.2 Objective 2

1.3 Scope of Works 2

1.4 Problem Statement 3

1.5 Methodology 3

2 LITERATURE REVIEW

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2.1 Introduction of Microstrip Antenna 5

2.2 Basic Microstrip Antenna Properties 7

2.2.1 Resonance Frequency 7

2.2.2 Bandwidth 7

2.2.3 Input Impedance 8

2.2.3 Radiation Pattern 9

2.2.5 Return Loss 10

2.2.6 Power Gain 10

2.2.7 Directivity 11

2.2.8 Polarization 12

2.3 Feeding Techniques 13

2.3.1 Microstrip Line 13

2.3.2 Coaxial Probe 14

2.3.3 Aperture Coupling 14

2.3.4 Proximity Coupling 14

2.4 Advantages of Microstrip Antenna 14

2.5 Disadvantages of Microstrip Antenna 15

2.6 Applications of Microstrip Antenna 16

2.7 Method of Analysis 16

2.7.1 Transmission Line Model 16

2.7.2 Cavity Model 17

2.7.3 Full-Wave Numerical Model 18

2.7.3.1 Method of Moments (MoM) 18

2.7.3.2 Finite Element (FEM) 18

2.7.3.3 Finite Difference Time Domain (FDTD) 19

2.8 Various Types Of Ring Antenna 19

2.8.1 Square Ring Antenna 19

2.8.2 Loaded-Ring Microstrip Antenna 21

2.8.3 Microstrip Ring Antennas 22

2.8.4 Loaded Annular Ring Antennas

for Multi-Frequency Operation 23

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3 DESIGN TRI-RING ANTENNA

3.1 Design Considerations 25

3.1.1 The Dielectric Constant 25

3.1.2 Feed Substrate 26

3.1.3 Substrate Thickness 26

3.2 Design of Tri-ring Antenna 26

3.2.1 Design 1(Annular Ring Antenna) 27

3.2.1.1 The Effect By Changing The Width 27

3.2.1.2 The Effect By Changing The Location Of

Coaxial Probe Feed 29

3.2.2 Design 2(Elliptical ring antenna) 30

3.2.2.1 The Effect by Changing the Width 31

3.2.2.2 The Effect by Changing The Location Of

Coaxial Probe Feed 32

3.2.3 Design 3(Double Ring) 32

3.2.4 Design 4(Tri-ring) 34

3.3 Simulation Process 37

3.4 Fabrication Process 37

3.5 Measurement Process 38

4 RESULT AND DISCUSSION

4.1 Simulation Results 40

4.2 Measurement results 43

4.3 Comparison between Simulation and Measurement Results 44

5 CONCLUSION AND RECOMMEMDATION

5.1 Conclusion 46

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5.2 Recommendations 46

REFERENCES 47

APPENDIX A 51

APPENDIX B 52

APPENDIX C 53

APPENDIX D 54

APPENDIX E 55

APPENDIX F 56

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LIST OF FIGURE

NO. TITLE PAGE

2.1 Basic Microstrip Antenna Configuration 5

2.2 Fringing Fields within the Microstrip Antenna 6

2.3 a) Generic Dipole Elevation Pattern b) Generic Dipole Azimuth Pattern

c) 3-D Radiation Pattern 9

2.4 Example of Directional Diagram (Aperture) 12

2.5 Cavity Model 17

2.6 Geometry of Square Ring Microstrip Antenna Fed by Coupling Strip 20

2.7 Loaded Ring Microstrip Antenna 21

2.8 Microstrip Ring Antenna 22

2.9 Geometry of Loaded Annular Ring Antenna 23

3.1 The Dimension of Ring Antenna 27

3.2 The Effect By Changed The Width Of Ring Patch In Terms Of

Return Loss 28

3.3 The Effect By Changed The Width Of Ring Patch In Terms Of

Frequency 28

3.4 The Effect by Changed The Location of Coaxial Probe Feed In Terms of

Return Loss 29

3.5 The Effect by Changed The Location of Coaxial Probe Feed In Terms

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of Frequency 30

3.6 The Geometry of Elliptical Ring Antenna 30

3.7 The Effect By Changed The Width In Terms of Return Loss 31

3.8 The Effect By Changed The Width In Terms of Frequency 31

3.9 The Location of Coaxial Probe Feed 32

3.10 Combination Ring with Elliptical Shape 32

3.11 Graph of Return Loss 33

3.12 Combination Ring with Elliptical Shape 33

3.13 Graph of Return Loss 34

3.14 Changing the Location of Probe Feed for Tri-ring Antenna 34

3.15 Return Loss Graph for Three Locations of Coaxial Probe Feed 35

3.16 Changing the Width of Tri-ring Antenna 36

3.17 Return Loss by Changing the Outer Width of Tri-Ring 36

3.18 Prototype of Tri-ring Antenna 38

4.1 The Tri-ring Antenna 41

4.2 The Response for Return Loss and Frequency 41

4.3 The Radiation Pattern for 2.44GHz 42

4.4 The Radiation Pattern for 5.4GHz 43

4.5 The Radiation Pattern for 10GHz 43

4.6: Simulation Result for Tri-ring Antenna 44

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TABLE LIST

NO TITLE PAGE

4.1 Comparison between Simulation and Measurement Results 44

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ABBREVIATIONS LIST

- Reflection Coefficient

- Return Loss

- Dielectric Constant

BW - Bandwidth

CP - Circular Polarization

CST - Computer Simulation Technology

dB - Decibel

dBd - Decibels Over Dipole

dBi - Decibels Over Isotropic

EM - Electromagnetic

FDTD - Finite-Different Time Domain

FEM - Finite-Element Method

GPS - Global Positioning Satellite

h - Substrate height

l - Length

LAN - Local Area Network

Lavg - Average Circumferential Length

LHCP - Left Hand Circularly Polarized

MIC - Microwave Integrated Circuit

MoM - Method of Moments

MTA - Microstrip Tri-ring Antenna

Q - Quality Factor

R1 - Outer Radii

R2 - Inner Radii

RF - Radio Frequency

RHCP - Right Hand Circularly Polarized

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TV - Television

UV - Ultraviolet

VNA - Vector Network Analyzer

VSWR - Voltage Standing Wave Ratio

W - Width

Zin - Input Impedance

Zo - Characteristic Impedance

λ - Wavelength

- Loss tangent

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CHAPTER 1

INTRODUCTION

This chapter provides the introduction of the project, objectives, scope of work

and problem statements of this project.

1.1 Overview of Antenna

An antenna is a transducer designed to transmit or receive electromagnetic waves.

In other words, antennas convert electromagnetic radiation into electrical current, or vice

versa. Antennas generally deal in the transmission and reception of radio waves, and are a

necessary part of all radio equipment. Antennas are used in systems such as radio and

television broadcasting, point-to-point radio communication, wireless LAN, cell phones,

radar, and spacecraft communication. Antennas are most commonly employed in air or

outer space, but can also be operated under water or even through soil and rock at certain

frequencies for short distances.

Physically, an antenna is an arrangement of one or more conductors, usually called

elements in this context. In transmission, an alternating current is created in the elements

by applying a voltage at the antenna terminals, causing the elements to radiate an

electromagnetic field. In reception, the inverse occurs: an electromagnetic field from

another source induces an alternating current in the elements and a corresponding voltage

at the antenna's terminals. Some receiving antennas (such as parabolic and horn types)

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incorporate shaped reflective surfaces to collect the radio waves striking them and direct

or focus them onto the actual conductive elements.

The IEEE Standard Definitions of Terms for Antennas defined antenna as means

for radiating or receiving radios waves. In other words the antenna is the transitional

structure between free-space and a guiding device. Antenna which can work in more than

one frequency region either for transmitting or receiving electromagnetic (EM) waves are

termed as Multiband Antenna [1].

1.2 Objective

The main objective of this project is to design a tri-ring antenna that can operates

at three frequencies which are 2.4GHz, 5.4GHz and 10GHz. The other objectives of this

project are to get higher bandwidth and gain.

1.3 Scope of Works

In this project, the tri-ring microstrip antenna is designed which have opportunity

can operate at multiple frequency which are 2.4GHz, 5.4GHz and 10GHz. The simulation

is carried out until the result obtained meets the required specifications. Computer

Simulation Technology (CST) software is used for simulation to measure the parameters

(i.e. frequency, gain, bandwidth and return loss) of antenna.

Then, the process continued by fabrication process using etching technique on

FR4 board, where the actual dimension is fabricated. Vector Network Analyzer is used for

measurement to measure the parameters (i.e. frequency, gain, bandwidth and return loss)

of antenna. Finally, the comparison between the simulation and measurement results is

investigated.

1.4 Problem Statement

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With technology advancement, wireless transmission system has become

prevalent amongst electronic products. However, the traditional antenna can no longer

satisfy the needs for the transmission process of large data volume, such as the

multi-media files; therefore, an antenna with a multiple frequency is needed [16].

Microstrip patch antennas patch antenna have a disadvantage of narrow bandwidth

typically 1-5 % impedance bandwidth, dielectric and conductor losses can be large for

thin patches resulting in poor antenna efficiency and sensitivity to environmental factors

such as temperature and humidity [1].

1.5 Methodology

Appendix A represents the flow of works involved in constructing the tri-ring

antennas that can operates at multiple frequencies. Firstly, study about parameters of

antenna such as matched impedance, gain, frequency, bandwidth, return loss, amplitude of

radiation pattern and feeding technique must be taking into considerations when designing

the antenna. These parameters determine the performance of the antenna designed.

The tri-ring antenna is designed using the parametric study method. The

dimension of the ring antenna such as width and the location of the coaxial probe feed is

analyzed. The initial dimension of ring antenna is obtained from the existing ring antenna.

Then, the simulation of the design is carried out by using Computer Simulation

Technology (CST) Microwave Studio software. The effect of width, radius and location

of coaxial probe feed with return loss and frequency is analyzed. This antenna used

coaxial probe as a feeding method because the ease of matching the characteristic

impedance to that antenna.

After that, the flow of work continues with the fabrication process. This process

begins with the layout printed of tri-ring antenna. After that, the etching process is carried

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out accordingly to the antenna layout print out from the simulation. At this point, the

etching is implemented accordingly to the actual dimensions of the printed layout.

Finally, the antenna is measured using a Vector Network Analyzer (VNA) to

compare the simulations results with the measurements results.

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CHAPTER 2

LITERATURE REVIEW

This chapter explained the theory of antenna such as types of antenna, explanation

about microstrip antenna, types of feeding technique and others. This chapter also

included the review of the various ring antenna types.

2.1 Introduction of Microstrip Antenna

A microstrip antenna is defined as an antenna which consists of radiating patch on

one side of a dielectric slab and a ground plane on the other side. Figure 2.1 shows a basic

configuration of the microstrip antenna.

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Figure 2.1: Basic Microstrip Antenna Configuration [1]

Microstrip antennas are used in a broad range of applications from communication

systems such as radars, telemetry and navigation field due to their simplicity,

conformability, low manufacturing cost, and very versatile in terms of resonant frequency,

polarization, pattern and impedance at the particular patch shape and model [1].

Microstrip antennas have been used in various configurations such as square,

rectangular, circular, triangular, trapezoidal, elliptical etc. In microstrip antenna designs, it

is depends strongly on the dimensions of the patch, the location of the feed point, the

excitation frequency, the permittivity of the substrate and its thickness.

Microstrip antennas radiate due to the fringing fields between the patch and the

[image:23.595.199.414.399.560.2]

ground plane. Figure 2.6 shows the fringing fields in a microstrip patch antenna [1].

Figure 2.2: Fringing Fields within the Microstrip Antenna [1]

The fields at the end of the patch can be splited into tangential and normal

components with respect to the ground plane. The normal field components are out of

phase because the length of the patch is approximately . Therefore their contribution

to the far field in broadside direction cancels each other. The tangential field components,

which are in phase, combine to give the maximum radiated field normal to the surface of

the patch [2].

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Due to the fringing fields between the patch and the ground plane, the effective

dimensions of the antenna are greater than the actual dimensions. For example the radius

effective of the patch is greater than the physical radius. In this case fringing effect makes

the radius effective look larger due to the fact that some of the waves travel in the

substrate and some in the air [1]. Besides that, if the frequency of the wave is at a resonant

point then the electric fields around the edges have the maximum amplitude. Thus, the

radiated electric fields will be at a maximum at resonant frequencies.

2.2 Basic Microstrip Antenna Properties

In microstrip antenna, there several important properties that need to be considered

including resonance frequency, bandwidth, input impedance, radiation pattern, return loss,

directivity, gain and polarization.

2.2.1 Resonance Frequency

The resonant frequency and electrical resonance is related to the electrical length

of the antenna. The electrical length is usually the physical length of the wire multiplied

by the ratio of the speed of wave propagation in the wire. Typically an antenna is tuned

for a specific frequency, and is effective for a range of frequencies usually centered on

that resonant frequency. Antennas can be made resonant on harmonic frequencies with

lengths that are fractions of the target wavelength. Some antenna designs have multiple

resonant frequencies, and some are relatively effective over a very broad range of

frequencies [31].

2.2.2 Bandwidth

The bandwidth of an antenna is the range of frequencies over which it is effective,

usually centered around the resonant frequency. The bandwidth of an antenna may be

increased by several techniques, including using thicker wires, replacing wires with cages

Design Of Microstrip Tri-Ring Antenna.