DEVELOPMENT OF MICROSTRIP PATCH ARRAY ANTENNA FOR WIRELESS LOCAL AREA NETWORK
(WLAN)
AZIZAN BIN MAT HASHIM
SCHOOL OF COMPUTER AND COMMUNICATION ENGINEERING
UNIVERSITI MALAYSIA PERLIS MALAYSIA
2007
DEVELOPMENT OF MICROSTRIP PATCH ARRAY ANTENNA FOR WIRELESS LOCAL AREA
NETWORK (WLAN)
by
AZIZAN BIN MAT HASHIM
Report submitted in partial fulfillment of the requirements for the degree of Bachelor of Communication Engineering
MAY 2007
To my beloved mother:
Thank you for your understanding and giving me the chance to be what I can be.
ACKNOWLEDGEMENTS
I wish to express my thankfulness and my sincere appreciationto my supervisor Mr.
Amir Razif Arief Jamil Abdullah for his invaluable guidance, patience and support through the completion of this final year project.
My deeply gratitude to Mr. Azremi Abdullah Al- Hadi and Mr. Soh Ping Jack for their help and guidance during accomplish this project until successful. Not to forget to all my friends those also help me in order to accomplish my project.
Thank you so much to my beloved family especially my mother, Habsah Saad for your kind of understanding and moral support that never ending to me during carry out this final year project.
Finally, I would like to thank again to everyone that has been involved in this project directly or indirectly for their help and contribution.
APPROVAL AND DECLARATION SHEET
This project report titled Developments of Microstrip Patch Array Antenna for Wireless Local Area Network (WLAN) was prepared and submitted by Azizan Mat Hashim (Matrix Number: 031080626) and has been found satisfactory in terms of scope, quality and presentation as partial fulfillment of the requirement for the Bachelor of Engineering (Communication Engineering) in Universiti Malaysia Perlis (UniMAP).
Checked and Approved by
_______________________
(AMIR RAZIF ARIEF JAMIL ABDULLAH) Project Supervisor
School of Computer and Communication Engineering Universiti Malaysia Perlis
May 2007
DEVELOPMENT OF MICROSTRIP PATCH ARRAY ANTENNA FOR WIRELESS LOCAL AREA NETWORK (WLAN)
ABSTRACT
In this project, a 4x1 Rectangular Microstrip Patch Array Antenna at frequency 2.45 GHz for Wireless Local Area Network (WLAN) will be designed, fabricated and tested. The antenna will be design base on optimization and characteristics analysis. Some methods for optimize the Microstrip Patch Antenna are studied and implemented to produce the desired antenna. The objective of this project is to develop the antenna that has higher gain, higher directivity, wide bandwidth and higher efficiency. Theoretically, the objective of this project can be achieve through the use of high quality substrate such as RT Duroid 5870 which is have low relative permittivity or dielectric constant and higher substrate that will improve the bandwidth. This is due to the Rectangular Microstrip Patch Array Antenna which the bandwidth is determined by the dielectric constant and the height of substrate.
Low loss-tangent will increase the efficiency of the antenna. The patch array also has a better directivity than the single patch. Microwave Office (MWO) will be introduce as an effective tool for modeling electromagnetic structure. The antenna was fabricated based on simulation and measured using Wave and Antenna Training System (WATS2002). The expected result from this project is the antenna will has a high gain, better directivity, larger bandwidth and high efficiency.
PEMBANGUNAN ANTENNA SUSUNAN TAMPAL MIKROJALUR UNTUK RANGKAIAN TEMPATAN TANPA WAYAR (WLAN)
ABSTRAK
Di dalam projek ini, 4x1 Antena Susunan Tampal Mikrojalur Segiempat Tepat yang beroperasi pada frekuensi kendalian 2.45 GHz yang digunakan untuk rangkaian tempatan tanpa wayar akan direkabentuk, difabrikasi dan diuji. Antenna ini akan direkabentuk untuk mengoptimakan prestasi dan ciri-cirinya akan dianalisis. Beberapa kaedah untuk meengoptimumkan prestasi antena dikaji dan dipraktikkan. Objektif projek ini adalah untuk menghasilkan antenna yang mempunyai gandaan, kearahan, lebarjalur dan kecekapan yang tinggi. Secara teori, objektif projek ini dapat dicapai melalui penggunaan substrat berkualiti tinggi seperti RT Duroid 5870 yang mempunyai pemalar dielektrik dan ketinggian subtrat yang tinggi untuk menhasilkan lebarjalur yang lebih luas. Ini adalah kerana bagi Antena Tampal Mikrojalur Segiempat Tepat, lebarjalur adalah bergantung kepada pemalar dielektrik dan ketinggian substrat. Kehilangan tangen yang rendah dapat meningkatkan kecekapan antenna. Perisian Microwave Office (MWO) diperkenalkan dan digunakan untuk tujuan simulasi yang mana ianya merupakan perisian yang efektif untuk permodelan struktur elektromagnet khususnya mikrojalur. Antena ini telah difabrikasi berdasarkan kepada simulasi dan diuji menggunakan peralatan Sistem Latihan Antenna dan Gelombang (WATS 2002). Daripada projek ini, hasil yang dharapkan adalah membangunkan antenna yang mempunyai gandaan yang tinggi, kearahan yang lebih baik, lebarjalur yang lebih luas dan kecekapan yang tinggi.
TABLES OF CONTENTS
Page
DEDICATION i
ACKNOWLEDGEMENT ii
APPROVAL AND DECLARATION SHEET iii
ABSTRACT iv
ABSTRAK v
TABLE OF CONTENTS vi
LIST OF TABLES xi
LIST OF FIGURES xii
LIST OF SYMBOLS xvii
CHAPTER 1 INTRODUCTION 1.1 Introduction
1.2 Objectives and Scope 1.3 Project Introduction 1.4 Array Elements
1.5 Project Implementation Strategy 1.6 Dissertation Overview
1 1 1 2 2 3 4
CHAPTER 2 LITERATURE REVIEW 2.1 Introduction
5 5
2.2 Research Paper Literature Review
2.2.1 Design of a Multi-layer Transmit / Receive Dual-Frequency Microstrip Patch Antenna Array
2.2.2 New Considerations in the Design of Microstrip Antennas 2.2.3 Microstrip Patch Antenna Receiving Array Operating in the Ku
Band
2.2.4 Microstrip Antenna with Parasitic Elements
2.2.5 Guidelines for Design of Electromagnetically Coupled Microstrip Patch Antennas on Two-Layer Substrates 2.2.6 High-Gain Microstrip Patch Array Antenna Using a
Superstrate Layer
2.2.7 Planar Square and Diamond Microstrip Patch Array Antennas for Dual-Polarization Operation
2.3 Basic Antenna Theory 2.4 Antenna Properties
2.4.1 Impedance 2.4.2 VSWR 2.4.3 Bandwidth 2.4.4 Radiation Pattern 2.4.5 Gain
2.4.6 Polarization 2.5 Microstrip Patch Antenna
2.5.1 Introduction to Microstrip Patch Antenna 2.5.2 Operation of Microstrip Antenna
2.5.3 Shape of Microstrip Antenna 2.6 Factors Affecting Microstrip Design 2.6.1 Microstrip Discontinuity
2.6.1.1 Open End
2.6.1.2 Microstrip Line Step Discontinuity
Page 5 6
7 7
8 8
9
9
10 11 11 11 12 13 14 15 15 16 16 17 19 19 19 20
2.6.2 Fringing Field 2.6.3 Feeding Techniques
2.6.3.1 Coaxial Probe Feed 2.6.3.2 Aperture Coupling 2.6.3.3 Proximity Coupling 2.6.3.4 Microstrip Line Feed 2.6.4 Substrate Selection 2.6.5 Patch Dimensions
Page 21 22 22 23 23 24 24 25
CHAPTER 3 DESIGN OF MICROSTRIP PATCH ARRAY ANTENNA 3.1 Introduction
3.2 Design Specifications
3.3 Single Microstrip Patch Antenna Design 3.3.1 Patch Calculations
3.3.1.1 Calculation of Patch Dimension
3.3.1.2 Calculation Of The Impedance For Quarter-Wave Transformer
3.3.2 Quarter-Wave Transformer and 50 Ω Feedline Calculations 3.3.3 Radiation Pattern Calculation
3.4 Microstrip Patch Array Antenna Design 3.4.1 Array Calculation
3.4.1.1 Patch Calculation
3.4.1.2 Calculation Of The Impedance For Quarter-Wave Transformer
3.4.2 50 Ω, 70 Ω and 100 Ω Transmission Line Calculation 3.4.3 Radiation Pattern Calculation
3.5 Introduction to Microwave Office 3.5.1 Layout Based Simulation
27 27 27 29 30 30 32
33 35 35 38 38 39
39 41 41 43
Page CHAPTER 4 RESULTS AND DISCUSSION
4.1 Introduction
4.1 Characteristics of Designed Antennas 4.3 Single Patch Microstrip Antenna
4.3.1 Microwave Office Simulation 4.3.1.1 Optimization of Patch Antenna 4.3.1.2 Radiation Pattern Simulation Result 4.3.2 Measurement Results
4.3.2.1 S11 Measurement
4.3.2.2 Radiation Pattern Measurement 4.3.2.3 NetStumbler Test
4.4 Microstrip Patch Array Antenna
4.4.1 Microwave Office Simulation
4.4.1.1 Optimization of Array Antenna 4.4.1.2 Radiation Pattern Simulation Result 4.4.2 Measurement Result
4.4.2.1 S11 Measurement
4.4.2.2 Radiation Pattern Measurement 4.4.2.3 NetStumbler Test
4.5 Discussion 4.5.1 S11 Response
4.5.2 Radiation Pattern.
4.5.3 NetStumbler Result
56 56 56 57 57 58 60 62 62 64 66 68 68 69 70 71 71 72 74 76 76 79 81
CHAPTER 5 CONCLUSION 5.1 Introduction
5.2 Conclusion
5.3 Recommendation of Future Work
82 82 82 83
Page
REFERENCES 84
APPENDICES Appendix A Appendix A(i) Appendix B Appendix C Appendix D Appendix E
86 86 87 88 90 91 95
LIST OF TABLES
Tables No. Page
2.0 Common Substrate Materials for Microstrip Antenna 25
3.0 Single Patch Antenna Design Specifications 28
3.1 Dimension of Rectangular Patch Antenna 34
3.2 Dimension of Rectangular Patch Array Antenna 40
4.0 Various Dimension Effect on S11 Response 59
4.1 Optimise Dimension Versus Original Dimension (Single Patch) 59
4.2 Optimise Dimension Versus Original Dimension (Array Patch) 69
4.3 Summarization of the Single Patch Antenna 77
4.4 Summarization of the Array Patch Antenna 77
4.5 Summarization of the Radiation Pattern 80
LIST OF FIGURES
Figures No. Page
1.0 Flow Chart of the Project 3
2.0 2 X 2 Dual-Polarized Sub-arrays 6
2.1 Frequency Response for the Antenna 12
2.2 Radiation Pattern and 3dB Beamwidth 13
2.3 Rectangular Microstrip Patch Antenna 16
2.4 Circular Patch Antenna 17
2.5 Open End Equivalent Circuit 19
2.6 Open End Equivalent Circuit 20
2.7 Equivalent Circuit for Bend 20
2.8 Top View of Patch and a Demonstration of the Electric Fringing Fields that is Responsible for Radiation
21
2.9 A Side View Of Microstrip Patch Antenna and the
Demonstrating the Electric Fringing Fields 21
Page 3.0 Patch Antenna with Quarter-Wave Transformer 29
3.1 Screenshot of the Txline Calculator 33
3.2 Single Patch Antenna Design Layout 34
3.3 Example of Series Feed 36
3.4 One Dimension Parallel Feed Network 37
3.5 Four Elements Array Line Impedance Design Layout 38
3.6 Design Layout of Array Antenna 40
3.7 The Microwave Office Welcome Page 41
3.8 The Circuit Schematic Based Environment 42
3.9 The Layout Schematic Based Environment 43
3.10 The Substrate Information Option Window (Enclosure Tab) 44
3.11 The Substrate Information Option Window (Dielectric Tab) 45
3.12 The Substrate Information Option Window (Boundaries Tab) 46
3.13 The Rectangular Conductor Button Located At the Top Toolbar Used For Initial Drawing and Sizing 47
3.14 The Create Graph Pop-Up Window Option Indicating Types 48
Page
3.15 The Add Measurement Option Window 49
3.16 The Project Options Option Window 50
3.17 Add Measurement Option Windows When Adding PPC_Ephi
and PPC_Etheta 51
3.18 Exporting the Existing EM Structure 52
3.19 Re-Importing the Existing EM Structure 52
3.20 The Options Window (Frequencies Tab) 53
3.21 Selecting the E-Field Settings Option 54
3.22 Checking the Layer 1 Check Box So That E-Field Is
Computed For That Layer 54
3.23 The Analyze Button and Simulation Process Window 55
4.0 S11 Simulation Response for Original Single Patch Dimension 58
4.1 Optimize S Simulated Response 11 60
4.2 Single Patch Optimized Radiation Pattern 61
4.3 S11 Measurement Process Using Agilent E5062A Network Analyzer
63
4.4 Measured S11 Result 64
4.5
4.6
Single Patch Antenna Measurement Setup
Measured Single Patch Radiation Pattern
Page 65
65
4.7 Wireless Router Setup for NetStumbler Test 66
4.8 Single Patch Antenna NetStumbler Test Configuration 67
4.9 Single Patch Antenna NetStumbler Test Result 67
4.10 Simulated S Response for Original Array Antenna Dimensions
11 68
4.11 Optimize S Array Antenna Response 11 69
4.12 Optimized Simulated Radiation Pattern 70
4.13 Measured S11 Response for Array Antenna 71
4.14 S11 Measurement Process for Array Antenna Using Agilent E5062A Network Analyzer
72
4.15 Radiation Pattern Measurement Setup for Array Antenna 73
4.16 Measured Radiation Pattern for Array Antenna 73
4.17 Wireless Router Setup for Array Antenna 74
4.18 Microstrip Patch Array Antenna NetStumbler Testing
Configuration 75
Page 4.19 SNR versus Time for Patch Array Antenna 75
4.20 Single Patch Antenna S11 Response Simulation versus Measurement
76
4.21 Array Antenna S Response Simulation versus Measurement 11 77
4.22 Comparison of Cell Size Effect for Simulation 79
4.23 Comparison of SNR between Single Patch and Array Antenna 81
LIST OF SYMBOLS, ABBREVIATIONS OR NOMENCLATURE
c Velocity of electromagnetic waves in free space
BW Bandwidth
HPBW Half Power Bandwidth f Frequency
L Length of the Microstrip Patch Antenna w Width of the Microstrip Patch Antenna
h Substrate thickness
Q Quality factor
t Thickness of conductor
tan δ Loss tangent of dielectric material V voltage
G Gain
E Electric field
ρ Charge Density
Zin Input impedance
Zout Output Impedance
Z1 Quarterwave (λ/4) Transformer Impedance
Z0 Characteristic Impedance (Real) of the Input Transmission Line εr Relative Permittivity
εeff Effective Relative Permittivity
f0 Resonant Frequency, Operating Frequency
ΔL Fringe factor
π A constant (=3.1416) Ω Ohms
VSWR Voltage Standing Wave Ratio f/b Front to back ratio
σ Conductivity θ Angle
S 11 S-Parameter that represented an input reflection
° Degree
SNR Signal to Noise Power Ratio
