DEVELOPMENT OF MICROSTRIP PATCH ARRAY ANTENNA FOR WIRELESS LOCAL AREA NETWORK (WLAN) AZIZAN BIN MAT HASHIM

Transcription

1 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

2 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

3 To my beloved mother: Thank you for your understanding and giving me the chance to be what I can be.

4 ACKNOWLEDGEMENTS I wish to express my thankfulness and my sincere appreciation to 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. ii

5 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: ) 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 iii

6 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. iv

7 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. v

8 TABLES OF CONTENTS DEDICATION ACKNOWLEDGEMENT APPROVAL AND DECLARATION SHEET ABSTRACT ABSTRAK TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES LIST OF SYMBOLS i ii iii iv v vi xi xii 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 CHAPTER 2 LITERATURE REVIEW 2.1 Introduction 5 5 vi

9 2.2 Research Paper Literature Review Design of a Multi-layer Transmit / Receive Dual-Frequency Microstrip Patch Antenna Array New Considerations in the Design of Microstrip Antennas Microstrip Patch Antenna Receiving Array Operating in the Ku Band Microstrip Antenna with Parasitic Elements Guidelines for Design of Electromagnetically Coupled Microstrip Patch Antennas on Two-Layer Substrates High-Gain Microstrip Patch Array Antenna Using a Superstrate Layer Planar Square and Diamond Microstrip Patch Array Antennas for Dual-Polarization Operation 2.3 Basic Antenna Theory 2.4 Antenna Properties Impedance VSWR Bandwidth Radiation Pattern Gain Polarization 2.5 Microstrip Patch Antenna Introduction to Microstrip Patch Antenna Operation of Microstrip Antenna Shape of Microstrip Antenna 2.6 Factors Affecting Microstrip Design Microstrip Discontinuity Open End Microstrip Line Step Discontinuity Right Angle Bends vii

10 2.6.2 Fringing Field Feeding Techniques Coaxial Probe Feed Aperture Coupling Proximity Coupling Microstrip Line Feed Substrate Selection Patch Dimensions CHAPTER 3 DESIGN OF MICROSTRIP PATCH ARRAY ANTENNA 3.1 Introduction 3.2 Design Specifications 3.3 Single Microstrip Patch Antenna Design Patch Calculations Calculation of Patch Dimension Calculation Of The Impedance For Quarter-Wave Transformer Quarter-Wave Transformer and 50 Ω Feedline Calculations Radiation Pattern Calculation 3.4 Microstrip Patch Array Antenna Design Array Calculation Patch Calculation Calculation Of The Impedance For Quarter-Wave Transformer Ω, 70 Ω and 100 Ω Transmission Line Calculation Radiation Pattern Calculation 3.5 Introduction to Microwave Office Layout Based Simulation Radiation Pattern Generation viii

11 CHAPTER 4 RESULTS AND DISCUSSION 4.1 Introduction 4.1 Characteristics of Designed Antennas 4.3 Single Patch Microstrip Antenna Microwave Office Simulation Optimization of Patch Antenna Radiation Pattern Simulation Result Measurement Results S 11 Measurement Radiation Pattern Measurement NetStumbler Test 4.4 Microstrip Patch Array Antenna Microwave Office Simulation Optimization of Array Antenna Radiation Pattern Simulation Result Measurement Result S 11 Measurement Radiation Pattern Measurement NetStumbler Test 4.5 Discussion S 11 Response Radiation Pattern NetStumbler Result CHAPTER 5 CONCLUSION 5.1 Introduction 5.2 Conclusion 5.3 Recommendation of Future Work ix

12 REFERENCES 84 APPENDICES Appendix A Appendix A(i) Appendix B Appendix C Appendix D Appendix E x

13 LIST OF TABLES Tables No. 2.0 Common Substrate Materials for Microstrip Antenna Single Patch Antenna Design Specifications Dimension of Rectangular Patch Antenna Dimension of Rectangular Patch Array Antenna Various Dimension Effect on S 11 Response Optimise Dimension Versus Original Dimension (Single Patch) Optimise Dimension Versus Original Dimension (Array Patch) Summarization of the Single Patch Antenna Summarization of the Array Patch Antenna Summarization of the Radiation Pattern 80 xi

14 LIST OF FIGURES Figures No. 1.0 Flow Chart of the Project X 2 Dual-Polarized Sub-arrays Frequency Response for the Antenna Radiation Pattern and 3dB Beamwidth Rectangular Microstrip Patch Antenna Circular Patch Antenna Open End Equivalent Circuit Open End Equivalent Circuit Equivalent Circuit for Bend Top View of Patch and a Demonstration of the Electric Fringing Fields that is Responsible for Radiation A Side View Of Microstrip Patch Antenna and the Demonstrating the Electric Fringing Fields 21 xii

15 3.0 Patch Antenna with Quarter-Wave Transformer Screenshot of the Txline Calculator Single Patch Antenna Design Layout Example of Series Feed One Dimension Parallel Feed Network Four Elements Array Line Impedance Design Layout Design Layout of Array Antenna The Microwave Office Welcome The Circuit Schematic Based Environment The Layout Schematic Based Environment The Substrate Information Option Window (Enclosure Tab) The Substrate Information Option Window (Dielectric Tab) The Substrate Information Option Window (Boundaries Tab) The Rectangular Conductor Button Located At the Top Toolbar Used For Initial Drawing and Sizing The Create Graph Pop-Up Window Option Indicating Types of Graphs 48 xiii

16 3.15 The Add Measurement Option Window The Project Options Option Window Add Measurement Option Windows When Adding PPC_Ephi and PPC_Etheta Exporting the Existing EM Structure Re-Importing the Existing EM Structure The Options Window (Frequencies Tab) Selecting the E-Field Settings Option Checking the Layer 1 Check Box So That E-Field Is Computed For That Layer The Analyze Button and Simulation Process Window S 11 Simulation Response for Original Single Patch Dimension Optimize S Simulated Response Single Patch Optimized Radiation Pattern S 11 Measurement Process Using Agilent E5062A Network Analyzer Measured S 11 Result 64 xiv

17 4.5 Single Patch Antenna Measurement Setup Measured Single Patch Radiation Pattern Wireless Router Setup for NetStumbler Test Single Patch Antenna NetStumbler Test Configuration Single Patch Antenna NetStumbler Test Result Simulated S Response for Original Array Antenna Dimensions 4.11 Optimize S Array Antenna Response Optimized Simulated Radiation Pattern Measured S 11 Response for Array Antenna S 11 Measurement Process for Array Antenna Using Agilent E5062A Network Analyzer Radiation Pattern Measurement Setup for Array Antenna Measured Radiation Pattern for Array Antenna Wireless Router Setup for Array Antenna Microstrip Patch Array Antenna NetStumbler Testing Configuration 75 xv

18 4.19 SNR versus Time for Patch Array Antenna Single Patch Antenna S 11 Response Simulation versus Measurement Array Antenna S 11 Response Simulation versus Measurement Comparison of Cell Size Effect for Simulation Comparison of SNR between Single Patch and Array Antenna 81 xvi

19 LIST OF SYMBOLS, ABBREVIATIONS OR NOMENCLATURE c BW HPBW f L w h Q t tan δ V G E ρ Z in Velocity of electromagnetic waves in free space Bandwidth Half Power Bandwidth Frequency Length of the Microstrip Patch Antenna Width of the Microstrip Patch Antenna Substrate thickness Quality factor Thickness of conductor Loss tangent of dielectric material voltage Gain Electric field Charge Density Input impedance Z Output Impedance out Z 1 Z 0 ε r ε eff f 0 ΔL R in Quarterwave (λ/4) Transformer Impedance Characteristic Impedance (Real) of the Input Transmission Line Relative Permittivity Effective Relative Permittivity Resonant Frequency, Operating Frequency Fringe factor Resistance at the edge of the patch xvii

20 π A constant (=3.1416) Ω VSWR f/b σ θ Ohms Voltage Standing Wave Ratio Front to back ratio Conductivity Angle S S-Parameter that represented an input reflection 11 Degree SNR Signal to Noise Power Ratio xviii