DUAL BAND ACTIVE MICROSTRIP MONOPOLE ANTENNA FOR WIRELESS LOCAL AREA NETWORK ABDULRAHMAN ABDULLAH AL-MALSI UNIVERSITI TEKNOLOGI MALAYSIA

DUAL BAND ACTIVE MICROSTRIP MONOPOLE ANTENNA FOR WIRELESS LOCAL AREA NETWORK ABDULRAHMAN ABDULLAH AL-MALSI UNIVERSITI TEKNOLOGI MALAYSIA

i DUAL BAND ACTIVE MICROSTRIP MONOPOLE ANTENNA FOR WIRELESS LOCAL AREA NETWORK ABDULRAHMAN ABDULLAH AL-MALSI A project report submitted in partial fulfillment of the requirements for the award of the degree of Master of Engineering (Electrical-Electronics & Telecommunication) Faculty of Electrical Engineering Universiti Teknologi Malaysia NOVEMBER 2009

To my beloved Father, Mother, brothers, Sisters and wife iii

iv ACKNOWLEDGEMENTS Firstly, special thanks to go to DR. SHARUL KAMAL ABDUL RAHIM for giving this opportunity to work under his supervision and for sharing his great knowledge and experience with me. Secondly, I would like to convey my deepest gratitude to Mr. Maher Bahram for his guidance to complete this research. Appreciation is also extend to all people who gave the author heartfelt corporation and shared their knowledge and for giving some their valuable time. I would like to thank Abdulqader Ali Helal. He is really a sincere and kind person. He deserves much credit for his valuable assistance and help during the early stage of this work. Also I really enjoy the discussions with him about our current research Finally, my biggest gratitude is to my family, for their endless love, emotional support and belief in me.without them I would never come up to this stage.

v ABSTRACT An active antenna with simultaneous transmit and receive function, integrate an active devices onto a printed antenna to improve its performance or combine functions within the antenna itself. Such antenna are of increasing interest, as system designers require more complex functions to be implemented in reduced space. This thesis discusses the integration of active antennas by combining receive functions into one single antenna. Two main components in the design are passive dual band microstrip monopole antenna and active device (low noise amplifier). All the simulations are done using the CST Microwave Software and Advance Design System (ADS). The terminology of active integrated antenna indicates specifically that the passive antenna elements and the active circuitry are integrated on the same substrate. Two different set of frequencies have been allocated for the WLAN application. One is at 2.4 GHz band and the other at 5.8GHz band. Two different set of frequencies need two different set of antenna. It can be solved by using one antenna for two different systems. Basically the design of transmit or receive passive microstrip monopole antenna the gain is not constant over a desired frequency band. The implementation of amplifier (low noise amplifier) in a passive antenna structure increases the antenna gain and improves the noise performance. The antenna will be designed for receiver type of amplifying active integrated microstrip monopole antenna for WLAN applications in IEEE 802.11b/g/a systems. The antenna will be fabricated on the FR4 microstrip board with r= 4.7 and tan = 0.019.The best value of the return loss at operation frequencies (ISM band) just will be less than -10 db especially after intergrades the LNA to the antenna, and also the gain just will be greater than 10 db and noise characteristics of the antenna will be enhanced(2~3db).

vi ABSTRAK Antena aktif dengan fungsi pemancaran dan penerimaan pada waktu yang sama, mengintegrasikan peralatan aktif kepada antena tercetak untuk meningkatkan keupayaan atau menggabungkan pelbagai fungsi kepada antena itu sendiri. Antena sedemikian amat diminati, di mana perekabentuk sistem memerlukan fungsi-fungsi yang lebih kompleks untuk digabungkan dalam ruang yang terhad. Kertas ini membincangkan integrasi antena aktif dengan menggabungkan fungsi-fungsi penerimaan dalam satu antena. Dua komponen utama dalam rekabentuk ialah antena mikrostrip monopole pasif dengan dua jalur dan peralatan aktif (penguat rendah hingar). Semua simulasi dilakukan melalui CST MICROWAVE SOFTWARE dan Advance Design System (ADS). Terminologi antena diintegrasi aktif menunjukkan elemen antena pasif dan litar aktif diintegrasikan pada substrat yang sama secara spesifikasi. Dua set frekuensi yang berlainan diperuntukkan untuk aplikasi WLAN. Pertama ialah jalur 2.4 GHz dan yang satu lagi ialah jalur 5.8 GHz. Dua set frekuensi yang berlainan memerlukan dua set antena yang berbeza. Ia hanya boleh diselesaikan dengan menggunakan satu antena dengan dua sistem berlainan. Secara asas gandaan pemancaran atau penerimaan rekabentuk antena monopole mikrostrip pasif tidak tetap pada jalur frekuensi yang dikehendaki. Penggunaan penguat (penguat rendah hingar) dalam struktur antena pasif meningkatkan gandaan antena dan memperbaiki keupayaan hingar. Antena direkabentuk untuk penerima bagi menguatkan antena monopole mikrostrip diintegrasi aktif untuk aplikasiaplikasi WLAN dalam sistem-sistem IEEE 802.11b/g/a. Antena akan difabrikasi pada papan mikrostrip FR4 dengan r= 4.7 dan tan = 0.019. Nilai kehilangan balikan yang terbaik pada frekuensi-frekuensi operasi (jalur ISM) memadai kurang dari -10 db terutamanya selepas integrasi penguat rendah hingar pada antena, dan juga gandaan mesti melebihi 10 db dan sifat hingar antena akan dikuatkan (2~3 db).

vii TABEL OF CONTENTS CHAPTER TITLE PAGE TITLE i DECLARATION ii DEDICATION iii ACKNOWLEDGMENT iv ABSTRACT v ABSTRAK vi TABLE OF CONTENTS vii LIST OF TABLES xii LIST OF FIGURES xiii LIST OF SYMBOLS xvi LIST OF ABBREVIATIONS xvii LIST OF APPENDICES vii 1 INTRODUCTION 1.1 Introduction 1 1.2 Problem Statement 2 1.3 Objective 3 1.4 Scope of Research 4 1.5 Research Methodology 4 1.6 Specification 5 1.7 Thesis Outline 6

viii 2 LITERATURE REVIEW 2.1 Introduction 7 2.2 Microstrip patch antenna 9 2.3 Microstrip patch antenna properties 2.3.1 Characteristic Impedance 2.3.2 Reflection coefficient 2.3.3 VSWR and Return Loss (RL) 2.3.4 Radiation pattern 2.3.5 Half Power Beamwidth (HPBW) 2.3.6 Bandwidth 2.3.7 Polarization 2.3.8 Radiating Microstrip Patch 11 11 12 12 13 16 16 17 17 2.4 Microstrip patch Antenna Application 19 2.5 Active Integrated Antennas 2.5.1 Oscillator type AIA 2.5.2 Frequency Conversion type AIA 2.5.3 Amplifier type AIA 20 21 22 22 2.6 Low Noise Amplifier 23 2.6.1 Low noise amplifier design 24 2.6.2 Gain & Noise Parameters 26 2.6.3 Quarter-wave stubs 27 2.6.4 Quarter-wave transformers 28 2.6.5 Microstrip radial stub 29 2.6.6 Amplifier s Biasing Circuit Design 30 2.7 Previous works 31 2.8 Summary 35

ix 3 DESIGN METHODOLOGY 3.1 Introduction 36 3.2 Square Patch Design Calculation for Single Frequency 36 3.3 Dual Band Active Integrated Antenna Design 42 3.4 Design Methodology 42 3.5 Materials Selection 46 3.6 Prototype Fabrication 46 3.7 Dual band microstrip monopole antenna for WLAN 46 3.7.1 Design specification of dual band microstrip monopole antenna for WLAN 46 3.7.2 Simulation of dual band microstrip monopole antenna for WLAN 3.7.3 Fabrication of dual band microstrip monopole antenna for WLAN 3.7.3.1 Generate mask on transparency 3.7.3.2 Photo exposure process 3.7.3.3 Etching in developer solution 3.7.3.4 Etching in Ferric Chloride 3.7.3.5 Soldering the probe 3.7.4 Measurement equipment 52 3.8 Low Noise Amplifier Design for Dual Operating Frequency (2.4GHz) and (5.8GHz) 52 3.8.1 Dual Band Active Integrated Antenna 53 Design 3.8.2 3.8.3 3.8.4 3.8.5 3.8.6 Specifications and design Impedance matching network Low noise Amplifier s DC Bias network Stability Analysis Schematic and layout 53 54 55 55 56 3.9 Active Antenna design 59 48 49 49 49 49 50 50

x 4 RESULTS COMPARISON AND ANALYSIS 4.1 Introduction 61 4.2 Dual-band miniaturized printed monopole antenna for wireless local area network 61 4.2.1 Layout Dimensions 62 4.2.2 Return Loss 63 4.2.3 Radiation pattern 65 4.3 Simple printed dual-band planar monopole antenna for Wireless Local Area Network 69 4.3.1 Layout Dimensions 70 4.3.2 Return Loss 71 4.3.3 Radiation pattern 72 4.4 Compact ring monopole antenna with double meander lines is proposed for wireless local area networks applications in IEEE 802.11b/g/a system 77 4.4.1 Layout Dimensions 77 4.4.2 Return Loss 78 4.4.3 Radiation pattern 80 4.5 The dual-band miniaturized printed microstrip monopole antenna for integration in modem wireless systems 84 4.5.1 Layout Dimensions 84 4.5.2 Return Loss 85 4.5.3 Radiation pattern 86 4.6 Comparison between the models 91 4.7 Simulation and results of low noise amplifier 4.7.1 GAIN (S21) at 2.4GHz and 5.8GHz 4.7.2 Return loss at (S11) 2.4GHz and 5.8GHz 4.7.3 Output return loss (S22) at 2.4 and 5.8GHz 4.7.4 Noise Figure Measurement at 2.4& 5.8GHz 91 92 93 94 94

xi 5 CONCLUSION AND FUTURE WORK 5.1 Conclusion 96 5.2 Proposed Future Works 97 REFERENCES 98 Appendices A - F 101-129

xii LIST OF TABLES TABLE NO. TITLE PAGE 3.1 Square microstrip patch antenna parameters 41 3.2 Four models of Dual Band Microstrip Monopole Antenna for WLAN 47 3.3 Low noise amplifier specification 54 4.1 Simulation result (model1) 64 4.2 Measurement result (model1) 64 4.3 Simulation result (model2) 72 4.4 Measurement result (model2) 72 4.5 Simulation result (model3) 79 4.6 Measurement result (model3) 79 4.7 Simulation result (model4) 86 4.8 Measurement result (model4) 86 4.9 The cooperation measurement result between four models 91

xiii LIST OF FIGURES FIGURE NO. TITLE PAGE 2.1 Various antennas 8 2.2 Common Shapes of Microstrip Patch Elements 9 2.3 Structure of a Microstrip Patch Antenna 10 2.4(a) Three-dimensional antenna radiation polar pattern 15 2.4(b) Two-dimensional antenna radiation pattern 15 2.5a Geometry for analyzing the Edge-Fed Microstrip Patch Antenna 18 2.5b Side view showing the electric fields 18 2.5c Top view showing the fringing electric fields that are responsible for radiation 19 2.6 Configuration of active integrated microstrip antenna 20 2.7 LNA conjugates matching 24 2.8 LNA Circuit layout 26 2.9 ADS models of open and short circuit stub 28 2.10 The layout of a radial stub 29 2.11 Amplifier biasing circuit layout 30 3.1 Structure of a patch antenna 37 3.2 Inset feed technique 40 3.3 Integrated Receiving Antennas 42 3.4 Circuit pattern on transparency 50 3.5 Photo exposure machine 50 3.6 Etching in developer solution 51 3.7 Etching in ferric chloride 51

xiv 3.8 Soldering process 51 3.9 Hand held spectrum analyzer 52 3.10 Source matching 54 3.11 Load matching 54 3.12 DC Bias network 55 3.13 ADS simulation with S2P data of the initial design 57 3.14 Linecale a utility of ADS 57 3.15 Complete schematic of low noise amplifier design with matching network 58 3.16 Layout of the low noise amplifier 59 3.17 Layout of the active antenna 60 4.1 Layout dimensions (model1) 62 4.2 Simulated and measured Return loss (model1) 64 4.3(a) Simulated E-field radiation pattern at 2.4 GHZ (model1) 65 4.3(b) Simulated H-field radiation pattern at 2.4GHZ (model1) 66 4.3(c) Simulated E-field radiation pattern at 5.8GHZ (model1) 66 4.3(d) Simulated H-field radiation pattern at 5.8GHZ (model1) 67 4.3(a) Measured E-field radiation pattern at 2.4 GHZ (model1) 67 4.4(b) Measured H-field radiation pattern at 2.4GHZ (model1) 68 4.4(c) Measured E-field radiation pattern at 5.8GHZ (model1) 68 4.4(d) Measured H-field radiation pattern at 5.8GHZ (model1) 69 4.5 Layout dimensions (model1) 70 4.6 Simulated and measured Return loss (model2) 71 4.7(a) Simulated E-field radiation pattern at 2.4 GHZ (model 2) 73 4.7(b) Simulated H-field radiation pattern at 2.4GHZ (model 2) 73 4.7(c) Simulated E-field radiation pattern at 5.8GHZ (model 2) 74 4.7(d) Simulated H-field radiation pattern at 5.8GHZ (model 2) 74 4.8(a) Measured E-field radiation pattern at 2.4 GHZ (model 2) 75 4.8(b) Measured H-field radiation pattern at 2.4GHZ (model 2) 75 4.8(c) Measured E-field radiation pattern at 5.8GHZ (model 2) 76 4.8(d) Measured H-field radiation pattern at 5.8GHZ (model 2) 76

xv 4.9 Layout dimension (model 3) 78 4.10 Simulated and measured Return loss (model3) 79 4.11(a) Simulated E-field radiation pattern at 2.4 GHZ (model 3) 80 4.11(b) Simulated H-field radiation pattern at 2.4GHZ (model 3) 80 4.11(c) Simulated E-field radiation pattern at 5.8GHZ (model 3) 81 4.11(d) Simulated H-field radiation pattern at 5.8GHZ (model 3) 81 4.12(a) Measured E-field radiation pattern at 2.4 GHZ (model 3) 82 4.12(b) Measured H-field radiation pattern at 2.4GHZ (model 3) 82 4.12(c) Measured E-field radiation pattern at 5.8GHZ (model 3) 83 4.12(d) Measured H-field radiation pattern at 5.8GHZ (model 3) 83 4.13 Layout dimensions (model 4) 84 4.14 Simulated and measured Return loss (model4) 85 4.15(a) Simulated E-field radiation pattern at 2.4 GHZ (model 4) 87 4.15(b) Simulated H-field radiation pattern at 2.4GHZ (model 4) 87 4.15(c) Simulated E-field radiation pattern at 5.8GHZ (model 4) 88 4.15(d) Simulated H-field radiation pattern at 5.8GHZ (model 4) 88 4.16(a) Measured E-field radiation pattern at 2.4 GHZ (model 4 89 4.16(b) Measured H-field radiation pattern at 2.4GHZ (model 4) 89 4.16(c) Measured E-field radiation pattern at 5.8GHZ (model 4) 90 4.16(d) Measured H-field radiation pattern at 5.8GHZ (model 4) 90 4.17 GAIN (S21) 92 4.18 Return loss (S11) 93 4.19 Output return loss (S22) 94 4.20 Noise figure 95

xvi LIST OF SYMBOLS Zo - Characteristic Impedance ZL - Load Impedance Zin - Input Impedance RL - Return Loss S11 - S parameter from port 1 to port 1 - Wavelength g or d - Dielectric guided wavelength o - Free space wavelength tan - Dielectric loss tangent f - Frequency fc - Resonant Frequency reff - Effective dielectric constant o - Dielectric constant of free space r or d - Relative Dielectric constant / permittivity W or a - Conductor width W/L - Patch conductor width over length ratio h - Height of dielectric layer I - Current V - Voltage pf / F - Piko Farade / Farade T - Reflection coeffic

xvii LIST OF ABBREVIATIONS ADS - Advanced Design System AIA - Active Integrated Antenna AIA with LNA - Active Integrated Antenna with Low Noise Amplifier BW - Bandwidth CAD - Computer Aided Design db - Decibel GHz - Giga Hertz MHz - Mega Hertz L - Length LAN - Local Area Network RF - Radio Frequency W - Width Z0 - Characteristic Impedance G - Gain LNA - Low Noise Amplifier ISM - Industrial Science Medical MIC - Microwave Integrated Circuit MMIC - Monolithic Microwave Integrated Circuit VSWR - Voltage Standered Wave Ratio RL - Return Loss HPBW - Half Power Beam Width DBS - Direct Broadcast Services EM - Electromagnetic UV - Ultraviolet NF - Noise Figure MOM - Method of Moment

xviii LIST OF APPENDICES APPENDIX TITLE PAGE A Dual-band miniaturized printed monopole antenna for wireless local area network (WLAN) 101 B Simple printed dual-band planar monopole antenna for Wireless Local Area Network (WLAN) 102 C D Compact ring monopole antenna with double meander lines is proposed for wireless local area networks (WLAN) The dual-band printed microstrip monopole antenna for integration in modem wireless systems 103 104 E F MGA-21108,Broadband Fully Integrated Matched Low-Noise Amplifier MMIC(Data sheet) Published Papers 105 126

1 CHAPTER 1 INTRODUCTION 1.1 Introduction Antenna design has become one of the most active fields in the communication studies. In the early years when radio frequency was found, simple antenna design was used as an apparatus to transmit electrical energy or radio wave through the air in all direction. Wireless technology has expanded rapidly not only for commercial but also for military purposes. Wireless technology provides less expensive alternative and a flexible way for communication. Antenna is one of the important elements in the RF system for receiving or transmitting the radio wave signals from and into the air as the medium. One of the types of antenna is the microstrip antenna. The microstrip antenna has been said to be the most innovative area in the antenna engineering, thanks to its low material cost and its easiness of fabrication which the process can be made inside universities or research institutes [1]. Wireless communications continue to enjoy exponential growth in the cellular telephony, wireless Internet, and wireless home networking arenas. The wireless networks include wireless local area networks (WLAN). The IEEE 802.11 group has been responsible for setting the standards in WLAN. One major technology exists in the

2 industrial ISM bands: 2.4-2GHz.4835 GHz, 5.15 GHz -5.35 GHz, and 5.725 GHz -5.825 GHz. Therefore the antenna is required to operate at two or more frequency bands in WLAN systems. Some of the desired features for these antennas include broad bandwidth, simple impedance matching to the feed line and low profile [2]. The terminology of active integrated antenna indicates specifically that the passive antenna elements and the active circuitry are integrated on the same substrate. Due to the mature technology of microwave integrated circuit (MIC) and monolithic microwave integrated circuit (MMIC), the active integrated antenna (AIA) became an area of growing interest in recent years Incorporation of active devices functions directly into active integrated antenna reduces the size, weight, and cost of many microwave systems [4]. Active integrated antenna can be categorized by the function of active devices they integrate. Depending on the function of the active device, the active integrated antennas can be categorized into the oscillator type, the amplifier type and the frequency conversion type [3] [5] [6] [7]. In this work, design the passive dual band microstrip antenna for wireless commutation applications in 2.4 GHz and 5.8 GHz (ISM band) bands. Low noise amplifier is integrating with the passive antenna for the purpose of enhancement the gain of the antenna and improves noise characteristics. Cost and size are reduction by using single patch microstrip antenna. 1.2 Problem Statement A WLAN access point device in the market commonly consists of a transceiver that uses one antenna for one frequency band. The use of one antenna for one frequency band increase the overall size of the access point device and the use of the monopole will have omni-directional radiation pattern. The use of microstrip antenna will be an

3 alternative to the omni-directional monopole antenna which the microstrip antenna can be used in certain cases depends on the environment. Monopole antenna has widely been used as the antenna for wireless access point because it has been a standard type of antenna for wireless devices (walkie-talkie, mobile phones, etc) and its design is less complicated than other type of antenna. omnidirectional means radiation at all angles. Two different set of frequencies have been allocated for the indoor WLAN application. One is at 2.4 GHz band and the other at 5.8GHz band. Two different set of frequencies need two different set of antenna. It can be solved by using one antenna for two different systems. The integration of two bands of frequencies can reduce the incompatibility to each other. The array antenna size is large; to make the antenna size small is by designing one patch at 2.4GHz and 5.8GHz bands. The implementation of amplifier (low noise amplifier) in a passive antenna structure increases the antenna gain and improves the noise performance. 1.3 Objectives The objectives of this project are as follows: i. To design, simulate, fabricate and measurement the performance of the passive dual band microstrip monopole antenna at ISM band (2.4GHz and 5.8 GHz). ii. To integrate the designed passive dual band microstrip monopole antenna with active device LNA (low noise amplifier) to increase the gain and improve noise characteristics.

4 1.4 Scope of Work The project focuses on the development of the antenna to meet the satisfied performance that can be used in WLAN system. The scope of this project comprises the design, simulation and fabrication between a passive dual band microstrip monopole antenna and active microstrip monopole antenna by low noise amplifier. The passive dual band microstrip monopole antenna design for wireless commutation applications in 2.4 GHz and 5.8 GHz(ISM band) bands. When the low noise amplifier is integrated with the passive antenna the antenna, the gain, noise characteristics is enhancement. The antenna is designed using CST software to obtain the overall simulation performance of the antenna. The antenna will be designed for receiver type of amplifying active integrated microstrip antenna for WLAN application 2.4 GHz and 5.8 GHz bands. The antenna will be fabricated on the FR4 microstrip board with r = 4.7 and tan = 0.019. The best value of the return loss at operation frequencies (ISM band) will be less than -10 db especially after intergrades the LNA to the antenna, and also the gain and noise characteristics of the antenna will be enhanced. 1.5 Research Methodology A Theoretical and experimental design approach was utilized to optimize the antenna structure, the strategy implemented for simplifying the design and development procedures in this research work can be divided into the following points:

5 1. Initial concept Literature review Problem statement Design conceptual understanding 2. Design and simulation stage Design consideration based on previous research results Decide the input parameters of the antenna Design the passive part of the antenna using antenna design software (CST MICROWAVE STUDIO) 3. Prototype stage Fabrication of the passive part of the designed antenna Combining the passive and active part of the proposed antenna 4. Measurement stage Measurement of the properties of the fabricated antenna 5. Analysis and conclusion stage Comparison between measurement results and the simulation results and draw a conclusion 1.6 Specification i. Antenna patch : FR4 materials r = 4.7, h (substrate thickness) = 1.6 mm T (conductor thickness) = 0.035 mm ii. Antenna resonate frequency at 2.4 GHz and 5.8 GHZ iii. Use LNA : MGA 21108 iv. Input impedance is 50 ohm v. Antenna has Rx function vi. Passive antenna Bandwidth more than 17% AT 2.4GHZ AND 26% AT 5.8GHZ

6 1.7 Thesis Outline This thesis consists of five chapters describing all the work done in the project. The thesis outline is generally described as follows. Chapter 1: This chapter explains the introduction of the project. Brief general background is presented. The objectives of the project are clearly phased with detailed. The research scope implementation plan and methodology are also presented. Chapter 2: This chapter discusses literature review. Chapter 3: This chapter gives an overview of the antenna design methodology with the fundamental process in the design, simulate, fabricate and measurement procedures. Chapter 4: This chapter discusses and analyzes the results of antenna prototype measurement compared to the simulation result. The antenna application in the real environment and comparison with monopole also presents in this chapter. Chapter 5: This chapter presents the conclusion based on the analysis and comparison of results in chapter 4. The recommendations for future works are also presented.