DESIGN AND OPTIMIZATION OF DIELECTRIC RESONATOR ANTENNA ARRAY FOR C-BAND SATELLITE APPLICATIONS A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Master of Technology In Electrical Engineering BY Saurav Gupta Roll .No- 212EE1206 DEPARTMENT OF ELECTRICAL ENGINEERING NATIONAL INSTITUTE OF TECHNOLOGY ROURKELA-769008, May 2014 DESIGN AND OPTIMIZATION OF DIELECTRIC RESONATOR ANTENNA ARRAY FOR C-BAND SATELLITE APPLICATIONS A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Master of Technology In Electrical Engineering By Saurav Gupta Under the guidance of Prof P. K. Sahu DEPARTMENT OF ELECTRICAL ENGINEERING NATIONAL INSTITUTE OF TECHNOLOGY ROURKELA-769008, May 2014 NATIONAL INSTITUTE OF TECHNOLOGY ROURKELA-769008, ODISHA, INDIA CERTIFICATE This is to certify that the thesis entitled, “DESIGN AND OPTIMIZATION OF DIELECTRIC RESONATOR ANTENNA ARRAY FOR C-BAND SATELLITE APPLICATIONS” submitted by Mr. Saurav Gupta in partial fulfilment of the requirements for the award of Master of Technology Degree in ELECTRICAL ENGINEERING with specialization in “ELECTRONICS SYSTEM AND COMMUNICATION” at the National Institute of Technology, Rourkela is an authentic work carried out by him under my supervision and guidance. To the best of my knowledge, the matter embodied in the thesis has not been submitted to any other University / Institute for the award of any Degree or Diploma. Date: Prof. P. K. SAHU Dept. of Electrical Engineering National Institute of Technology Rourkela-769008 ACKNOWLEDGEMENT I express my sincere gratitude and sincere thanks to Prof. P.K. SAHU for his guidance and constant encouragement and support during the course of my Research work. I truly appreciate and values their esteemed guidance and encouragement from the beginning to the end of this works, their knowledge and accompany at the time of crisis remembered lifelong. I sincerely thank to our Director Prof. S. K. Sarangi, and all the authorities of the institute for providing nice academic environment and other facility in the NIT campus, I express my sincere thanks to Astik Biswas, Sushant Kumar Mohapatra, for their useful discussion, suggestions and continuous encouragement and motivation. Also I would like to thanks all Professors of Electrical Engineering Department who are directly and indirectly helped us. I am also thankful to all the staff members of Microwave and Antenna Laboratory for their assistance and co-operation during the course of experimental works. I also thank all my batch mates who have directly or indirectly helped me in my project work and shared the moments of joy and sorrow throughout the period of project work finally yet importantly, I would like to thank my Parents, who taught me the value of hard work by their own example. At last but not the list, I thank to all those who are directly or indirectly associated in completion of this Research work. Date: Saurav Gupta M. Tech (Electrical Engineering) Roll No -212EE1206 Electrical Engineering CONTENTS Page No Abstract....................................................................................................................................…...i List of figures……………………………………………………………………….…………….ii List of tables………………………………………………………………………………….…..iii Abbreviations used………………………………….……………...…………………………….iii CHAPTER 1: INTRODUCTION 1.1 Introduction...…………………………………………………………………………..………..2 1.2 Thesis Motivation...……………………………………………………………………...………3 1.3 Literature Review & Objective………………..………………………………………………...5 1.4Thesis Outline.………….……………………………………………………………................6 CHAPTER 2: DIELECTRIC RESONATOR ANTENNA 2.1 Introduction…………………………………………………………………………...…………9 2.2 Basic Characteristics…………………………………………………………………..………...9 2.3 Advantages…………………………………………………………………………....………..11 2.4 Feeding Methods ……………………………………………………………………………....13 2.4.1Co-axial Feed…………………………………………………………………………………14 2.4.2 Slot Aperture ………………………………………………………………………………...15 2.4.3 Micro Strip Line Feed ……………………………………………………………………….16 2.4.4 Co-Planer Feed…………………………………………………………………….…………17 2.4.5 Dielectric Image Guide…………………………………………………………….…………18 2.5 Basic-shaped Dielectric resonator antenna ……………………………………...…………19 CHAPTER 3: DESIGN OF RECTANGULAR DIELECTRIC RESONATOR ANTENNA ARRAY FOR WIRELESS AND SATELLITE APPLICATIONS 3.1Introduction………………………………………………………………………………………28 3.2 Antenna Array …………………………………………………………………………………..28 3.3 Principle of working …………………………………………………………………………….29 3.4 Controlling factors of array …………….……………………………………………………….30 3.5 Array Factor of Linear Antenna Array ………………………………………………………31 3.6 Array Factor consideration for DRA arrays …………………………………………………….32 3.7 Design of Rectangular Dielectric Resonator Antenna (DRA) Array for Wireless and Satellite Applications………………………………………………………………………………..35 3.7.1 Introduction……………………………………………………………………………………35 3.7.2. Antenna Design……………………………………………………………………………….36 3.7.3 Result and Discussions………………………………………………………………………...38 3.7.3.1 Genetic Optimization Results using MATLAB……………………………………………..40 3.8 Validation of the algorithm used………………………………………………………………...43 CHAPTER 4: CONCLUSION AND FUTURE WORK 4.1 Conclusion ……………………………………………………………………………….…….. 46 4.2 Suggestions for Future Work…………………………………………………………………….46 4.2 References………….……………………..……………………………………………………...47 Abstract The increasing use of wireless and satellite communication systems demand the antennas for different systems and standards with properties like reduced size, broadband, multiband operation, moderate gain etc. The planar and dielectric resonator antennas are the present day antenna designer‘s choice. However, conducting microstrip patch antennas inherently have a narrow bandwidth. In this thesis, a low-cost compact Dielectric Resonator Antenna array resulting Wideband characteristics with a band dispensation is presented. The antenna is implemented on FR4 substrate with a thickness of 1.6 mm and relative permittivity (εr) of 4.4. It has a partial ground plane. The antenna array is fed by the rectangular conformal patch attached to microstrip line. The reflection coefficient (S11) is less than -10 dB in 5.4 GHz−7.4 GHz frequency range with possible satellite applications. The array factor consideration for Rectangular Dielectric Resonator Antenna is also been analysed in this thesis. The proposed antenna array is then optimized using genetic optimization technique to reduce the side lobe level and at the same time to increase the directive gain of the antenna. The performance characteristics of the proposed antenna are simulated using CST microwave studio 2011TM software. The performance characteristics that have been analysed using CST microwave studio TM 2011 software are Return loss (S11), Voltage Standing Wave Ratio (VSWR) and Farfield radiation pattern plot. The ‗Roger‘ dielectric material is used for resonator having dielectric constant (εr=10.1). The dielectric material ‗Teflon‘ can also be introduces in place of roger as rogger is not easily available. The thesis contains MATLAB generated plots showing the optimization using the concept of genetic algorithm. LIST OF FIGURES Figure No. Page No. 2.1 DRAs of various shapes (cylindrical, rectangular, hemispherical, low-profile circular-disk, low-profile triangular) ……………………………………………...……11 2.2 Probe-fed Dielectric resonator antennas ……………………...…………………………..……..14 2.3 Aperture-fed Dielectric resonator antenna ……………………………………………………….15 2.4 Microstrip-fed DRA …………………………………………………...……………………............16 2.5 Co-planar loop-fed DRA ……………………………………………….…………….……………..17 2.6 Dielectric image guide-fed DRA …………………………………………..……………..….........18 2.7 The geometry of cylindrical DRA …………………………………………...…….………...........19 2.8 Configuration of a probe-fed hemispherical DRA………………………….……..………..……21 2.9 Geometry of the dielectric resonator model..........................................................................23 2.10 Normalized frequency of a rectangular DRA…………………………………….…………….25 3.1 Antenna elements placed in x-axis……………………………………………………...…………29 3.2 Antenna elements placed in y-axis……………………………………………………..………….29 3.3 Antenna elements placed in z-direction……………………………………………………..……29 3.4 Far field geometry of N-element array of isotropic sources positioned along z-axis……………………………………………………………………….………….31 3.5 - DRA geometry…………………………………………………………………………..….............34 3.6 Geometry of the proposed DRA array……………………………………………………............37 3.7 Unoptimized (a)Return loss (S11), (b) Voltage Standing Wave Ratio (VSWR), (c) Farfield directivity plots…………………………………………………………………………….38 3.8 optimised structure of antenna array……………………………………………………………..39 3.9 Optimized (a)Return loss (S11), (b) Voltage Standing Wave Ratio (VSWR), (c) Farfield directivity plots……………………………………………………………………40 3.10 Amplitude Optimization………………………………………………………………………..…..41 3.11 Distance Optimization……………………………………………………………………….....…..42 LIST OF TABLES Table No. Page No. 3.1………………………………………………………………………………43 ABBREVIATIONS USED UWB Ultra-wide band WLAN Wireless Local Area Network VSWR Voltage standing wave ratio DRA Dielectric resonator antenna RP Rectangular Conformal Patch HPBW Half Power Beam Width Chapter-1 INTRODUCTION 1 1.1 Introduction Wireless and Satellite communication was spreaded all over the world at a very good speed in the last few decades, which provides greater flexibility in the communication sector of surroundings like in hospital, several factories, and many office buildings [1], [2]. The IEEE c- band (4-8 GHz) and its slight variations