THE E AND H ANTENNA DESIGN FOR BROADBAND APPLICATION
NURUL HANIS BINTI MOHAMAD NASIR
THE E AND H ANTENNA DESIGN FOR BROADBAND APPLICATION
NURUL HANIS BINTI MOHAMAD NASIR
This report is submitted in partial fulfillment of the requirements for the award of Bachelor of Electronic Engineering Telecommunication Electronics With Honours
Faculty of Electronic and Computer Engineering Universiti Teknikal Malaysia Melaka
UNIVERSTI TEKNIKAL MALAYSIA MELAKA
FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER
BORANG PENGESAHAN STATUS LAPORAN PROJEK SARJANA MUDA II
Tajuk Projek : THE E AND H ANTENNA DESIGN FOR BROADBAND
APPLICATION Sesi
Pengajian : 2008/2009
Saya NURUL HANIS BINTI MOHAMAD NASIR
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) (COP DAN TANDATANGAN PENYELIA)
Alamat Tetap:
LOT 1238, BATU 1, JLN MERANTI, 17000 PASIR MAS, KELANTAN.
“I hereby declare that this report is the result of my own work except for quotes as cited in the references”
Signature : ………
Author : Nurul Hanis Binti Mohamad Nasir
“I hereby declare that I have read this report and in my opinion this report is sufficient in terms of the scope and quality for the award of Bachelor of Electronic Engineering
(Telecommunication Electronics) With Honours.”
Signature : ………
Supervisor’s Name : Mr. Mohamad Zoinol Abidin Bin Abd. Aziz
ACKNOWLEDGEMENT
ABSTRACT
The major weakness of a conventional microstrip patch antenna is its narrow bandwidth. A E and H antenna is designed based on the structure of E and H itself to have a wider bandwidth to overcome this problem. The broadband characteristic is obtained by proper selecting the E and H structure. Two parallel slots and two series slots are incorporated into the patch antenna. The parallel slots reduce the size of the antenna, while the series slots reduce the return loss of the antenna. The H antenna is designed based on stepped impedance resonator while E antenna is based on transmission line model. Then, by intersecting both antennas, the E and H antenna is obtained. The E and H antenna has a compact dimension of 42.36 23.77mm2. The simulation of the antenna is carried out to obtain the return loss, bandwidth, gain, directivity and radiation pattern. Next, the antenna is fabricated on FR4 board. The E
ABSTRAK
TABLE OF CONTENTS
CHAPTER DETAILS PAGE
PROJECT TITLE i
AUTHENTICATION FORM ii
AUTHOR’S DECLARATION iii
SUPERVISOR’S DECLARATION iv
DEDICATION v
ACKNOWLEDGEMENT vi
ABSTRACT vii
ABSTRAK viii
CONTENTS ix
LIST OF TABLES xii
LIST OF FIGURES xiii
LIST OF ABBREVIATION xvi
LIST OF APPENDICES xviii
1 INTRODUCTION
1.1 Introduction 1
1.2 Objectives 2
1.3 Problem Statement 3
1.4 Scope 3
2 LITERATURE REVIEW
2.1 Fundamental Parameters of Antenna 6
2.2 Microstrip Patch Antennas 7
2.3 The E and H antenna design 8 2.3.1 L-Probe Fed Antenna 9
2.3.1.1 E-shaped Microstrip Patch 9 Antennas
2.3.1.2 A 4x1 Hybrid E-H Microstrip 11 Patch Antenna Array
2.3.2 H-shaped Patch Antenna 13 2.3.3 Wide-Band E-Shaped Patch Antennas 16 2.3.4 IHI slot antennas 18
3 E AND H MICROSTRIP ANTENNA DESIGN
3.1 Design Procedure 20
3.1.1 H antenna 21
3.1.1.1 Different impedance ratio, K design 21
3.1.2 E antenna 24
3.1.3 E and H antenna 26
3.2 Simulation Setup 27
3.2.1 H antenna simulation 28 3.2.2 E antenna simulation 29 3.2.3 E and H antenna simulation 29
3.3 Fabrication 30
4 RESULTS ANALYSIS AND DISCUSSION
4.1.1 Different impedance ratio design 33 4.1.2 Analysis of the length, L of H antenna 35 4.2 E antenna design result 40
4.2.1 Analysis of slot length, Ls 40
4.2.2 Analysis of slot position, Ps 41
4.3 E and H antenna design result 46
5 CONCLUSION AND SUGGESTIONS
5.1 Conclusion 49 5.2 Suggestions 50
REFERENCES 51
APPENDIX A 53
LIST OF TABLE
NO TITLE PAGE
3.1 The effect of varying the impedance ratio on the resonator length 22 4.1 The effect of varying the length of the H antenna 35 4.2
4.3 4.4 4.5 4.6 4.7 4.8
The return loss and bandwidth of optimized H antenna The half power beam-width for H antenna
The results for varying the slot position
Comparison of return loss between Design 1 and Design 2 The half power beam-width for E antenna
The simulation results for E and H antenna The half power beam-width for E and H antenna
LIST OF FIGURES
NO TITLE PAGE
1.1 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11
Design flow diagram for E and H antenna A rectangular microstrip patch antenna
The L-Probe Inverted E-shaped patch antenna (top view) The side view of E-shaped patch antenna
The top view of LIEH shaped patch antenna The side view of LIEH shaped patch antenna The stepped impedance resonator structure The H-shaped patch antenna
Geometry of a wide-band E-shaped patch antenna consisting of two parallel slots in the patch
The slot antenna geometries cut in a ground plane The H slot antenna geometries cut in a ground plane The IHI slot antenna geometries cut in a ground plane
4 8 9 10 12 12 13 15 17 18 18 19
3.1 The H-shaped antenna 21
3.2 Design 1 of H antenna 23
3.3 The design flow process for H-shaped antenna 23
3.4 The E-shaped antenna 24 3.5 Design 1 of E antenna 25
3.6 The design flow process for E- shaped antenna 25
3.7 The intersect process of E and H antenna 26
3.9 The side view of antenna design 28
3.10 The top view of H antenna design 28
3.11 The top view of E antenna 29
3.12 The top view of E and H antenna 30 3.13 The flow chart of fabrication process 31 3.14 The fabricated E antenna, H antenna and E and H antenna 32 4.1 The return loss for different impedance ratio 34 4.2 The return loss for Design 1 of H antenna 34 4.3 The effect of varying the L2 36
4.4 The return loss for Design 2 of H antenna 37
4.5 Design 2 of H antenna 37
4.6 Comparison of return loss between simulation and measurement 38 result for H antenna
4.7 The radiation pattern for H antenna (a) E-E plane. (b) H-H plane. 39 4.8 The changes in resonant frequency for varying the slot length 40
4.9 The graph for varying the slot position 42
4.10 Design 2 of E antenna 42
4.11 The comparison of return loss for Design 1 and Design 2 43 4.12 Comparison of return loss between simulation and 44
measurement result for E antenna
4.13 The radiation pattern for H antenna (a) E-E plane (b) H-H plane. 45 4.14 The return loss of E and H antenna 46
4.15 The comparison of return loss between simulation and 47 measurement result for E and H antenna
LIST OF ABBREVIATION
ΔL - Length extension
θ - Resonator length
ℰeff - Effective dielectric constant
ℰr - Dielectric constant
BMPAA - Broadband Microstrip Patch Antenna Array
BW - Bandwidth
CST - Computer Simulation Technology
Do - Maximum directivity
dB - Decibel
fr - Resonant frequency
FR4 - Flame Retardant 4
h - Height of dielectric substrate HPBW - Half power beam-width
IEEE - Institute of Electrical and Electronics Engineers IMT - International Mobile Telecommunication
K - Impedance ratio
L - Length
LIEH - L-Probe fed Inverted Hybrid E-H
Ls - Slot length
PCB - Printed Circuit Board
Ps - Slot position
SWR - Standing Wave Ratio
Umax - Maximum radiation intensity
UV - Ultra-violet
W - Width
LIST OF APPENDICES
NO TITLE PAGE
A Different value of K 53
CHAPTER 1
INTRODUCTION
1.1 Introduction
A novel H-shaped patch antenna is proved to have a smaller size, less number of modes, absence of harmonic resonance, and the provision of pure reactive impedances at its harmonic resonance, and the provision of pure reactive impedances at its harmonics that can result in increased transmitter efficiency [8].
In the other hand, a wide-band E-shaped patch antenna is introduced. Two parallel slots are incorporated into the patch of a microstrip antenna to expand it bandwidth. When two parallel slots are incorporated into the antenna patch, the bandwidth increases above 30% from the conventional microstrip patch antenna [9].
A novel wideband L-Probe fed inverted hybrid E-H shaped microstrip patch antenna (LIEH) covering the International Mobile Communications – 2000 (IMT-2000) band is designed that adopts contemporary techniques such as L-probe feeding, inverted patch structure with air-filled dielectric and slotted patch. The results is an antenna with an achievable bandwidth of 17.20% at 14 dB return loss (SWR=1.5) [10].
1.2 Objectives
The objectives of this project are to design an E and H shaped antenna that can operate at broadband frequencies. The suitable width and length of the desired antenna will be determine by proper selecting the E and H structure that will satisfy the broadband resonant. The return loss of the antenna is expected to be less than -10 dB and the bandwidth of the antenna is wider than the bandwidth of the conventional microstrip patch antenna.
1.3 Problem Statement
highest frequency and the lowest frequency. An antenna that has a wider bandwidth is suitable for broadband application. In addition, the antenna with smaller size is an advantage [8].
1.4 Scope
The scope of this project is to design an E and H antenna with suitable width, W
and length, L for broadband application. The simulation of return loss and bandwidth of the antenna is carried out using Computer Simulation Technology (CST) Microwave Studio. The optimization of H antenna involved its impedance ratio and resonator length. However, the optimization of E antenna involved its slot position and slot length. Next, after it satisfy the require condition, the antenna is fabricated on FR4 board using chemical etching technique. The antenna’s performance is measured such as its bandwidth, gain, directivity, return loss, radiation pattern and etc.
1.5 Methodology
Figure 1.1 Design flow diagram for E and H antenna Literature review
Measurement Design the antenna
Fabrication Simulation
CHAPTER 2
LITERATURE REVIEW
An antenna or commonly known as an aerial is defined as “a means for radiating or receiving radio waves”, from the IEEE Standard Definitions of Terms for Antennas.
In other words, an antenna is taken as the transitional structure between free space and a guiding device. There is various types of antenna for example, wire antennas, aperture antennas, microstrip antennas, array antennas, reflector antennas and lens antennas [11].
2.1 Fundamental Parameters of Antennas
The fundamental parameters of the antenna are necessary to describe the performance of the antennas. The radiation pattern of an antenna is a mathematical function or a graphical representation of the radiation properties of the antenna as a function of space coordinates. It can be determined in the far-field region and is represented as a function of the directional coordinates. The radiation properties include power flux intensity, radiation intensity, field strength, directivity phase or polarization.
In the other hand, the directivity of an antenna is defined as “the ratio of the radiation intensity in a given direction from the antenna to the radiation intensity averaged over all directions. The average radiation intensity is equal to the total power radiated by the antenna divided by 4π. If the direction is not specified, the direction of maximum radiation intensity is implied”. The directivity can be written as in equation (2.1) below rad o P U D
Dmax max
4
(2.1) where Do is the maximum directivity, Umax represents the maximum radiation intensity measured in Watt per unit solid angle, and Prad is the total radiated power measured in Watt (W) [11].
Another useful parameter that is used to describe an antenna performance is gain. The gain of an antenna is defined as
G . D (2.2) where indicates the efficiency of the antennas where is always less than the directivity. For most antenna types, the own loss is so low that G = D can be considered.
