compact microstrip array antenna using...

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COMPACT MICROSTRIP ARRAY ANTENNA USING ELECTROMAGNETIC

BAND GAP (EBG)

SHARIFAH RASHIDAH BT. SYED HUSIN

This Report Is Submitted In Partial Fulfillment of Requirements for the Bachelor

Degree of Electronic Engineering (Telecommunication Electronic)

Fakulti Kejuruteraan Elektronik dan Kejuruteraan Komputer

Universiti Teknikal Malaysia Melaka

JUNE 2013

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UNIVERSTI TEKNIKAL MALAYSIA MELAKA FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER

BORANG PENGESAHAN STATUS LAPORAN

PROJEK SARJANA MUDA II

Tajuk Projek : ………………………………………………………………………………

Sesi

Pengajian : 1 2 / 1 3

Saya …………………………………………………………………………………………………..

(HURUF BESAR)

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)

Tarikh: ……………………….. Tarikh: ………………………..

COMPACT MICROSTRIP ARRAY ANTENNA USING ELECTROMAGNETIC BAND GAP (EBG)

SHARIFAH RASHIDAH BT. SYED HUSIN

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“I hereby declare that this report is the result of my own work except for quotes as cited

in the reference”

Signature :

Author : SHARIFAH RASHIDAH BT. SYED HUSIN

Date :

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“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 Honors”

Signature :

Supervisor’s Name : MR MOHD SA’ARI BIN MOHAMAD ISA

Date :

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To my beloved mother, father

and my supervisor

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ACKNOWLEDGEMENT

First, I would like to thank and praise to ALLAH S.W.T for given me the ability

to complete this report and project successfully. Without it, I would not have been able

to come this far.

I would like to express my special gratitude and thanks to my supervisor Mr

Mohd Sa’ari Bin Mohamad Isa for his advice, understanding, well guidance and help

throughout this project.

A special thanks to my family especially my parents for the encouragement and

inspiration. Not forgotten to all my fellow friends for their brilliant idea and support.

Lastly, my heart goes to all who have directly or indirectly helped me to make this

project success.

Thank you.

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ABSTRACT

This project is to develop compact array antenna integrated with electromagnetic

band gap or known as EBG to reduce mutual coupling between the arrays. The EBG

structure has unique property such as the ability to suppress the propagation of surface

wave. This structure frequently used as a part of antenna to improve the performance of

the antenna especially to improve gain, efficiency, return loss and mutual coupling. In

this project, microstrip patch antenna used because of the advantages such as cheap, easy

to fabricate and easy to integrated with microwave circuit. It involves the investigation

of microstrip patch array antenna performance when integrated with EBG. The research

is to determined performance of the antenna whether there is an improvement in the

antenna array element using EBG compared to the conventional antenna on mutual

coupling, efficiency and gain. The simulation is using CST Microwave Studio. While,

the fabrication will be use FR4 board as the substrate.

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ABSTRAK

Projek ini adalah untuk menghasilkan barisan antena yang bersaiz kecil yang

disepadukan dengan jurang jalur elektromagnetik atau dikenali sebagai EBG bagi

mengurangkan gandingan bersama diantara barisan antena. Struktur EBG mempunyai

sifat yang unik seperti keupayaanya untuk menekan penyebaran gelombang permukaan.

Struktur ini sering digunakan sebagai sabahagian daripada antena untuk meningkatkan

prestasi antena terutama untuk meningkatkan gandaan, kecekapan, return loss dan

gandingan bersama sesuatu antena. Dalam projek ini, antena mikrostrip digunakan

kerana kelebihannya seperti murah, mudah untuk membuat reka bentuk dan mudah

untuk bersepadu dengan litar mikro. Ia melibatkan penyiasatan tampalan mikrostrip

keatas prestasi barisan antena apabila disepadukan dengan EBG. Penyelidikan ini adalah

untuk menentukan prestasi antena sama ada terdapat peningkatan dalam elemen

tatasusunan antena menggunakan EBG berbanding tanpa menggunakan EBG pada

gandingan bersama, kecekapan, dan gandaan. Simulasi antena menggunakan CST

Studio Microwave dan fabrikasi akan menggunakan papan FR4 sebagai substrat.

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TABLE OF CONTENTS

CHAPTER CONTENTS PAGE

TITLE i

STATUS CONFORMATION REPORT FORM ii

DECLARATION iii

DEDICATION v

ACKNOWLEDGEMENT vi

ABSTRACT vii

ABSTRAK viii

TABLE OF CONTENTS ix

LIST OF TABLES xii

LIST OF FIGURES xiii

I INTRODUCTION

1.1 Introduction 1

1.2 Problem Statement 2

1.3 Objectives 3

1.4 Scope of Project 3

1.5 Project Planning 6

1.6 Organisation Report 7

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II LITERETURE REVIEW

2.1 Antenna 8

2.2 Antenna Properties 9

2.3 Microstrip Patch Antenna 11

2.4 Advantages and Disadvantages of Microstrip Antenna 13

2.5 Feeding Techniques 14

2.6 Radiation Mechanism 15

2.7 Microstrip Antenna Array 15

2.8 Mutual Coupling 16

2.9 Electromagnetic Band Gap (EBG) 16

2.10 Surface Wave Current 18

III METHODOLOGY

3.1 Project Methodology 20

3.2 Flow Chart 21

3.3 Literature study of the antenna 23

3.4 Design and Simulation 23

3.5 Fabrication Process 28

3.6 Measurement Process 30

IV RESULT AND DISCUSSION

4.1 Single Microstrip Patch Antenna 33

4.1.1 Calculation of Microstrip Patch Antenna 34

4.1.2 Calculation of Ground Plane size 36

4.1.3 Single Microstrip Patch Antenna Dimension and

Result

36

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4.2 Microstrip Patch Antenna Array 39

4.2.1 Simulation 41

4.2.2 Measurement 42

4.3 Electromagnetic Bandgap (EBG) 44

4.3.1 Simulation 46

4.4 Microstrip Array Antenna with EBG 48

4.4.1 Simulation 49

4.4.2 Measurement 52

4.5 Comparison between Microstrip Patch Antenna Array

with and without EBG

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V CONCLUSION

5.1 Conclusion 58

5.2 Proposed Future Work 59

REFERENCES 60

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LIST OF TABLES

NO. TITLE PAGE

4.1 Parameter of Microstrip Patch Antenna 34

4.2 Dimension of Single Patch Antenna 38

4.3 Comparison parameter of single patch antenna 39

4.4 Dimension of Antenna Array 40

4.5 Result of antenna array 42

4.6 Comparison between antenna array with and without EBG

simulation and measured.

44

4.7 Dimension of Mushroom-like EBG surface 45

4.8 Dimension of Uni-planar EBG surface 46

4.9 Dimension of antenna array with and without EBG 49

4.10 Result of microstrip antenna array with EBG 50

4.11 Comparison between antenna array with EBG simulation and

measured.

53

4.12 Comparison between antenna array with and without EBG

simulation and measured.

57

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LIST OF FIGURES

NO. TITLE PAGE

1.1 Top View 5

1.2 Front View 5

1.3 Side View 5

1.4 Flow chart of project 6

2.1 2D radiation pattern 9

2.2 Radiation lobes 10

2.3 Graph of Return Loss vs Frequency 11

2.4 Microstrip patch antenna structure 12

2.5 Various shapes of microstrip patch atenna 13

2.6 Microstrip feed line 14

2.7 Coaxial feed 14

2.8 Radiation mechanism of microstrip patch

antenna

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2.9 Various types of EBG structure 17

2.10 EBG structure 18

2.11 Propagation of surface waves in substrate 18

2.12 Propagation surface wave with and without

EBG

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3.1 Methodology flow chart 21

3.2 CST software 23

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3.3 Antenna (planar) template 25

3.4 Layout based simulation 25

3.5 Create a brick layout 25

3.6 Transient and Frequency Domain Solver

Parameters layout

26

3.7 Field monitor layout 26

3.8 S-Parameter result layout 27

3.9 Screenshot of the Impedance Calculation 27

3.10 UV light generator 28

3.11 Developer acid 29

3.12 Etching tank 29

3.13 Dryer 29

3.14 Solder iron 30

3.15 Microstrip antenna array 30

3.16 Antenna array being test with network analyser 31

3.17 Measurement setting 32

3.18 Antenna array with EBG in H and E plane 32

4.1 Single patch antenna design layout 37

4.2 Single patch antenna design layout with ground

above substrate

37

4.3 S11 of single patch antenna (formula) 38

4.4 S11 of single patch antenna (optimize) 39

4.5 Antenna array dimension 40

4.6 S-parameters of antenna array (simulation) 41

4.7 Gain of antenna array 41

4.8 Comparison S11 between simulation and

measured

43


measured

43

4.10 Mushroom-like EBG surface 45

4.11 Uni-planar surface and dimension 46

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4.12 Reflection phase of a mushroom-like EBG 47

4.13 Reflection phase of a uni-planar EBG 47

4.14 (a) Microstrip patch array antenna (b) EBG and

EBG’s ground plane

48

4.15 S-parameters of microstrip antenna array with

EBG (simulation)

49

4.16 Gain and directivity of microstrip antenna array

with EBG

50

4.17 E-Polar radiation pattern 51

4.18 E-Cross Polar radiation pattern 51

4.19 H-Polar radiation pattern 51

4.20 H-Cross Polar radiation pattern 51


measured

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measured

53

4.23 E-Polar radiation pattern 54

4.24 E-Cross Polar radiation pattern 54

4.25 H-Polar radiation pattern 54

4.26 H-Cross Polar radiation pattern 54


measured for antenna array with and without

EBG

56


measured for antenna array with and without

EBG

56

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CHAPTER 1

INTRODUCTION

1.1 Introduction

The antenna is being developed due to the popularity in a wireless

communication system and device. Antenna applied to the traditional radio, TV

broadcast and wireless communication [1]. Microstrip patch antenna is a low profile

radio antenna that is very popular in mobile and radio wireless communication. It can be

mounted on a metal ground plane and consists of a flat rectangular of metal [2].

Microstrip patch antenna has more benefit compared to conventional antenna [3]. Patch

antenna advantages such as easy to fabricate, lighter in weight, analysis, low cost and

simple feeding structure [2, 4]. Moreover, this antenna can provide circular polarization,

dual frequency operation and frequency agility [3]. However, it has narrow bandwidth,

low efficiency, low gain and surface wave losses [4].

Electromagnetic band gap (EBG) known due to their proper electromagnetic

properties which hardly to be observe in natural material and EBG structures are subsets

of metamaterials [5]. In EBG periodic and aperiodic utilize stop and progress at the

specific frequency of the electromagnetic waves propagation [1]. EBG has improved

array antenna performance by integrating electromagnetic surface with an existing

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antenna. The surface waves can be reduces if the directing electromagnetic wave

propagates along ground plane and can increase back lobe which reduce signal to noise

ratio. In addition, EBG structures reduce the mutual coupling and design low profile

antennas with good radiation efficiency [1].

Previous project consist of 2 layers EBG substrates that implement with

microstrip patch. The results produces higher gain with wider impedance bandwidth

compared to conventional patch antenna [6]. Other than that, there are 4 elements array

antenna using EBG that place on a ground plane. This structure can improve

performance in antenna array elements, return loss and VSWR [7]. Mutual coupling of

an antenna can be reduce by 2 layers EBG that provide lower resonant frequency [8].

This project will use two patch antennas and placed it above EBG. Mutual

coupling is occurring when 2 antennas placed nearer. The array element is inserted with

EBG to reduce mutual coupling [9]. In this paper, high impedance EBG is used on the

ground plane and simulates and measured microstrip patch antenna with EBG.

Simulation using CST to optimized the antenna parameters and fabricated using FR4

PCB. The frequency range of the antenna in this paper is 2.4Hz. The size of the antenna

can affect the frequency range. The antenna range with EBG ground plane is designed to

function both inside and outside the bandgap[10].

1.2 Problem Statement

Microstrip patch antenna had been used widely because of the advantages.

However it has low efficiency and high Q factors. These disadvantages are a limitation

in their application in various fields [3,4]. The major problem with microstrip patch

antenna design is the substrate surface wave propagation. The antenna efficiency will

reduce due to the surface wave propagation. This is because of the increasing of side and

back lobe [11]. Meanwhile, the antenna array will cause the mutual coupling that

defined as electromagnetic interaction between the antennas. It occurs when the

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antennas are placed nearer and cannot be placed in a very compact arrangement [12].

Mutual coupling cause some losses in power and radiation pattern in the antenna [4].

The effect of mutual coupling can be reduces by added EBG. In addition, it can suppress

the surface waves design low profile antenna with good radiation efficiency [5]. Hence

improve the radiation pattern and gain [4]. The radiation pattern and return loss will be

obtained by simulation and measurement.

1.3 Objectives

The main objective of this project is to design and develop compact microstrip array

antenna with the implemented of Electromagnetic Band Gap (EBG). The EBG structure

within the microstrip patch element will be investigate. The result is analysed by using

the simulation in CST software. Next, the performance of the array antenna will be

compared for the integration with and without electromagnetic band gap (EBG). The

design antenna structure is fabricating using FR4 PCB. Lastly, the result for both

simulation and measure is compare.

1.4 Scope of Project

This final year project is beginning with literature study regarding the topic. It

focuses on the development of the antenna to meet the desired performance that can use

in 2.4GHz.

The research is about microstrip patch antenna, array antenna and

electromagnetic band gap (EBG). Antenna efficiency, radiation pattern, gain and mutual

coupling need to be studied first for both single microstrip patch antenna and array

antenna. There are several advantages when EBG is placed on the microstrip patch

antenna. Therefore, EBG structure is the important element in this literature study.

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CST software will be used for the simulation to design microstrip patch antenna

and EBG. CST is most accurate an efficient computational to provide the variety tools

for the antenna design. Before designing antenna, obtain the frequency for antenna and

band gap. CST used to design single antenna and to optimize the result for achieving the

centre frequency of 2.4GHz. The band gap of EBG will cover the frequency of array

antenna which is 2.2GHz to 2.6GHz. From the single antenna, build array antenna. The

distance between the array antennas is varied to analyse the mutual coupling, efficiency

and gain. Moreover, CST is used to combine antenna array and EBG simulation. Place

array antenna above EBG to analyse the performance on mutual coupling, gain, return

loss and many more.

Fabrication is required after designed the antenna using CST in 2.4GHz resonant

frequency. The substrate material of the antenna is FR4 board with dielectric constant

4.3 and thickness 1.6mm. There are several steps in fabrication. The steps are printed the

layout design, expose the board to the ultra violet light, etching and lastly soldering.

The measurement process is last process in antenna designing. There are two

parts measuring the antenna. The first part is to measure antenna return loss, mutual

coupling and resonant frequency. The second part is identify radiation pattern of E

polar, H polar, E cross polar and H cross polar. Figure 1.1, 1.2 and 1.3 shows the

structures of compact microstrip array antenna using EBG for top view, front view and

side view:

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Figure 1.1: Top View.

Figure 1.2: Front View.

Figure 1.3: Side View.

Microstrip Patch Antenna

EBG


EBG


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1.5 Project Planning

The project begins with literature study according to the topic that related. The

research is about microstrip patch antenna, array antenna and electromagnetic band gap

(EBG). Specification and calculation of the antenna was obtained from the research.

After that, design single antenna, array antenna and EBG using CST software. Next,

analyse the result of comparison between the array antenna performance with and

without EBG. The fabrication process of the antenna can be done when all the

specification meets the requirement. Next process is the measurement process of both

array antenna with and without EBG. Lastly, the result between simulation and

measurement of the antenna is compared. All the experimental results are included in

this thesis report.

Figure 1.4: Flow chart of project

Start

Literature

Study

Simulation

using CST

Analyse

result

Fabrication

result

Testing and

measurements

Report

writing

End

Yes

Yes

No

No

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1.6 Organisation of Report

This report contain of five chapters which describe all the job process that has

been done in PSM 1 and PSM 2. The chapter describes as follows.

Project introduction are describe in the first chapter. This chapter includes the

objectives, problem statement, project planning and scope of projects. The work flow of

this project is set up according to objective and scope of projects.

In chapter two, it consists of literature review. The theory is based on the

microstrip patch antenna, array antenna and electromagnetic band gap (EBG).

The methodology is described in chapter 3. In this chapter it explains the steps to

complete this project. It begins with the literature review, simulation using CST software

and followed by fabrication and measurement. Design procedure of the antenna is

included in this chapter. Steps of simulation, fabrication and measurement process are

discussing in this chapter.

Chapter 4 is about result and discussion of the project. It includes the result of

measurement and simulation of the antenna. This chapter discuss regarding simulation

and measurement of single patch antenna, antenna array, electromagnetic band gap and

antenna array using EBG.

The last chapter concludes the project with suggestion of future work to improve

the antenna and EBG structure design.

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CHAPTER 2

LITERATUE REVIEW

2.1 Antenna

Antenna defined as a device that used for receiving and radiating an

electromagnetic wave in free space [13]. An antenna definition according to Webster’s

Dictionary is “a usually metallic device for receiving or radiating radio waves” [11].

Meanwhile, IEEE defines the antenna as “a means for radiating or receiving radio

waves”. In IEEE the standards used is IEEE Std 145-1983 [11]. In transmitter, an

antenna as a conductor element converts electrical energy to electromagnetic energy in

transmitter. However, in receiver it converts the electromagnetic energy to electrical

energy. There are two types of antenna which are passive antenna and active antenna.

The passive antenna is reciprocal device while, active antenna is not reciprocal devices.

The passive antenna can use for both radiation and receiving the signal. The

performance of the antenna is determined by the centre frequency, bandwidth (BW),

polarization, gain, radiation pattern and impedance [14].

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2.2 Antenna Properties

There are several properties to determine antenna performance. There are gain,

radiation pattern, efficiency, surface wave and bandwidth.

The radiation pattern is defined as a “radiation properties of the antenna in

graphical representation as a function of space coordinates” [11]. It describes of how the

antenna radiates energy and it is present in the far field. The information is presented in

the form of horizontal and vertical [11]. Radiation pattern parts are referred as lobes that

consist of major and minor as show in figure 2.2. Back lobes and side lobes are consider

as minor lobes. A radiation lobe is a part of radiation pattern that bounded by regions of

relatively weak radiation intensity. Direction of maximum radiation is major lobe.

Meanwhile, minor lobe is the undesired direction of antenna radiation [11].

Figure 2.1: 2D radiation pattern [11].

compact microstrip array antenna using...

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