iIlllfi\1\rln~lll[ITill II II '30000002373857"

UNIVERSITI TUN HUSSEIN ONN MALAYSIA

PENGESAHAN STATUS TESIS

EQUIVALENT WIRE MODEL AND TRAVELLING WAVE MODE METHOD TO ANALYSE THE

RADIATED EMISSION OF A BENT MICROSTRIP LINE

SESI PENGAJIAN: 2008/2009

Saya VEE SEE KHEE mengaku membenarkan Tesis Sarjana ini disimpan di Perpustakaan dengan syarat-syarat kegunaan seperti berih.'ut:

I. Tesis adalah hakmilik Universiti Tun Hussein Onn Malaysia. 2. Perpustakaan dibenarkan membuat salinan untuk tujuan pengajian sahaja. 3. Perpustakaan dibenarkan membuat salinan tesis ini sebagai bahan pertukaran antara institusi

pengajian tinggi. 4. ** Sila tandakan (-/)

II II SULIT

II II TERHAD

II -/ II TIDAK TERHAD

!l'P~ L-Ul?~

(T ANDA T ANGAN PENULlS)

Alamat Tetap:

(Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia seperti yang termaktub di dalam AKT A RAHSIA RASMI 1972)

(Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasifbadan di mana penyelidikan dijalankan

Disahkan oleh

(TANrCr~ELlA)

17, JALAN RUMBIA, TAMAN DATO

ABDUL RAHMAN JAARAR, 83000 BATU

PAHAT JOHOR.

PROF. DR. MOHO. ZARAR BIN

MOHD.JENU

(Nama Penyelia)

Tarikh: 8 JUN 2009 Tarikh: 8 JUN 2009

CATATAN: ** Jika tesis sarjana ini SULIT at au TERHAD, sila lampirkan surat daripada

pihak berkuasalorganisasi berkenaan dengan menyatakan sekali scbab dan tempoh tesis ini perlu di kelaskan sebagai SULIT at au TERHAD.

"I hereby declare that I have read this thesis and in my opinion this thesis in terms of

content and quality requirements fulfill the purpose for the award of the

Master of Electrical Engineering."

Signature ~/~

............. /: .. ~ ................... .

Name of Supervisor PROF. DR. MOHD. ZARAR BIN MOHD. JENU

Date 8 JUN 2009

EQUIVALENT WIRE MODEL AND TRAVELLING WAVE MODE

METHOD TO ANALYSE THE RADIATED EMISSION OF A BENT

MICROSTRIP LINE

YEESEEKHEE

A thesis submitted in fulfillment of the requirements for the award of Master of

Electrical Engineering

Faculty of Electrical and Electronic Engineering

Universiti Tun Hussein Onn Malaysia

JUN2009

"1 hereby declare that the work in this thesis is my own except for quotations and

summaries which have been duly acknowledged"

Signature

Name of Student YEE SEEKHEE

Date 8 JUN 2009

11

III

This thesis is especially dedicated to my beloved parents.

IV

ACKNOWLEDGEMENT

Many people have contributed directly or indirectly to the completion of this

thesis and their assistance is gratefully acknowledged. First of all, I would like to

express my gratitude to my supervisor, Prof. Dr. Mohd. Zarar Bin Mohd. Jenu. His

willingness to teach attitude and unfailing patience has been a great motivation for

me to excel in my work. Without his guidance and invaluable time spent with me in

this research work, this thesis would not have been completed successfully.

I would also like to express my heartiest thankful to EMC Center staff Mr.

Mohd. Erdi Bin Ayob, Mr Saizalmursidi bin Md. Mustam, and Mr. Mohd. Nazeri

Bin Sarmijan who helps me a lot in completing my laboratory and experimental

work.

My gratitude also goes out to Prof. Marco Leone, Prof. Christos

Christopoulos, Dr. Alireza Kazemipour, Dr. Xilei Liu and Mr Chiang Chun Tung, for

their willingness in sharing their knowledge and experience regarding the

experimental works, analytical fonnulation and MICROWAVE STUDIO®

application. I would like to thanks my family members for their moral support and

blessing since the beginning. My appreciation and thanks to my friends as well for

their constructive idea, comment and critics throughout the preparation of my

research work.

I've learned along the way and it is definitely an invaluable experience later

in life. Needless to say, without all the above help and support, the writing and

production of this thesis would not have been possible. Thank you.

v

ABSTRACT

Nowadays, expeditious developments in the electrical and electronic territory due to

endless demands from the markets have driven the operation frequency of the system

into the gigahertz region. This had evolved into a more effectual-performance

system, but also inflicts a lot of difficulties to the designers, for examples

Electromagnetic Interference (EMI) problem and Signal Integrity (SI) issue. The

integrity of circuit layout is inevitably compromised by bifurcated traces for

examples T -junctions, Y -junctions, right-angle bends or left-angle-bends and steps

planar transmission lines in order to fulfil the needs of a denser printed circuit

boards. However, bifurcation often induces impedance mismatching resulting in

reflection, radiated emission and power loss. This research is to investigate the

radiated emission of 0°,45° and 90° bent microstrip lines by using an analytical

fODnulation followed by computer simulation and experimental measurements for

validation purposes. The novelty of this research is the implementation of travelling

wave mode (TWM) method on bent microstrip line by adopting the equivalent wire

model. The reliability of the formulation is proven from the agreement between the

analytical results and computer simulation, especially in predicting the E¢

component. The analytical results clearly showed the significance of the bent in

altering the radiation pattern of the microstrip line. Increasing the operating

frequency and microstrip's width tend to produce more emission. One of the electric

field components, Eo is almost symmetrical with respect to the bent angle/2 line on

the plane of the microstrip line, while the E¢ component radiates strongly into the

bent angle + bent anglel2 direction. The magnetic field on the bent microstrip line

experiences an abrupt change at the location of the bent. This change becomes

apparent as the bent angle increases. Future work should focus on improving the

analytical fornmlation so that it can predict the Eo component with higher accuracy.

FurtheDnore, effort can also be made on generating algorithm which takes into

consideration the composite electric field radiation of all the bents on a practical

printed circuit board.

'·1

ABSTRAK

Pada zaman yang begitu pesat membangun terutamanya dalam bidang

elektrik dan elektronik, pem1intaan yang semakin melambung dari pasaran telah

menaikkan operasi frekuensi sistem elektronik ke tahap gigahertz. Ini telah

memajukan sistem kepada yang lebih cekal dan effektif, tetapi ia juga mendatangkan

kesukaran dan cabaran kepada para pereka bentuk !itar seperti kesan-kesan gangguan

elektromagnet (EM I) dan isu-isu kualiti isyarat (SI). Tidak dapat dinafikan,

kewujudan pelbagai cabangan seperti cabangan-T, cabangan-Y, pembengkokkan

kekanan bersudut tegak atau pembengkokkan kekiri bersudut tegak merupakan satu

fenomena yang tidak dapat dielakkan semasa mereka !itar elektrik yang lebih padat.

Walaubagaimanapun, dwi cabang sering kali mengakibatkan galangan tak sepadan

yang menghasilkan pantulan, pancaran tersinar dan kehilangan kuasa. Dwi cabang

yang mana dipertimbangkan sebagai fenomena ketidakselanjaran adalah salah satu

penyumbang kepada ganguan kualiti isyarat. Kajian ini adalah bertujuan untuk

mengkaji pengagihan arus serta radiasi l11edan elektrik bagi satu surihan garisan jalur

mikro yang dibengkok pada 00, 45 0 dan 900 l11enggunakan analisis perumusan diikuti

oleh simulasi kOl11puter dan pengukuran eksperil11en untuk tujuan pengesahan.

Pembahruan di dalam penyelidikan ini adalah pelaksanaan kaedah mod gelombang

bergerak (TWM) pada garis surihan jalur mikro bengkok dengan mengadaptasikan

model wayar setara. Kesahihannya terbukti apabila keputusan anal isis perumusan

l11enghal11piri keputusan yang diperolehi melalui simulasi computer terutamanya bagi

E¢ komponen. Keputusan-keputusan analisis menunjukkan dengan jelas bahawa

kewujudan bengkok pada garis jalur mikro telah mcngubah corak pancaran

elektriknya. Selain itu, adalah didapati bahawa peningkatan operasi frekucnsi dan

lebar jalur mikro akan l11eningkatkan pancaran clektriknya. Salah satu komponcn

medan elektrik, Eo pada satah jalur l11ikro adalah sentiasa simetri pada arah SlIdlil

bengkok 12, l11anakala kOl11ponen medan elektrik yang lain. E¢ tcrpancar dcngan

banyak ke arah SlIdllf bcngkok + slIdlll bengkok /2. Pengagihan arus pada garisan

jalur mikro bengkok mengalami perubahan yang ketara terutamanya pada bahagian

pembengkokkan. Perubahan ini semakin ketara apabila sudut pembengkokkan

dipertingkatkan. Kajian lanjutan seharusnya memfokus pada penambahbaikkan

analisis perumusan yang sedia ada ini supaya dapat mengira komponen Eo dengan

lebih tepat. bukan itu sahaja, focus juga boleh diletakan untuk menghasilkan

algoritma baru yang mempertimbangan gabungan pancaran medan elektrik bagi

semua pembengkokkan jalur mikro di atas papan litar tercetak.

VII

CHAPTER

CHAPTER I

TABLE OF CONTENTS

CONTENTS

THESIS STATUS CONFIRMATION

SUPERVISOR'S CONFIRMATION

TITLE

TESTIMONY

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

ABSTRAK

TABLE OF CONTENTS

LIST OF FIGURE

LIST OF SYMBOLS/ABREVIATIONS

LIST OF APPENDICES

INTRODUCTION

1.1 General

1.2 Problem Statement

1.3 Aim of Research

1.4 Objectives

1.5 Scopes of Research

1.6 Importance of Research

1.7 Summary

1.8 Organisation of the Thesis

Vlll

PAG

E

11

III

IV

V

VI

V11

Xl

XVI

XIX

6

7

7

8

9

9

10

CHAPTER II REVIEW OF THE METHODS OF ANALYSIS

2.1 Introduction

2.2 Microstrip Transmission Structure

2.3 Image Theory

2.4 The Transmission-Line Equations

2.5 Derivation of Transmission-line Equations

2.6 Characteristic Impedance

2.7 Propagation Constant

2.8 The Transmission Matrix

2.9 Transmission Line Effect

2.10 Microstrip Discontinuities

2.11 Compensated Microstrip Discontinuities

2.12 Review of Important Research Works

2.13 Summary

CHAPTER III METHODOLOGY

3.1 Review of Procedures

3.2 Analytical Formulation

3.2.1 Forward-Backward Travelling Wave Mode

Method

3.2.2 Cascaded Unifoml Transmission Line Model

3.2.3 Expanded Hertzian Dipole Model

3.2.4 Equivalent Wire Model

3.3 Configuration of Computer Simulation - MICROWAVE

STUDIO®

3.3.1 Modelled Microstrip Line

3.4 Experimental Measurements

3.5 Summary

CHAPTER IV RESULTS AND DISCUSSIONS

4.1 Analytical Investigation

IX

12

12

15

18

21

22

23

23

25

26

27

28

40

41

44

44

52

57

62

65

65

70

73

75

CHAPTER V

4.1.1 Effect of Tennination Scheme

4.1.2 Effect of Operating Frequency

4.1.3 Effect of The Trace's Width

4.2 Computer Simulation

4.2.1 0° Bent Microstrip Line

4.2.2 45° Bent Microstrip Line

4.2.3 90° Bent Microstrip Line

4.3 Discussion on Electric Field Radiation

4.4 Measurements Results

4.3.1 0° Bent Microstrip Line

4.3.2 45° Bent Microstrip Line

4.3.3 90° Bent Microstrip Line

4.5 Summary

CONCLUSIONS AND SUGGESTIONS FOR FUTURE

WORK

5.1 Conclusions

5.2 Suggestions for Future Work

REFERENCES

APPENDICES

x

78

84

89

94

94

96

98

100

105

105

107

109

111

114

116

117

122

Xl

LIST OF FIGURES

FIGURE TITLE PAGE

1.1 Aspects ofEMC 2

1.2 EMC Sub-problems '"' -'

1.3 Mechanisms of Electromagnetic Interference. 4

2.1 Conceptual Evolution of a Microstrip from a Two-Wire Line 14

2.2 TE Mode and TM Mode. 15

2.3 Image of a Vertical Electric Dipole 16

2.4 Image of a Horizontal Dipole 17

2.5 Induction of (a) electric field and (b) magnetic field on the 18 transmission line.

2.6 A transmission line consists of per-unit-length inductance, I, 19 and per-unit-length capacitance, c

2.7 The telegrapher's equations are based on infinitely cascaded 20 circuit model.

2.8 The per-unit-length model for use in deriving the transmission- 21 line equation.

2.9 Two-port circuit that can be represented by a four-element 24 transmission matrix

2.10 Cascaded circuits may be represented by multiplying their 25 transmission matrices

2.11 Configuration for Compensated (a) Step-in width, (b) right- 28 angled bends, and (c) T -junction

3.1 Flowchart of the research work 43

3.2 Source and observation points on the line 47

3.3 Cascaded segments of approximate uniform transmission line 53

3.4 Illustration of the junction and segment on the cascaded 53 uniform transmission line.

3.5 Conventional Hertzian dipole model. 57

3.6

3.7

3.8

3.9

3.10

3.11

3.12

3.13

3.14

3.15

4.1

4.2

4.3

4.4

4.5

4.6

4.7

4.8

4.9

4.10

Coordinate system to calculate the electric fields from a bent

transmission line with bent angle ¢o' The microstrip structure and the equivalent wire model.

(a) 0°, (b) 45° and (c) 90° of bent microstrip line modelled by using MICROWAVE STUDIO®. (d) Ground plane 1 W peak-to-peak Gaussian signal as the input source.

Mesh view of a straight microstrip line.

Microstrip lines connected with SMA connectors and terminated with SMT resistors. Experiment Setup.

Magnetic near field probe and spectrum analyzer.

Block diagram of the experimental setup.

Movement of magnetic near field probe.

Layout of the 90° bent microstrip line.

Characteristic impedance of micros trip line with different bent angle. Propagation constant of microstrip line with different bent angle. 2D Radiation pattern of a straight microstrip line with different terminations operating in 1 GHz. 8 = 85° plane. Results are calculated based on analytical formulation. 2D Radiation pattern of a straight microstrip line with different terminations operating in 1 GHz. 8 = 45 ° plane. Results are calculated based on analytical fOTInulation. 2D Radiation pattern of a 45° bent microstrip line with different terminations operating in 1 GHz. 8 = 85 ° plane. Results are calculated based on analytical fornmlation. 2D Radiation pattern of a 45° bent microstrip line with different terminations operating in 1 GHz. 8 = 45 ° plane. Results are calculated based on analytical fornmlation. 2D Radiation pattern of a 90° bent microstrip line with different teTIninations operating in 1 GHz. 8 = 85 ° plane. Results are calculated based on analytical fOTInulation. 2D Radiation pattern of a 90° bent microstrip line with different tern1inations operating in 1 GHz. 8 = 45 ° plane. Results are calculated based on analytical formulation. Three-dimensional radiation pattern of bent microstrip lines \\lith different termination scheme operating in 1 GHz. Results are calculated based on analytical formulation. (a) Eo component of a straight microstrip line when it is

matched terminated. (b) E9 component of a straight microstrip line when it is

matched tern1inated. (c) Eo component ofa 45° bent microstrip line when it is

unmatched tern1inated.

X11

58

63

66

67

69

70

71

72

72

73

75

77

77

80

80

81

81

82

82

83

xiii

(d) Erp component of a 45° bent microstrip line when it is

unmatched tenninated.

(e) Eo component of a 90° bent microstrip line when it is open

terminated.

(f) E1' component of a 90° bent microstrip line when it is open

terminated. 4.11 2D Radiation pattern of a straight microstrip line with matched 85

tern1ination operating in 2 different frequencies. e = 85° plane. Results are calculated based on analytical formulation.

4.12 2D Radiation pattern of a straight microstrip line with 85 unmatched termination operating in 2 different frequencies. e =

45 ° plane. Results are calculated based on analytical formulation.

4.13 2D Radiation pattern of a 45° bent microstrip line with matched 86 tern1ination operating in 2 different frequencies. e = 85 ° plane. Results are calculated based on analytical forn1Ulation.

4.14 2D Radiation pattern of a 45° bent microstrip line with 86 unmatched tern1ination operating in 2 different frequencies. e =

45 ° plane. Results are calculated based on analytical fonnulation.

4.15 2D Radiation pattern of a 90° bent microstrip line with matched 87 tennination operating in 2 different frequencies. e = 85 ° plane. Results are calculated based on analytical forn1Ulation.

4.l6 2D Radiation pattern of a 90° bent microstrip line with 87 unmatched termination operating in 2 different frequencies. e =

45 ° plane. Results are calculated based on analytical forn1Ulation.

4.17 Three-dimensional radiation pattern of bent microstrip line with 88 different tern1ination scheme operating in 2 GHz. Results are calculated based on analytical forn1Ulation. (a) Eo component of a straight microstrip line when it is

unmatched tern1inated. (b) E l' component of a straight microstrip line when it is

unmatched terminated. (c) Eo component ofa 45° bent microstrip line when it is

matched tenninated. (d) E rp component of a 45° bent microstrip line when it is

matched tenninated. (e) Eo component ofa 90° bent microstrip line when it is

matched tenninated. (f) Erp component of a 90° bent microstrip line when it is

matched tenninated. 4.18 2D Radiation pattern of a straight microstrip line with different 90

width tern1inated in matched termination, operating in 1 GHz. e = 85 ° plane. Results are calculated based on analytical forn1Ulation.

4.19 2D Radiation pattern of a straight microstrip line with different 90

XIV

width terminated in open tel1nination, operating in 1 GHz, operating in 1 GHz. 8 = 45 ° plane. Results are calculated based on analytical formulation.

4.20 2D Radiation pattern of a 45° bent microstrip line with different 91 width tel111inated in matched tern1ination, , operating in 1 GHz. 8 = 85 ° plane. Results are calculated based on analytical fOl1nulation.

4.21 2D Radiation pattern of a 45° bent microstrip line with different 91 width terminated in open tern1ination, operating in 1 GHz. 8 = 45 ° plane. Results are calculated based on analytical fOl1nulation.

4.22 2D Radiation pattern of a 90° bent microstrip line with different 92 width tel1ninated in matched tern1ination, operating in 1 GHz. 8 = 85 ° plane. Results are calculated based on analytical fOl111ulation.

4.23 2D Radiation pattern of a 90° bent microstrip line with different 92 width tel1ninated in open termination, operating in 1 GHz. 8 = 45 ° plane. Results are calculated based on analytical fOl1nulation.

4.24 Three-dimensional radiation pattern of bent microstrip line with 93 strip's width = 5mm operating in 1 GHz. Results are calculated based on analytical formulation. (a) Eo component of a straight microstrip line when it is open

terminated. (b) Eq, component of a straight microstrip line when it is open

tel1ninated. (c) Eo component ofa 45° bent microstrip line when it is open

tel1ninated. (d) E¢ component of a 45° bent microstrip line when it is open

tern1inated. (e) Eo component of a 90° bent microstrip line when it is

Ulll1atched tel1ninated. (f) E¢ component of a 90° bent microstrip line when it is

unmatched tel1ninated. 4.25 Comparisons between analytical and simulation results. The 95

straight microstrip line is operating in 2 GHz with matched tel111ination. 8 = 45° plane.

4.26 Comparisons between analytical and simulation results. The 95 straight microstrip line is operating in 1 GHz with uillnatched tern1ination. 8 = 85° plane.

4.27 Comparisons between analytical and simulation results. The 96 straight microstrip line is operating in 1 GHz with open tern1ination. 8 = 45° plane

4.28 Comparisons between analytical and simulation results. The 45° 97 microstrip line is operating in 1 GHz with matched tel111ination. 8 = 45° plane.

4.29 Comparisons between analytical and simulation results. The 45° 97 microstrip line is operating in 2 GHz with unmatched

xv

termination. e = 45° plane. 4.30 Comparisons between analytical and simulation results. The 45° 98

microstrip line is operating in 1 GHz with open ternlination. e = 85° plane.

4.31 Comparisons between analytical and simulation results. The 90° 99 microstrip line is operating in 2 GHz with matched termination. e = 85° plane

4.32 Comparisons between analytical and simulation results. The 90° 99 microstrip line is operating in 1 GHz with unmatched tennination. e = 45° plane.

4.33 Comparisons between analytical and simulation results. The 90° 100 microstrip line is operating in 2 GHz with open tennination. e = 45° plane.

4.34 Different configurations of transmission structure using 103 MICROW A VE STUDIO®.

4.35 Comparison of radiation pattern of different transmission 103 structure operating in 1 GHz with matched tennination.

4.36 Comparison of radiation pattern of different transmission 104 structure operating in 2 GHz with matched tennination.

4.37 Magnetic field orientation of the 0° microstrip line and the 106 placement of magnetic near field probe.

4.38 11.1" component for a 0° bent microstrip line. 106

4.39 Magnetic field orientation of the 45° microstrip line and the 108 placement of magnetic near field probe.

4.40 11;. and H-.: component for a 45° bent microstrip line. 109

4.41 Magnetic field orientation of the 90° microstrip line and the 110 placement of magnetic near field probe.

4.42 11.1" and H-.: component for a 90° bent microstrip line. 111

B-1 Illustration of distance between source point and observation 126 point when ¢o = O.

B-2 Illustration of distance between source point and observation 127

point when ¢o = 45° .

B-3 Illustration of distance between source point and observation 128

point when ¢o = 90° .

D-1 Illustration of sections of transmission line. 135

E-1 Coordinate system of the dipole. 142

E

H

f Liz

c

l'

g

z

r OJ

VI

A

f.1

f.1o

f.1,.

c

k

lJ

LIST OF SYMBOLSI ABBREVIATIONS

Electric Field Intensity (V 1m)

Magnetic Field Intensity (Aim)

Frequency (Hz)

Smallest Length of Transmission line, (m)

Per-unit-Iength Inductance, (henry)

Per-unit-Iength Capacitance, (farad)

Per-unit-Iength Resistance, (.0)

Per-unit-Iength Conductance, (MHO)

Impedance, (.0)

Propagation Constant (m- I)

Angle Frequency (rad/s)

Scalar Potential, (volt)

Vector Potential, (Akg/m)

Relative Pennittivity (F/m)

Relative Pem1ittivity of Free-Space ( 8.854 X 1O-12F/m)

Relative Pem1ittivity of Material (dimensionless)

Relative Penneability (Him)

Relative Penneability of Free-Space (~lo=41CX 1O-7H/m)

Relative Pem1eability of Material (dimensionless)

Wavelength (m)

Velocity (m/s)

Velocity of light in fTee-space (2.998 X 108 m/s)

Wavenumber (rad/m)

Intrinsic Impedance (n)

XVI

req

/g,Slal

EMC

EMI

PCB

IC

SI

EM

FDTD

MoM

IEC

FCC

CISPR

MIC

TEM

TE

TM

HE

RF

MMICs

EFIE

EWMoM

TWM

Forward Modal Current Constant Amplitude

Backward Modal Current Constant Amplitude

Length along the Microstrip Line, (m)

Bent angle (degree)

Height of the Microstrip Line, (mm)

Width of the Microsrip Line, (mm)

Thickness of the Microstrip Line, (mm)

Equivalent Radius of the Microstrip Line, (mm)

Frequency Limit Based on Equivalent Wire Model, (GHz)

Electromagnetic Compatibility

Electromagnetic Interference

Printed Circuit Board

Integrated Circuit

Signal Integrity

Electromagnetic Simulation

Finite Difference Time Domain

Method of Moment

International Electrotechnical Commission

Federal Communications Commission's

International Special Committee for Radio Interference

Microwave Integrated Circuit

Transverse Electromagnetic

Transverse Electric

Transverse Magnetic

Hybrid Mode

Radio Frequency

Monolithic Microwave Integrated Circuits

Electric Field Integral Equation

Equivalent-wire Moment of Method

Traveling Wave Mode

X\'11

XVlll

NTL Non-uniform Transmission-line

LIST OF APPENDICES

APPENDIX ITEM

A List of Published Papers

B Distance Between the Observation Point and Source

Point Based on the Concept of Trigonometry

C

D

E

Derivation of Forward Backward Impedance and

Forward Backward Admittance with the Adoption of

Forward Backward Modal Current

Derivation of cascaded UnifoDn Transmission Line

Matrix

Derivation of Expanded Hertzian Dipole FOD1mlation

XIX

PAGE

122

124

128

133

140

CHAPTER I

INTRODUCTION

1.1 General

The strategy of marketing electrical and electronic products on time at the

lowest cost is a priority for many manufacturers. But as the operating frequency

increases, Electromagnetic Compatibility (EMC) requirements during the design

cycle and development must be addressed accordingly. EMC is defined as the ability

of device, equipment, or system to function satisfactorily in its enviromnent without

introducing intolerable electromagnetic disturbance to anything in that enviromnent

[1 ].

Consideration for EMC is now crucial for all electrical and electronic

equipments from the early stage of designing until production. New electronic

products which perform critical function will become futile if the devices do not

meet legal requirements in the countries they are to be marketed. Consequently,

Malaysian manufacturers are concemed about the EMC requirement in order to

penetrate imp0l1ant intemational markets such as United States of America,

European Union and Japan.

1