DEVELOPMENT OF A FREQUENCY MODULATED

CONTINUOUS WAVE RADAR FOR SLOW MOVING

TARGET DETECTION

BY

NOR FATIN BINTI MUHD ARIFFIN

A thesis submitted in fulfilment of the requirement for the

degree of Master of Science (Communication Engineering)

Kulliyyah of Engineering

International Islamic University Malaysia

JULY 2017

ii

ABSTRACT

Frequency Modulated Continuous Wave (FMCW) radar system is frequently used for

remote sensing applications which require high sensitivity and continuous monitoring.

There are many factors that affected the radar’s performance; they are including

applied techniques, characteristic of detecting a target and experimental environment.

Those factors also provide the impact on the expenses of the radar fabrication. This

research aims to develop an inexpensive S-band FMCW radar with radar sensitivity

improvement for slow moving target applications. The pre-design phase of the radar is

simulated in Advanced Design System (ADS) 2014 software to find the radar’s

breakthrough. The proposed radar operates at 2.4GHz carrier frequency with

10.41dBm transmit power. It established a 2.8m range resolution from 53.2MHz

bandwidth. A computer-based system is used for Data Acquisition (DAQ) system and

digitalized signal process. Chirp period-bandwidth product of Frequency Modulated

(FM) waveform and deramping process with maximum range of 200meters and Radar

Cross Section (RCS), 𝜎 of 1m2 improve the radars’ Signal to Noise Ratio (SNR) by

42dB. Next, the radar is tested in several experiments to evaluate the capability of the

radar to determine range and velocity of the slow moving target. The experiments are

conducted in a Microwave Laboratory of International Islamic University Malaysia.

Fast Fourier Transform (FFT) method is used for analog to digital conversion.

Additionally, Moving Target Indicator (MTI) - chirp cancellor technique is

implemented on ranging measurement for clutter rejection. Based on the conducted

experiments, the radar proves that it is able to detect the target that moves at very slow

speed. It provides accurate measurement for a target which moves more than 1m/s

speed with a 6.73% percentage error. It also achieves an accurate and precise range

measurement for slow moving target detection with 0.18% percentage error. Hence,

the proposed FMCW radar design is capable to provide high sensitivity performances

despite its low-cost fabrication.

iii

خلاصة البحثABSTR ARABIC

)ا كثير الرادارالموجيالمتواصلالتردد نظام يستخدم لتطبيقاتاFMCWما ستشعارعنلإ(

التي العوامل من العديد هناك مستمر. ورصد عالية تتطلبحساسية التي أداءتؤثربعد على

الهدفوالبيئة الكشفعن وميزة التقنياتالتطبيقية، تشمل فهي هذهالرادار. تؤثر التجريبية.

تطوير إلى البحث هذا يهدف الرادار. تصنيع نفقات على أيضا مكلف العوامل للمدىغير

معتحسينحساسيةالرادارلتطبيقاتالهدفبطيئالحركة. رادار(FMCW)لنظام Sالترددي

التصميم قبل ما مرحلة محاكاة )نظاملرادارفيليتم المتقدم ADS)2014برمجياتالتصميم

إرسالبقوهو 2.4GHZبتردد ناقلعلىختراقالرادار.الرادارالمقترحيعملإللعثورعلى

53.2عرضالنطاقتردديمنمتر2.8نطاقعندالراداردقهتثبيتتم.dBm 10.41تساوي

رض.عرقميا الإشارةمعالجهقتناءالبياناتولأ (DAQ)حاسوبينظاماستخدامتمميجاهرتز.

التخميدمعالجه(وعمليةFM)التردديالموجيمنالتضمينChirp period النطاقالتردديا

أقصىمدىمن 200مع متر سطحمساحهعند 𝜎 of 1m ,(RCS) الرادار2نسبهيحسن

الىالإشاره SNR)للرادارالضجيج بنسبة )42 dB. يتم ذلك، عدةإبعد في الرادار ختبار

التجاربفيإجراءتمتحديدمدىوسرعةالهدفبطيئالحركة.علىةالرادارتجاربلتقييمقدر

ماليزيا.يتماستخدامطريقةالعالميةفيالجامعةالإسلاميةالهندسهكليهفيمختبرالميكروويف

فوريي رتحويل (FFT)السريع إلىإشاراتإلىالتماثليهالإشاراتلتحويل بالإضافة رقمية.

تراوحلرفضالعلىقياسنفذت chirp cancellor-(MTIحركمؤشرالهدف)تتقنيهذلك،

استناد الجلبة. قادرعلىالكشفعنالهدفالذيالراداراثبتإلىالتجاربالتيأجريت، أنه

يتحركبسرعةبطيئةجدا بسرعههدفالذييتحركلأنهيوفرقياسدقيقلاثبتالراداركما.

ن 1m/sمنأكثر مع الخطأ 6.73سبة يحققدقة أنه كما للكشفعنالمحددالمدىقياسل٪.

معالهدفبطيئالحركة للمئويةنسبة 0.18خطأ وبالتالي، فإن٪. FMCWرادارتصميم

توفيرأداءحساسيةعاليةعلىالرغممنتصنيعهمنخفضالتكلفة المقترحقادرعلى

iv

APPROVAL PAGE

I certify that I have supervised and read this study and that in my opinion, it conforms

to acceptable standards of scholarly presentation and is fully adequate, in scope and

quality, as a thesis for the degree of Master of Science (Communication Engineering).

…………………………………..

Farah Nadia Mohd Isa

Supervisor

…………………………………..

Ahmad Fadzil Ismail

Co-Supervisor

I certify that I have read this study and that in my opinion it conforms to acceptable

standards of scholarly presentation and is fully adequate, in scope and quality, as a

thesis for the degree of Master of Science (Communication Engineering).

…………………………………..

Nurul Fadzlin Hasbullah

Internal Examiner

…………………………………..

Aduwati Sali

External Examiner

This thesis was submitted to the Department of Electrical and Computer Engineering

and is accepted as a fulfilment of the requirement for the degree of Master of Science

(Communication Engineering).

…………………………………..

Anis Nurashikin Nordin

Head, Department of Electrical

and Computer Engineering

This thesis was submitted to the Kulliyyah of Engineering and is accepted as a

fulfilment of the requirement for the degree of Master of Science in Communication

Engineering

…………………………………..

Erry Yulian T. Adesta

Dean, Kulliyyah of Engineering

v

DECLARATION

I hereby declare that this dissertation is the result of my own investigations, except

where otherwise stated. I also declare that it has not been previously or concurrently

submitted as a whole for any other degrees at IIUM or other institutions.

Nor Fatin Binti Muhd Ariffin

Signature ........................................................... Date .........................................

vi

PAGE

INTERNATIONAL ISLAMIC UNIVERSITY MALAYSIA

DECLARATION OF COPYRIGHT AND AFFIRMATION OF

FAIR USE OF UNPUBLISHED RESEARCH

DEVELOPMENT OF A FREQUENCY MODULATED

CONTINUOUS WAVE RADAR FOR SLOW MOVING TARGET

DETECTION

I declare that the copyright holders of this dissertation are jointly owned by the student

and IIUM.

Copyright © 2017 Nor Fatin Binti Muhd Ariffin and International Islamic University Malaysia. All

rights reserved.

No part of this unpublished research may be reproduced, stored in a retrieval system,

or transmitted, in any form or by any means, electronic, mechanical, photocopying,

recording or otherwise without prior written permission of the copyright holder

except as provided below

1. Any material contained in or derived from this unpublished research may

be used by others in their writing with due acknowledgement.

2. IIUM or its library will have the right to make and transmit copies (print

or electronic) for institutional and academic purposes.

3. The IIUM library will have the right to make, store in a retrieved system

and supply copies of this unpublished research if requested by other

universities and research libraries.

By signing this form, I acknowledged that I have read and understand the IIUM

Intellectual Property Right and Commercialization policy.

Affirmed by Nor Fatin Binti Muhd Ariffin

……..…………………….. ………………………..

Signature Date

vii

ACKNOWLEDGEMENTS

All praise to Allah SWT, the Almighty for bestowing His Grace and Mercy for

granting me the strength to carry out and accomplish the completion of this thesis

throughout the duration of my programme although it has been tasking.

Firstly, it is my utmost pleasure to dedicate this work to my dear parents;

Muhd Ariffin Che Hasan and Zainab Mat Deris, who granted me the gift of their

unwavering belief in my ability to accomplish this goal: thank you for your support

and patience.

I would like to express my deepest appreciation and gratitude to my

supervisor, Assistant Professor Farah Nadia Mohd Isa for her continuous guidance,

support, and encouragement. My appreciation also goes to my co-supervisor,

Associate Professor Ir. Dr. Ahmad Fadzil Ismail for giving me an opportunity to

conduct this thesis, allowing me to use the lab equipment and giving me lab access to

do this thesis. For these, I will be forever grateful.

Finally, I wish to thank to those who provided their time, effort and support for

this Master research especially IIUM technician, Brother Sapora.

viii

TABLE OF CONTENTS

Abstract .................................................................................................................... ii Abstract in Arabic .................................................................................................... iii Approval Page .......................................................................................................... iv

Declaration ............................................................................................................... v Copyright Page ......................................................................................................... vi Acknowledgements .................................................................................................. vii List of Tables ........................................................................................................... x List of Figures .......................................................................................................... xi

List of Abbreviations ............................................................................................... xv

List of Symbols ........................................................................................................ xi

CHAPTER ONE: INTRODUCTION ................................................................. 1 1.1 Overview................................................................................................. 1 1.2 Research Problem Statement .................................................................. 4 1.3 Research Objectives................................................................................ 5

1.4 Research Methodology ........................................................................... 5 1.5 Research Scope ....................................................................................... 7

1.6 Thesis Organization ................................................................................ 8

CHAPTER TWO: LITERATURE REVIEW .................................................... 10 2.1 Introduction............................................................................................. 10 2.2 Basic Radar ............................................................................................. 10

2.2.1Transmit Power .............................................................................. 10

2.2.2 Signal Detection ............................................................................ 11

2.2.3 Range Resolution .......................................................................... 12 2.2.4 Radar Cross Section ...................................................................... 13

2.2.1 Radar Antenna............................................................................... 14 2.3 Related Works ........................................................................................ 16

2.3.1 CW Doppler Radar........................................................................ 16

2.3.2 FMCW Radar ................................................................................ 18 2.3.2.1 Basic Principle of FMCW Radar ...................................... 18

2.3.2.2 FMCW Doppler Radar ..................................................... 20

2.3.2.3 Advantages of FMCW Doppler Radar ............................. 23

2.3.3 Current FMCW Radar for Slow Moving Target .......................... 26

2.3.3.1 Modern FMCW Radar ...................................................... 26

2.3.3.2 FMCW Phased Array Radar ............................................. 28

2.3.3.3 FMCW MIMO Radar ....................................................... 31

2.3.3.4 FMCW SAR Radar ........................................................... 34

2.4 Summary ................................................................................................. 35

CHAPTER THREE: RESEARCH METHODOLOGY ................................... 37 3.1 Introduction............................................................................................. 37 3.2 Radar Design Approaches ...................................................................... 37

3.2.1 Operating Frequency ..................................................................... 37 3.2.2 Antenna and Operational Platform ............................................... 38

ix

3.2.3 Target Backscatterer Coefficient .................................................. 39

3.2.4 Data Acquistion (DAQ) System ................................................... 40

3.2.5 Ranging Digital Signal Processing .............................................. 41

3.2.6 Velocity Digital Signal Processing ............................................... 44

3.3 Proposed FMCW Radar Hardware Architecture .................................... 46

3.4 Experimental Test Site ............................................................................ 50

3.5 Summary ................................................................................................. 51

CHAPTER FOUR: FMCW RADAR DESIGN AND SIMULATION

ANALYSIS ............................................................................................................. 52 4.1 Introduction............................................................................................. 52 4.2 Simulation of FM Chirp Waveform ....................................................... 52 4.3 Simulation of Transmitter Radar System ............................................... 56

4.3.1 Power Amplifier and Selected Initial Parameters ......................... 57

4.3.2 Transmitter Design System and Performance Analysis ................ 62

4.4 Complete FMCW Radar Design and Performance Analysis ................. 65

4.4.1 Radar Performance Analysis on a Static Target Detection ........... 66

4.4.2 Radar Performance Analysis on a Moving Target ........................ 68

4.5 Summary ................................................................................................. 72

CHAPTER FIVE: RADAR TRIALS AND MEASUREMENTS ..................... 73 5.1 Introduction............................................................................................. 73 5.2 Radar Hardware Architecture Path Links Measurement Analysis ......... 73 5.3 Experiment 1: Radar Performance detection capability ......................... 78

5.4 Experiment 2: Investigate the Capability of Radar to Measure Slow

Moving Target’s Velocity at 4meters Maximum range ......................... 80

5.5 Experiment 3: Investigate the Capability of Radar to Measure Slow

Moving Target’s Velocity at 16meters Maximum range ....................... 82

5.6 Experiment 4:Measured Speed Establishement for Different Type of

Targets .................................................................................................... 84 5.7 Experiment 5: Range Measurement of Moving Target at Maximum

Range of 13.735meters .......................................................................... 87

5.8 Summary ................................................................................................. 90

CHAPTER SIX: CONCLUSION AND FUTURE WORK ............................... 91 6.1 Conclusion .............................................................................................. 91

6.2 Future Work ............................................................................................ 92

REFERENCES ....................................................................................................... 94

PUBLICATIONS ................................................................................................... 99

APPENDIX A: TARGET MODEL .................................................................... 100 APPENDIX B: MATHEMATICAL CALCULATION ..................................... 101

APPENDIX C: RADAR TRIALS ...................................................................... 103

x

LIST OF TABLES

Table No. Page No.

‎2.1 Mean RCS Values for Selected Objects 14

‎2.2 Summary of The Advantages of FMCW Radar 26

‎2.3 Summaru of The Related Works 36

‎3.1 Estimated Target RCS 40

‎3.2 FMCW Radar Specifications 47

‎3.3 Bill of Materials 47

‎3.4 Target Velocity Determination 51

‎4.1 Link Budget Analysis for Each Component 64

‎4.2 Link Budget Analysis of Complete Transmiter System 64

‎4.3 Signal Output Power at Critical Nodes 67

‎4.4 Target Velocity Identifications 71

‎5.1 Noise Figure and Gain of Recceiver Components 78

‎5.2 Measured Speed and Observed Speed of a Moving Target at

Maximum Distance of 4 Meters 81

‎5.3 Measured Speed and Observed Speed of a Moving Target at

Maximum Distance of 16 Meters 83

‎5.4 Summary of Measured Speed and Percentage Error 87

xi

LIST OF FIGURES

Figure No. Page No.

1.1 Research Methodology Flow Chart 7

2.1 Radar Receiver Output Signal and Interference 12

2.2(a) Radar Range Resolution: Range of Target From Radar 13

2.2(b) Radar Range Resolution in Time Intervals 13

2.3 Radiation Pattern of Directional Antenna 15

2.4 Cw Doppler Radar 17

2.5 Transmit And Receiver Signal Frequency 17

2.6 Fmcw Radar Basic Block Diagram with Two Antennas 19

2.7 Linear Saw-Tooth Ramp 20

2.8 Modulation Pattern for FMCW Radar 21

2.9 Triangle Modulation Pattern 22

2.10 Phased Array With A Target At An Angle Of 𝜃 29

2.11 Deployed FMCW Phased Array Radar at Avalanche Site 30

2.12 Block Diagram of the FMCW Phased Array Radar 31

2.13 MIMO Radar 32

2.14 MIMO Radar Block Diagram 32

2.15 Radar imaged by the FMCW MIMO Radar 33

2.16 Satellite View of Radar Coverage 33

2.17 Mounted FMCW SAR Device on a 1.5m Rail 35

2.18 Embedded SAR Processor 35

3.1 Antenna Design 38

3.2(a) Slow Moving Targets: Train Toys 39

xii

3.2(b) Slow Moving Targets: Human Body =1 m2 39

3.2(c) Slow Moving Targets: Human Body + Flat-plate Aluminium Foil 40

3.3 Radar Computer Based System 41

3.3 Raw Data of Maximum Target Range 13.735meters in Discrete Domain 42

3.5 Beat Signal in Time Domain 43

3.6 MTI Cancellor Operation 44

3.7 Beat Signal 44

3.8 Beat Signal in Frequency Domain 45

3.9 FMCW Radar Hardware Architecture 46

3.10 Experimental Test Site 50

4.1 FMCW Chirp Design and Its Parameters 52

4.2 Triangular Waveform Generation 54

4.3(a) 2.4GHz FMCW Radar Oscillator in Time Domain 54

4.3(b) 2.4GHz FMCW Radar Oscillator in Frequency Domain 54

4.4(a) Frequency Modulated Waveform 55

4.4(b) Zoomed Frequency Modulated at 40ms 55

4.4(c) Zoomed Frequency Modulated at 80ms 55

4.5 VCO Spectrum 56

4.6 Schematic Diagram of a Power Amplifier 58

4.7(a) Ideal Parameters for Power Amplifier, Estimated Input Power=3dBm 60

4.7(b) Ideal Parameters for Power Amplifier, S21 or Gain =13.638db 60

4.7(c) Ideal parameters for Power Amplifier, S12=-27.316dB 60

4.7(d) Ideal parameters for Power Amplifier, S22=-2.677dB 60

4.8 Amplifier Stability Analysis 61

xiii

4.9 Transmitter FMCW Radar System Design 62

4.10(a) Power Spectrum of Transmit Signal by Using Envelope Analysis 63

4.10(b) Power Spectrum of Transmit Signal by using Harmonic Balance

Analysis 63

4.11 New Model of Two-Way Power Splitter 64

4.12 A Complete Design of a FMCW Radar System 65

4.13(a) Receive Power Spectrum without Low Pass Filter 68

4.13(b) Receive Power Spectrum with Low Pass Filter 68

4.14(a)Velocity Measurements with Four Different Target Motion for Very Slow

Speed 70

4.14(b)Velocity Measurements with Four Different Target Motion for Slow

Speed 70

4.14(c) Velocity Measurements with Four Different Target Motion for Fast

Speed 70

4.14(d) Velocity Measurements with Four Different Target Motion for Very Fast

Speed 71

5.1 FMCW Radar Block Diagram 73

5.2 Linear Triangular Waveform Generation 74

5.3 Transmitter Spectrum 75

5.4 Measured Power Amplifier Output Power 76

5.5 Radar Transmit Power 77

5.6 Velocity Measurement of a Moving Train 80

5.7 Human Moves in Three Scenarios at 4meters Maximum Range. 81

5.8 Human Moves in Three Scenarios at 16 Meters Maximum Range 84

5.9 Speed Target Measurement of Human Movement 86

5.10 Speed Target Measurement of Human Movement While Carrying

Aluminium Box 86

5.11 Human Movement While Carrying Aluminium Box 87

xiv

5.12 Target Range Measurement without Pulse Cancellor 89

5.13 Higher Target Reflectivity 89

5.14 Target Range Measurement with MTI Pulse Cancellor 90

xv

LIST OF ABBREVIATIONS

2D 2-dimensional

3D 3-dimentional

ADS Advanced Design System

ADC Analog to Digital Converter

CW Continuous Wave

DAQ Data Acquisition

DDS Data Display

DDS Direct Digital Synthesis

EDA Electronic Design Automation

FFT Fast Fourier Transform

FM Frequency Modulated

FMCW Frequency Modulated Continuous Wave

FSK Frequency Shift Keying

GB- SAR Ground Based Synthetic Aperture Radar

HPBW Half Power Beam Width

IDFT Inverse Discrete Fast Fourier Transform

IEEE Institute of Electrical and Electronics Engineers

ITU International Telecommunication Union

LFM Linear Frequency Modulated

LOS Line-of-Sight

LNA Low Noise Amplifier

MCMC Malaysian Communications and Multimedia

Commission

MDS Minimum Detectable Signal

MTI Moving Target Indication

MIMO Multiple Input Multiple Output

NF Noise Figure

PCB Printed Circuit Board

RADAR Radio Detection and Ranging

RCS Radar Cross Section

RF Radio Frequency

SAW Surface Acoustic Wave

SISO Single Input Single Output

SNR Signal to Noise Ratio

UHF Ultra High Frequency

VCO Voltage Control Oscillator

WAV Waveform Audio

xvi

LIST OF SYMBOLS

𝑃𝑡 Peak transmit power

G Antenna gain

𝜆 Operating signal wavelength

𝜎 Radar cross section

𝑆𝑚𝑖𝑛 Minimum detectable signal

𝜏 Pulse width

𝐶0 Constant speed of light

∆𝑟 Range resolution

𝜎0 Backscatter coefficient

𝜕𝐴 Area of interception

𝐴𝑒 Effective aperture

𝜌𝑎 Antenna aperture efficiency

𝐴 Antenna physical area

𝜃 Beam width

D Antenna diameter

𝑓0 Centre frequency

𝑉𝑟 Radial velocity

𝑓𝑑 Doppler frequency

𝑎𝑡 Instantaneous transmitter signal

𝛼 Transmit signal chirp rate

𝑏0 Amplitude receive signal

𝑆𝐼𝐹 Beat signal

R Target range

B Bandwidth

𝑓+ Up chirp

𝑓− Down chirp

K Boltzmann constant

T0 Room temperature 290K

Bn Noise receiver

Fn Receiver noise factor

∆𝑡 Time difference between transmit and receive signal

N Number of samples per pulse

X(k) Receive signal in digital domain

k Stability factor

∆ Delta

𝜈𝑞 ADC noise floor

𝑉𝑝−𝑝 Peak to peak voltage

𝑃𝑟𝑚𝑖𝑛 Minimum receive power

S21 Forward gain

S22 Reverse reflection coefficient

S11 Forward transmission coefficient

S12 Reverse gain

1

CHAPTER ONE

INTRODUCTION

1.1 OVERVIEW

Remote sensing is an approach of accomplishing information of a target or

phenomenon using assembled electronic devices from distance or wirelessly. Remote

sensor technology has an enormously huge area of applicability such as in military,

geology, medical, agronomy and forestry. It is best implemented for any situation in

which direct measurements are not possible and long range applications, for instance;

satellite communication, natural disaster monitoring and airplane traffic controlling.

The technology is categorized into two types; passive and active remote sensing

system.

Passive remote sensor measures energy which is available naturally, sunlight is

a regular source of radiation measured by the sensor. Examples of the sensors are

including film photography, infrared, charge-couple devices and radiometers

(“Remote Sensing,” n.d.). On the other hand, an active remote sensor generates and

emits its own source of energy towards a target and measures backscattered energy

from the target. Hence, information of the required target is obtained by measuring

and analyzing the backscattered energy. In other words, the active remote sensor is a

two-way operation while the passive remote sensor is a one-way operation. One main

advantage of the active remote sensors is that the emitted radiation can be

preconditioned by the user to highlight the target object in a certain way.

Radio Detection and Ranging (RADAR) is a well-known example of active

remote sensor applications which is mostly used by researchers and engineers these

days. Basically, radar technology transmits microwave signal into space until hits

2

target and some portion of return radiation from a reflected target is collected by using

receiver antenna. A signal processing technique is implemented to measure and

analyze the collected raw data of the return signal to be able to earn information of

required object. Over the past century, conventional radar is only used for detecting

and allocating a target. However, thanks to an evolution and development of the radar

technology, modern radars are produced as well as extending the capability of the

radars, such as accurate targeting, target identification and classification, navigation,

guidance, imaging and etc. (Kassatokis, 2014).

The radar system is generally operating at microwave frequency range of

300MHz until 300GHz. Since it generates and emits a short wavelength of

electromagnetic signals, its operation is unaffected by all types of weather and light

conditions such as darkness, rain, snow, fog, smoke and dust during transmitting

signal into space. In addition, radar is best used for long range applications as the

radiation travels with the speed of light in space. Hence, it is an efficient tool for

scientific measurement.

Frequency Modulated Continuous Wave (FMCW) radar is widely used for

safety applications since decades ago. They are including hazards; snow avalanche

monitoring(M Ash, Brennan, Vriend, Mcelwaine, & Keylock, 2011) and landslide

monitoring (Luo et al., 2014), road safety; pedestrian detection (Ariel Etinger et al.,

2014) and vehicle collision mitigation (Roggero, Zhao, & Zucchelli, 2015).

Nowadays, users or authorities are eager for sophisticated radars which can provide

good sensitivity for the particular applications. A radar device is classified as

possessing good sensitivity when it is able to detect and measure a target in worst

conditions. For example, a small target which moves at very low speed with a lot of

interferences’ existence.

3

The target in such condition produces weak backscattered signal in which

normally neglected by conventional radar due to high sensitivity requirement of the

hardware which consequently increased the incur development cost. However, the

neglected signal could cause a massive effect such as loss of lives due to road crashes.

According to (A Etinger et al., 2014), more than 3000 people around the world lose

their lives every day due to the particular reason where half of the victims are

pedestrians who are exposed road users. Hence, a radar remote sensor that is sensitive

enough to detect the aforementioned slow moving target is needed to reduce the

severity of damages.

Meanwhile, the selection of equipment and techniques are among the crucial

factors that affect the capability of the detector as well as its cost of fabrication. For

that reason, many researchers and industries have contributed ideas, innovations and

improvements for its betterment. Numerous great radar projects were done for the

slow moving target studies. However, they provide good sensitive radar remote

sensors by implementing sophisticated approaches such as advanced electronic tools

and techniques due to big budget possessing and many technical experts were

involved.

Therefore, this research has explored processing technique of Doppler

principle in an inexpensive FMCW radar system design for detection of weak

backscattered signal while providing comparable sensitivity as the previous work. At

the Microwave Laboratory of International Islamic University Malaysia, various

experiments were conducted to investigate its reliability to detect slow moving target

as well as to accurately measure the range and velocity of the slow moving target. It is

expected that the outcome of this research can be implemented into vehicle safety

applications for moving pedestrian detection and monitoring. It is also hoped that the

4

implementation of the output of this research project can assist Malaysian authorities

such as Malaysian Automotive Association to take appropriate actions in order to

reduce the losses and damages.

1.2 STATEMENT OF THE PROBLEM

Previous work had been conducted in London whereby FMCW radar system with

phase array technique were implemented for slow moving target applications. (M Ash

et al., 2011). It claimed that the target minimum speed that can be determined

accurately by the radar system was 5.7m/s. One of the main factors effected the

minimum speed determination is the radar sensitivity. Since the radar has complicated

circuitry design at the receiver system, it provides a lot of noise and subsequently

reduce the radar sensitivity performance.

According to (A Etinger et al., 2014), pedestrian movement can be very slow,

approximately speed of 0.5m/s. Radar system with higher sensitivity should be

suggested. Therefore, this research develops a low cost FMCW radar system with

deramping process to improve the previous radar’s sensitivity so that it capable to

detect and determine the speed and range of the slow moving target.

5

1.3 RESEARCH OBJECTIVES

The objectives of this research are as the followings:

i. To develop a low cost S-band FMCW radar system with radar’s sensitivity

improvement for slow moving target applications (i.e: pedestrian detection)

ii. To determine the speed and range of the pedestrian using Doppler principle.

iii. To investigate the performance of the FMCW radar with different type of

speeds, ranges and targets.

1.4 RESEARCH METHODOLOGY

The methodology of this research consists of the following activities:

i. Preliminary investigation

This research starts with understandings of some basic principle of the

conventional radar system and how it is working. Reflectivity of a target and receive

signal detection level are also reviewed. In addition, FMCW radar basic block

diagram will be introduced along with its superior advantages for moving target

applications. Numerous studies on previous related works will be outlined while

identifying their implemented parameters and methods for the radar system.

ii. Approaches and parameters analysis

The relevant approaches of radar’s design determine its performance outputs.

There are several main approaches that will be taken close attention during the design

process. They are including operating frequency, waveform modulation, antenna,

target, Data Acquisition (DAQ) system and simulation computational software. These

approaches will be selected based on their cost-effectiveness, sensitivity and reliability

to detect slow moving target.

6

iii. Simulation analysis

Preliminary design of FMCW radar system is tested using Agilent Advanced

Design System (ADS) version 2014. It is compatible for RF and microwave

applications. Several simulators are provided by the software such as Envelope,

Harmonic Balance, Scattering Parameters and also Budget analysis. By utilizing the

software, any flaws and radar’s breakthrough is detected, hence finalized radar system

with optimized performance is successfully designed.

iv. Design decision analysis

The proposed FMCW radar system consists of four main parts. They are

including transmitter, receiver, antenna, and DAQ system. Each part contains several

assembled electronic components.

v. Purchase and assemble electronic components

The proposed components are purchased from multiple manufacturers

according to their availability in stock. RF components such as Voltage Controlled

Oscillator (VCO), amplifier, mixer and splitter are bought from Mini-Circuits while

other components are from Farnell14 element and eBay. After that, they are

assembled and fabricated an FMCW radar hardware.

vi. Experimental test analysis

Various experiments are carried out to investigate the capability of the radar to

detect and measure the range and velocity of a slow moving target. Different types of

targets, distances and speeds are applied during the analysis. The activities are held in

a Microwave Laboratory. The collected raw data is analysed in MATLAB 2013a with

Moving Target Indication (MTI) algorithm for range measurement while Doppler

principle for speed measurement. Based on the conducted experiments, the

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performance evaluations of the radar for the particular goals are achieved and

subsequently concluded with percentage error.

Flow chart of the research methodology is summarized as in Figure 1.1:

Figure 1.1: Research methodology flow chart

1.5 RESEARCH SCOPE

Radar system for detection and measurement is an extensive topic. There are various

radar system that can be used for the specific purpose such as pulse radar, Continuous

Wave (CW) radar and Frequency Modulated Continuous Wave (FMCW) radar.

However, this thesis covers FMCW radar only. Besides, this project focused on the

elements which effected the radar sensitivity performance. In addition, this research

dedicates specific digital signal processing technique for clutter rejection, Moving

Target Indication. Other common digital signal processors such as range processing,

azimuth processing, array and location calibrations are not covered in this thesis. The

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analyses are validated by conducting real time experimental activities in indoor area,

outdoor experiments are out of scope. The radar system examined human movement

in which its Radar Cross Section is estimated to 1 (Skolnik, 2001). However, micro

Doppler effect due to human moving of hands or legs is not covered in this thesis.

1.6 THESIS ORGANIZATION

This thesis is arranged into six parts. Chapter 1 outlines overview about radar system

background and its general principle. It also includes research problem statements

and its significant, research objectives, research scope, research methodology, and

research layout.

Second chapter describes background theory in this research field which

consists of basic radar theory and FMCW radar principle together with its advantages

and disadvantages. Another focus of this Chapter 2 is the Doppler principle along

with signal processing for slow moving target detection. Literature surveys of

previous related works are also included.

Third chapter comprises detail explanations on step by step procedures to

accomplish the radar system design. Among them, radar considerations and selected

methods are included. Furthermore, FMCW radar hardware is fabricated and its bill of

materials is listed.

Fourth chapter presents the simulation analyses of radar system by using

Agilent Advanced Design System (ADS) version 2014. Oscillation, scattering

parameters and link budget analysis are provided. This chapter also provides the

performance analyses of designed radar system to detect moving target by using

Doppler principle.