UNIVERSITI TEKNOLOGI MALAYSIA
BORANG PENGESAHAN STATUS TESIS?
JUDUL: VOICE COMMUNICATION USING RF SESI PENGAJIAN: 2007/2008
MOHD SAIFUL EFFENDI BIN MUSTAPA ALBAKRI
mengaku membenarkan tesis (PSM/Sarjana/Doktor Falsafah)* ini disimpan di Perpustakaan Universiti Teknologi Malaysia dengan syarat-syarat kegunaan seperti berikut: 1. Tesis adalah hakmilik Universiti Teknologi Malaysia. 2. Perpustakaan Universiti Teknologi Malaysia dibenarkan membuat salinan untuk tujuan pengajian sahaja. 3. Perpustakaan dibenarkan membuat salinan tesis 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) (Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasi/badan di mana penyelidikan dijalankan)
________________________________ (TANDATANGAN PENULIS)
Alamat Tetap: 27, JALAN CEMPAKA 29,
________________________________ (TANDATANGAN PENYELIA) EN. CAMALLIL BIN OMAR (Nama Penyelia)
TAMAN CEMPAKA, 68000 AMPANG, SELANGOR
Tarikh : 30 NOVEMBER 2007
: 30 NOVEMBER 2007
Jika tesis ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/organisasi berkenaan dengan menyatakan sekali sebab dan tempoh tesis ini perlu dikelaskan sebagai SULIT atau TERHAD.
Potong yang tidak berkenaan.
Tesis dimaksudkan sebagai tesis bagi Ijazah Doktor Falsafah dan Sarjana secara penyelidikan, atau disertasi bagi pengajian secara kerja kursus dan penyelidikan, atau Laporan Projek Sarjana Muda (PSM).
"I declare that I have assessed this thesis and in my opinion, it is suitable in terms of scope and quality for the purpose of awarding a Bachelor Degree in Electrical Engineering (Electronics)”.
Signature Supervisor Name Date
: ……………………………….. : EN CAMALLIL BIN OMAR : 30 NOVEMBER 2007
VOICE COMMUNICATION USING RF
MOHD SAIFUL EFFENDI BIN MUSTAPA ALBAKRI
This thesis is submitted as a part of fulfillment the requirements for the degree of bachelor of Electrical Engineering (Electronic)
Faculty of Electrical Engineering Universiti Teknologi Malaysia
"I declare that this thesis entitled “Voice Communication Using RF” is the result of my own research except as cited in the references. The thesis has not been accepted for any degree and is not concurrently submitted in candidature of any other degree ”
Signature Author Date
: ……………………………........................... : MOHD SAIFUL EFFENDI BIN MUSTAPA ALBAKRI : 30 NOVEMBER 2007
Specially dedicated to My beloved parents, brothers and sisters who have encouraged, guide and inspired me throughout my journey in education
Praise be to Allah S.W.T the Most Gracious, the Most Merciful, whose blessing and guidance have helped me through my thesis smoothly. Peace and blessing of Allah be upon our Prophet Muhammad S.A.W who has given guidance to mankind.
I would like to take this opportunity to express my deepest gratitude to my beloved supervisor of this project, Mr. Camallil Bin Omar who has relentlessly and tirelessly assisted me in completing this project. He has given me support and insight in doing this project and has patiently listened and guided. My thanks also go to my family who has given me support throughout my academic years.
I also would like to express my gratitude to my friends for their co-operation during doing this project. I also wish acknowledgement to the people who give support directly or indirectly to the project. Once again, thank you very much.
The aim of the project is to develop a miniaturized low power FM transmitter and FM receiver that can be used as equipment for helping in the communication system such as room monitoring. The overall module should be miniature to enable portability. By using the wireless microphone people can speak anywhere instead of speaking in one place. Frequency modulation (FM) has several advantages over the system of amplitude modulation (AM) used in the alternate form of radio broadcasting. The most important of these advantages is that FM system has a greater freedom from interference and static. A well-design FM receiver is not sensitive to such disturbances when it is tuned to an FM signal of sufficient strength. Also, the signal-to-noise ratio in an FM system is much higher than that of an AM system. FM broadcasting stations can be operated in the very high frequency bands at which AM interference is frequently severe; commercial FM radio stations are assigned frequencies between 88 MHz to 108 MHz and will be the intended frequency range of transmission. The objectives of this project is to use as a communication equipment where when the signal (voice) captures by the FM transmitter and transmit through the receiver by tuning the frequency in the range of FM frequency which not being used by other radio station.
Matlamat projek ini adalah bertujuan untuk membina alat pemancar FM berkuasa rendah dan penerima FM(radio) yang boleh digunakan sebagai alat yang boleh membantu di dalam sistem komunikasi. Secara keseluruhan, modul ini akan dibina sebagai alat yang mudahalih iaitu mudah diubah kedudukannya. Dengan menggunakan mikrofon tanpa wayar, pengguna boleh bercakap di mana-mana sahaja di dalam satu tempat. Terdapat beberapa kelebihan dalam sistem FM berbanding AM iaitu FM banyak digunakan di dalam penyiaran radio. FM juga mempunyai kebebasan dalam gangguan hingar serta statik. Nisbah hingar FM juga lebih tinggi berbanding AM di mana gangguan hingar AM lebih tinggi. Siaran stesen radio FM adalah dari 88Mhz sehingga 108Mhz dan ini akan dijadikan sebagai frekuensi pancaran. Objektif projek ini adalah sebagai alat komunikasi dimana apabila isyarat suara berjaya diterima oleh alat pemancar FM dan dipancar kepada penerima tersebut ditala frekuensinya dalam lingkungan frekuensi FM iaitu 88Mhz sehingga 108Mhz dan boleh digunakan oleh mana-mana stesen radio.
TABLE OF CONTENT
TITLE DECLARATION DEDICATION ACKNOWLEDGEMENT ABSTRACT ABSTRAK TABLE OF CONTENT LIST OF FIGURES LIST OF TABLES LIST OF ABBREVIATION LIST OF APENDICES
i ii iii iv v vi vii xi xii xiii xv
INTRODUCTION 1.1 1.2 1.3 1.4 Review Objectives Scope of project Outline of the thesis 1 2 2 3
LITERATURE REVIEW 2.1 2.2 Background Communications theory 2.2.1 2.2.3 Transmitter Noise 2.2.2 Receiver 4 5 6 6 7
viii 2.3 Modulation 2.3.1 2.3.3 2.4 2.5 2.6 Description of modulation Frequency modulation 2.3.2 Need for modulation 2.3.4 Derivation of FM equation Demodulation 2.4.1 Phase Lock Loop (PLL) Power amplifier The resonant circuit 2.6.1 Parallel resonant circuit 7 7 8 9 13 14 14 16 18 18
METHODOLOGY 3.1 3.2 Low Power FM Transmitter Discrete components 3.2.1 3.2.3 3.2.4 3.3 3.3.1 3.3.2 3.3.3 3.3.4 3.4 3.4.1 3.4.2 3.5 3.6 Electret microphone Inductor Resistor Class A Class AB Class B Class C One transistor design Two transistor design 3.2.2 Capacitor 19 20 20 21 22 24 25 26 27 28 29 30 30 31 32 33 33 34 35 37 38
Design under consideration
Final layout design FM Receiver 3.6.1 Introduction 3.6.2 3.6.3 3.6.5 Theory Noise in FM receiver FM receiver circuit
3.6.4 Design FM receiver
ix 3.6.6 3.6.7 3.6.8 3.7 Description of FM receiver circuit Active IF filter Final layout design 39 41 42 42 43 44 45 45 47
Audio Amplifier 3.7.1 Introduction 3.7.2 3.7.3 3.7.4 Analysis of LM386 chip Additional gain High gain and filtering
RESULTS AND ANALYSIS 4.1 4.2 4.3 4.4 4.5 4.6 Analysis results Final FM transmitter circuit Final FM receiver circuit Final audio amplifier circuit Final hardware design Discussion 48 50 51 52 53 54
CONCLUSION AND RECOMMENDATION 5.1 5.2 5.3 Chapter overview Conclusion Recommendation for the future work 55 55 56
LIST OF FIGURE
FIGURE NO. 2.1 2.2 2.3 2.4 2.5 2.6 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17
TITLE Block diagram of communication system Block diagram for voice communication using RF Antenna calculation Frequency modulation spectrum Example waveform frequency modulation Block diagram of PLL Electret microphone Self-made equation Frequency calculation Class of power amplifier Class A voltage and current waveform Class A circuit diagram Load line of class A amplifier Class AB voltage and current waveform Class B voltage and current waveform Class C voltage and current waveform Class C circuit diagram Load line of class C amplifier One transistor design Two transistor design Final layout design he slot noise generator frequency plan The TDA7000 as a Variable Capacitor Tuned FM Broadcast Receiver
PAGE 5 6 10 11 13 15 20 23 23 25 26 26 27 28 28 29 29 29 30 31 32 36 38
xi 3.18 3.19 3.20 3.21 3.22 3.23 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.11 IF filter of the TDA7000 Measured response of the IF filter FM receiver circuit LM386 schematic Audio amplifier circuit Voltage gain Graph supply current vs voltage Power output vs supply voltage Final FM transmitter circuit Waveform from transmitter when no speaking Final FM receiver circuit PCB layout for FM receiver Audio amplifier circuit PCB layout for audio amplifier Final hardware design for voice Communication using RF FM receiver hardware FM Transmitter hardware 53 53 53 41 42 42 44 46 46 49 49 50 50 51 51 52 52
LIST OF TABLES
TABLE NO. 3.1 3.2 3.3 4.1
TITLE Gives a standard overview of the types of resistors used and their specification Comparison of peak possible efficiency for different operation classes of power amplifiers. Mixer slot noise level Supply current and output current
24 26 34 48
LIST OF ABBREVIATIONS
RF MHz PA Fc I R Z C L Fo Q FM AM PM N L A β
Radio Frequency Megahertz Power Amplifier Frequency Carrier Current Resistance Impedance Capacitor Inductor Resonant frequency Quality factor Frequency modulation Amplitude modulation Phase modulation Number of turns in coil Length of coil Cross sectional area of coil Current gain
LIST OF APPENDICES
APPENDIX A B
TITLE Datasheet TDA7000 Datasheet LM386
PAGE 58 59
Frequency modulation (FM) is the method of varying a carry wave’s frequency proportionally to the frequency of the other signal especially in the case of the human voice. If we compared to the other transmission method like amplitude modulation (AM) vary the amplitude of the carrier wave according to an input signal. Frequency modulation (FM) has several advantages over the system of amplitude modulation (AM) used in the alternate form of radio broadcasting. The most important of these advantages is that an FM system has greater freedom from interference and static. FM broadcasting stations can be operated in the very high frequency bands at which AM interference is frequently severe; commercial FM radio stations are assigned frequencies between 88Mhz to 108Mhz and will be the intended frequency range of transmission. In this project we will discuss upon the usage of frequency modulation (FM) where this method brings many advantages compared to other method. In this project also, we will discuss how FM receiver can be build from one chip and can hear the radio from other frequency using this method.
2 1.2 Objectives
This project has a number of main objectives. They are: ? ? ? ? To design and build low power transmitter over the FM frequency and allows the transfer of the voice over the certain distance to a FM tuner To design and build FM receiver so that voice from transmitter can be heard when we tuned the frequency. To facilitate the user that they can speak without any wiring interference in the certain distance. To learn, understand and gain new knowledge about FM transmitter and FM receiver.
Scope of project
The scopes of this project are listed below: 1) Study about the theory to develop this system: ? ? ? ? ? Principle communication Frequency modulation (FM) Radio frequency Wireless communication The components that being used for this project
2) Design the suitable circuit that can apply to achieve the objective. ? ? ? ? ? Electrets microphone Small signal amplifier Power amplifier FM receiver Audio amplifier
3 1.4 Outline of the thesis
This thesis is organized into 7 chapters, leading through fundamental of FM transmitter. This thesis will also concentrate on the theory and procedure in designing FM transmitter, receiver and audio amplifier. Chapter 1 gives the brief introduction on frequency modulation as well as the application of the FM transmitter.
In chapter 2, the introduction briefly describes the frequency modulation theory, the advantages of the FM and the derivation of the FM voltage equation. It also explain on the technical terms that associated in the FM and also explaining briefly on the capture effect and the modulation effect or the modulation factor of FM and also the FM demodulation.
In chapter 3, we discuss more about the low power FM transmitter, FM receiver and audio amplifier. In this chapter also, the theory that briefly described of this three part included. The design procedure and design specification are presented in this chapter. The final layout for transmitter, receiver and audio amplifier will also present in this chapter.
Chapter 4 deals with the results and analysis obtained from the experiments. In chapter 5 devoted to a conclusion of the project. Recommendation for future implementation also presented.