Direct Conversion 700 MHz RF Transmitter.
i
DIRECT CONVERSION 700 MHZ RF TRANSMITTER
MUHAMMAD NADZREEN MOHD NOOR
This Report Is Submitted In Partial Fulfillment of Requirement for the Bachelor of Electronic Engineering (Telecommunication Electronic)
Faculty of Electronic and Computer Engineering UniversitiTeknikal Malaysia Melaka
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UNIVERSTI TEKNIKAL MALAYSIA MELAKA
FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER BORANG PENGESAHAN STATUS LAPORAN
PROJEK SARJANA MUDA II
Tajuk Projek : DIRECT CONVERSION 700 MHZ RF TRANSMITTER Sesi
Pengajian : 1 0 / 1 1
Saya MUHAMMAD NADZREEN MOHD NOOR
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)
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“I hereby declare that this report is result of my own effort except for quotes as cited in the references.”
Signature : ……….
Name : MUHAMMAD NADZREEN MOHD NOOR
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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 Electronic).”
Signature : ……….
Supervisor’s Name : PROF. MADYA ABD RANI BIN OTHMAN
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To my dearest parent,
Mohd Noor Abu Bakar and Zaharah Ismail, my friends,
who have always sincerely pray for my success and glory.
To my Supervisor, Prof. Madya Abd Rani Othman
and my co-supervisor, Dr. Zulkarnain Mohd Yusof. Thank you for your help and taught.
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ACKNOWLEDGEMENT
In the name of Allah S.W.T., The Most Beneficial and The Most Merciful. It is with deepest serve gratitude of the Al-Mighty that gives me strength and capability to complete this final year project thesis.
The special thank goes to my helpful supervisor, Prof. Madya Abd Rani Othman. The supervision and support that he gave truly help the progression and smoothness of this thesis writing. The co-operation is much indeed appreciated.
My grateful thanks also go to my co-supervisor, Dr. Zulkarnain Mohd Yusof, from TM R&D. A big contribution and hard worked from him during the process is very great indeed. Besides, this project makes me realized the value of hardworking. Not forget, great appreciation go to the rest of TM R&D’s staff that help me from time to time during the project.
Great deals appreciated go to the contribution of my faculty - Faculty of Electronic Engineering and Computer Engineering. Last but not least, I would like to thank my friends especially those who study together as student at University Technical Malaysia Malacca as their help throughout completing this project thesis.
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ABSTRACT
This project presents the Direct Conversion 700 MHz RF Transmitter which was designed to produce transmitted output power of 22 dBm. The design of this 700 MHz RF transmitter consist of five section altogether. First section is 25 MHz high pass filter, followed by 35 MHz low pass filter. A 700 MHz Mixer, Gain Block, and Power Amplifier complete the design. All component and circuit involved in this design are based on manufacturer`s recommended application circuit. The software used when designing the modules are Cadence OrCAD tools and Advance Design System 2008 (ADS2008). The direct conversion transmitter produces gain of 22 dBm and bandwidth of 30 MHz.
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ABSTRAK
Projek ini menerangkan tentang penghantar isyarat penukaran terus frekuensi radio pada 700 MHz yang telah dihasilkan untuk mengeluarkan kuasa hantaran sebanyak 22 dBm. Penghantar isyarat ini direkabentuk daripada lima bahagian. Bahagian pertama adalah penapis isyarat tinggi 25 MHz, diikuti oleh penapis isyarat rendah 35 MHz. Pencampur frekuensi 700 MHz, blok peningkat, dan penguat kuasa juga melengkapkan lagi modul ini. Semua bahagian dan litar yang terlibat dalam rekabentuk isyarat ini pada dasarnya telah dicadangkan oleh pengeluar. Alatan rekaan bantuan komputer seperti Cadence OrCAD dan perancangan sistem termaju 2008 (ADS2008) daripada Teknologi Agilent digunakan bagi membantu proses merekabentuk setiap modul di dalam penghantar isyarat ini. Penghantar isyarat ini menghasilkan keluaran 22 dBm dan lebar jalur 30 MHz.
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TABLE OF CONTENTS
CHAPTER TITLE PAGE
PROJECT TITLE i
STATUS REPORT CONFIRMATION FORM ii
APPROVAL SHEET iii
DECLARATION SHEET iv
DEDICATION v
ACKNOWLEDGEMENT vi
ABSTRACT vii
ABSTRAK viii
TABLE OF CONTENTS ix
LIST OF FIGURES xiii
LIST OF TABLE xv
I
1.1
INTRODUCTION
BACKGROUND 1
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1.3 SCOPE OF WORK 3
1.4 PROJECT ACTIVITY 3
1.5 ORGANIZATION OF THE REPORT 4
1.6 COMPANY BACKGROUND 5
II LITERATURE RIVIEW
2.1 INTRODUCTION 6
2.2 RADIO FREQUENCY 6
2.3 PARAMETER 7
2.4 BANDWIDTH 9
2.5 TRANSMITTER 10
2.6 TRANSMITTER ARCHITECTURE 11
2.6.1 Direct Conversion Transmitter 12
2.6.2 Two Step (Dual) Conversion Transmitter 13 2.6.2.1 Conventional Technique 13 2.6.2.2 Quadrature Modulator 14
2.7 TRANSMITTER MODULE 15
2.7.1 Filter 15
2.7.2 Mixer 17
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2.8 PATH LOSS 20
2.9 ATTENUATOR 21
2.10 CONCLUSION 22
III METHODOLOGY
3.1 INTRODUCTION 23
3.2 RESEARCH METHODOLOGY 23
3.3 RF TRANSMITTER LINK BUDGET 25
3.4 RF TRANSMITTER OPERATION 26
3.5 FILTER DESIGN 27
3.5.1 25MHz High Pass Filter 27
3.5.2 35MHz Low Pass Filter 28
3.6 PCB BOARD DESIGN 29
3.7 BLOCK DIAGRAM OF 700MHz RF TRANSMITTER 30
3.8 CONCLUSION 31
IV RESULT AND ANALYSIS
4.1 INTRODUCTION 32
4.2 RESULT 33
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4.2.2 35MHz 11th Order Low Pass Filter 35
4.3 SUPPLY CURRENT 37
4.4 OVERALL RESULT OF TRANSMITTER MODULE 38
4.5 TRANSMITTING DISTANCE 39
4.6 CONCLUSION 40
V CONCLUSION
5.1 INTRODUCTION 41
5.2 CONCLUSION 41
5.3 RECOMMENDATION FOR FUTURE PROJECT 42
REFERENCES 43
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LIST OF FIGURES
FIGURE TITLE PAGE
2.1 Bandwidth of 30 MHz 10
2.2 Typical transmitter block diagram 11
2.3 Typical transmitter architecture 12
2.4 Direct-conversion transmitter 13
2.5 Two-step transmitter architecture 14
2.6 Quadrature modulator block diagram 15
2.7 Chebychev filter return loss 16
2.8 Low pass filter 16
2.9 High pass filter 16
2.10 SAW filter internal structure 17
2.11 Frequency mixer symbol 18
2.12 Signal input and output of an up-conversion mixer 18
2.13 Class A single ended power amplifier 19
2.14 Path loss of communication system 21
2.15 Π attenuator 21
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3.1 Flowchart of methodology 24
3.2 Direct conversion 700 MHz RF transmitter architecture by ADS2008
26
3.3 7th order 25 MHz High Pass Filter 28
3.4 711th order 35 MHz Low Pass Filter 28
3.5 Expected hardware of Direct Conversion 700 MHz RF Transmitter
30 3.6 Prototype of the direct conversion 700 MHz RF Transmitter 30
4.1 Measurement process 33
4.2 Plotted of S21 vs. Frequency of High Pass Filter 34
4.3 Plotted of S21 vs. Frequency of Low Pass Filter 36
4.4 Overall measurement process 37
4.5 Measurement result by Tektronik RSA at the end of the module 39 4.6 Measurement result by Spectrum Analyzer at the end of the
module
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LIST OF TABLES
FIGURE TITLE PAGE
2.1 S-Parameter properties of 2 port network 9
3.1 Gain of 700 MHz RF transmitter 25
4.1 Measurement value of 25MHz 7th Order High Pass Filter 34
4.2 Loss of 25 MHz 7th Order High Pass Filter 35
4.3 Measurement value of 35 MHz 11th Order Low Pass Filter 35
4.4 Loss of 35 MHz 11th Order Low Pass Filter 36
4.5 Comparison of supplied current 37
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LIST OF APPENDICES
APPENDIX TITLE PAGE
A High Pass Filter and Low Pass Filter 45
B Gain Block 46
C Mixer and SAW Filter 47
D Gain Block and Power Amplifier 48
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CHAPTER I:
INTRODUCTION
1.1 Background
Nowadays, the communications environment, especially in urban areas is often called hostile because it imposes severe constraints to the transceiver design. Wireless communications systems are greatly expected to play a major role in providing access to future information services. Complexity, power dissipation, cost and the numbers of external components have been the primary criteria in selecting and determining the transceiver architecture itself[1].
As integrated circuit (IC) technologies evolved, the importance of these criteria changes allowing the approaches that once seemed impractical to be used as a possible solutions. In the past, most wireless designs have been optimized for either high performance or energy-efficient operation.
The narrow bandwidth available to each user also impacts the design of the RF section. For example, the transmitter must employ narrowband modulation, amplification and filtering to avoid leakage to the adjacent channels
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while the receiver must be able to process the desired channel while strongly rejecting all neighboring interference signals [2]. In contrast to the variety of approaches invented in the RF receiver, transmitter architecture is found to be designed in a few forms. This is because the issue such as noise, interference rejection and the band selectivity are more relaxed in transmitters than in receivers.
A transmitter may create RF interfere with not only towards other wireless devices, but with many type of non-RF electronic equipment [3]. Harmonics and spurious output wideband and close-in noise, frequency and amplitude stability, and peak including average output powers, are but a few of the critical parameters that must be addressed before any transmitter design can be realized.
1.2 Objectives
i. To designs and develop the 700 MHz transmitter with maximum transmit output power of 25 dBm.
ii. To design and simulate 25 MHz Chebyshev high pass filter and 35 MHz Chebyshev low pass filter.
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1.3 Scope of work
Scope of work for this project is regarding to all of the objectives that have been stated. The most important thing for this project is to understand clearly about the transmitter system in radio frequency like the basic and standard operation of the system, the component that been used for the system and the advantages and disadvantages of the system. It also important to know the parameter and characteristic that will affect the APS system.
This project is to build a transmitter that transmits a 700MHz carrier signal. A direct-conversion approach is used in developing this RF transmitter. A signal bandwidth of 30MHz is inserted to the filter to leave only needed frequency signal. Then, an up conversion mixer is used to converts the signal into 700MHz RF carrier signal for transmitting. Power amplifier (PA) and Gain block provide gain to the system.
1.4 Project activity
The first need to know is to understanding the problem related with the final year project`s title that is this project of Direct Conversion 700MHz RF Transmitter. Then the understanding with literature review like survey and project management must be mastered before this project can be realized. The next step involved is in fabrication process. The PCB board layout must be design, assembly and tested precisely so it can work according to the specification. The final step involved is analyzing the result and conclude the finding if there are any.
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1.5 Organization of the Report
The structure of this project report was planned to provide a clear explanation about the project entirely. This thesis is divided into five chapters.
Chapter I introduces background, objectives, scope of work, project activity, and company background. In this chapter, some general knowledge about transmitting system will be presented. Due to the subsidizing from TM R&D for this project, there is some review on it.
Chapter II provides the literature review on the Transmitter system. It is about the process, the mechanism and the parameters that involved in the systems.
Chapter III describes in detail the methodology used during the project. There are 3 method that been used in this project which are calculation, simulation and measurement. In calculation part, the formula that been used to calculate in the system will be presented. But, the circuit for simulation part will be shown in chapter Four. For the measurement part, the measurement process will be introduced.
Chapter IV discuss about the result and the analysis. The result will have simulation and measurement data. The analysis and the comparison for the data will be included in this chapter.
Chapter V is about the conclusion for the project. The conclusion will be summarizing about the entire project. Recommendation for the project will also be included in this chapter.
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1.6 Company background
TM R&D, an entirely owned subsidiary of Telekom Malaysia Bhd. It starts its operation on 1st January 2001 as the R&D support of future business of TM. It also has the vision to grow to be a leading force technology company in the marketplace through research, development and innovation in Information and Communication Technology (ICT) industry.
R&D management is only one of its kinds due to the unpredictable market demand for state-of-art product and services. To remain responsive and competitive, TM R&D introduced several Knowledge Management initiatives as a frame-work to manage and utilize the wealth of intellectual capital inside the organization.
At TM R&D, they get on both basic together with applied research activities. It also has aligned research programs to sustain the strategic theme that covers different technological focused areas. The research activities conducted beneath division of basic research are mostly correlated to the development of nano and micro sized device for the purpose of electronic and photonic application. TM R&D also focus on it design simulation, fabrication technology development, and testing to meet up standard and quality contingent and system integration [4].
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CHAPTER II:
LITERATURE REVIEW
2.1 Introduction
This section explains about transmitter`s characteristic, parameters, transmitter architecture, and module of transmitter. Transmitter characteristic must me mastered out first before any designing can begin. In transmitter structure, there are many things and terms must be understood like transmit output power, gain, insertion loss, return loss, and other terms regarding this project.
2.1 Radio Frequency
Radio frequency (RF) was defined as a rate of oscillation in the range around 3 kHz to 300 GHz, which match to the frequency of radio waves, and the alternating currents that carries radio signals [5]. Here, RF generally refers to electrical rather than mechanical oscillations, although mechanical RF systems do exist.
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The electrical currents oscillating at radio frequencies have particular properties that differ from direct current or alternating current. Energy in RF current can radiate from a conductor into space as electromagnetic waves or radio waves. This is the foundation of radio technology. Instead of penetrating deeply into electrical conductors, RF current actually flows along their surfaces known as skin effect. As a result, whilst the human body comes in contact with high power RF currents it caused burns called RF burns. The current can simply ionize air, creating a conductive path through it. It also flows through paths that contain insulating material, like the dielectric insulator of a capacitor. When circuit are conducted by an ordinary electric cable, RF current has a tendency to reflect from discontinuities in the cable such as connectors and travel back down the cable toward the source and causing state named standing waves, so RF current have to be carried by particular types of cable called transmission line [6].
2.3 Parameter
S-parameters or scattering parameters best explain the electrical performance of linear electrical networks when endure various steady state caused by electrical signals in communication design. S-parameters characterize a linear electrical network by matched loads instead of open or short circuit conditions. These terminations are easier to implement at high signal frequencies and the quantities are measured in power (dB) [7].
Lots of electrical properties of components like inductors, capacitors, and resistors may be uttered using S-parameters, such as Gain, Voltage Standing Wave Ratio (VSWR), Return Loss, Reflection coefficient, and amplifier stability. In the circumstance of S-parameters, scattering refers when traveling currents and voltages in a transmission line are affected when they meet up a discontinuity caused by the insertion of a network into the transmission line.
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Even though appropriate at low or high frequency, S-parameters are mostly used for networks operating at radio frequency (RF) and microwave frequencies where energy considerations and signal power are easily quantified than currents and voltages [8].
Due to the theory of S-parameters that is changed by means of the measurement frequency, the frequency must be specified for any S-parameter measurements declared, in calculation to the characteristic or system impedance. S-parameters are generally represented in matrix form and comply with matrix algebra. By having two ports only in microwave network, that is an input and an output, the S-matrix has four S-parameters, designated like below:
S11 S12
S21 S22
These complexes quantities in fact contain eight divided numbers (real and imaginary parts), or modulus and phase angle, of each of the complex scattering parameters. If the output port 2 is terminated, the transmission line is connected to a matched load impedance and giving rise to none reflections, and produced no input wave on port 2. The input wave on port 1 gives rise to a reflected wave at S11. And a transmitted wave at port 2 which absorbed in termination on port 2. The transmitted wave dimension is S21. If the network used has none loss or gain, the output power must equal the input power and so in this case |S11|2 + |S21|2 is matched [9].
Therefore, the sizes of S11 and S21 determine the input power that splits between the potential output paths. Clearly, if 2-port microwave network represents a good amplifier, S11 needed are rather small and S21 are quite large. In general, the s-parameters stated much power comes back or out when the
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1.3 Scope of work
Scope of work for this project is regarding to all of the objectives that have been stated. The most important thing for this project is to understand clearly about the transmitter system in radio frequency like the basic and standard operation of the system, the component that been used for the system and the advantages and disadvantages of the system. It also important to know the parameter and characteristic that will affect the APS system.
This project is to build a transmitter that transmits a 700MHz carrier signal. A direct-conversion approach is used in developing this RF transmitter. A signal bandwidth of 30MHz is inserted to the filter to leave only needed frequency signal. Then, an up conversion mixer is used to converts the signal into 700MHz RF carrier signal for transmitting. Power amplifier (PA) and Gain block provide gain to the system.
1.4 Project activity
The first need to know is to understanding the problem related with the final year project`s title that is this project of Direct Conversion 700MHz RF Transmitter. Then the understanding with literature review like survey and project management must be mastered before this project can be realized. The next step involved is in fabrication process. The PCB board layout must be design, assembly and tested precisely so it can work according to the specification. The final step involved is analyzing the result and conclude the finding if there are any.
(2)
1.5 Organization of the Report
The structure of this project report was planned to provide a clear explanation about the project entirely. This thesis is divided into five chapters.
Chapter I introduces background, objectives, scope of work, project activity, and company background. In this chapter, some general knowledge about transmitting system will be presented. Due to the subsidizing from TM R&D for this project, there is some review on it.
Chapter II provides the literature review on the Transmitter system. It is about the process, the mechanism and the parameters that involved in the systems.
Chapter III describes in detail the methodology used during the project. There are 3 method that been used in this project which are calculation, simulation and measurement. In calculation part, the formula that been used to calculate in the system will be presented. But, the circuit for simulation part will be shown in chapter Four. For the measurement part, the measurement process will be introduced.
Chapter IV discuss about the result and the analysis. The result will have simulation and measurement data. The analysis and the comparison for the data will be included in this chapter.
Chapter V is about the conclusion for the project. The conclusion will be summarizing about the entire project. Recommendation for the project will also be included in this chapter.
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1.6 Company background
TM R&D, an entirely owned subsidiary of Telekom Malaysia Bhd. It starts its operation on 1st January 2001 as the R&D support of future business of TM. It also has the vision to grow to be a leading force technology company in the marketplace through research, development and innovation in Information and Communication Technology (ICT) industry.
R&D management is only one of its kinds due to the unpredictable market demand for state-of-art product and services. To remain responsive and competitive, TM R&D introduced several Knowledge Management initiatives as a frame-work to manage and utilize the wealth of intellectual capital inside the organization.
At TM R&D, they get on both basic together with applied research activities. It also has aligned research programs to sustain the strategic theme that covers different technological focused areas. The research activities conducted beneath division of basic research are mostly correlated to the development of nano and micro sized device for the purpose of electronic and photonic application. TM R&D also focus on it design simulation, fabrication technology development, and testing to meet up standard and quality contingent and system integration [4].
(4)
CHAPTER II:
LITERATURE REVIEW
2.1 Introduction
This section explains about transmitter`s characteristic, parameters, transmitter architecture, and module of transmitter. Transmitter characteristic must me mastered out first before any designing can begin. In transmitter structure, there are many things and terms must be understood like transmit output power, gain, insertion loss, return loss, and other terms regarding this project.
2.1 Radio Frequency
Radio frequency (RF) was defined as a rate of oscillation in the range around 3 kHz to 300 GHz, which match to the frequency of radio waves, and the alternating currents that carries radio signals [5]. Here, RF generally refers to electrical rather than mechanical oscillations, although mechanical RF systems do exist.
(5)
The electrical currents oscillating at radio frequencies have particular properties that differ from direct current or alternating current. Energy in RF current can radiate from a conductor into space as electromagnetic waves or radio waves. This is the foundation of radio technology. Instead of penetrating deeply into electrical conductors, RF current actually flows along their surfaces known as skin effect. As a result, whilst the human body comes in contact with high power RF currents it caused burns called RF burns. The current can simply ionize air, creating a conductive path through it. It also flows through paths that contain insulating material, like the dielectric insulator of a capacitor. When circuit are conducted by an ordinary electric cable, RF current has a tendency to reflect from discontinuities in the cable such as connectors and travel back down the cable toward the source and causing state named standing waves, so RF current have to be carried by particular types of cable called transmission line [6].
2.3 Parameter
S-parameters or scattering parameters best explain the electrical performance of linear electrical networks when endure various steady state caused by electrical signals in communication design. S-parameters characterize a linear electrical network by matched loads instead of open or short circuit conditions. These terminations are easier to implement at high signal frequencies and the quantities are measured in power (dB) [7].
Lots of electrical properties of components like inductors, capacitors, and resistors may be uttered using S-parameters, such as Gain, Voltage Standing Wave Ratio (VSWR), Return Loss, Reflection coefficient, and amplifier stability. In the circumstance of S-parameters, scattering refers when traveling currents and voltages in a transmission line are affected when they meet up a discontinuity caused by the insertion of a network into the transmission line.
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Even though appropriate at low or high frequency, S-parameters are mostly used for networks operating at radio frequency (RF) and microwave frequencies where energy considerations and signal power are easily quantified than currents and voltages [8].
Due to the theory of S-parameters that is changed by means of the measurement frequency, the frequency must be specified for any S-parameter measurements declared, in calculation to the characteristic or system impedance. S-parameters are generally represented in matrix form and comply with matrix algebra. By having two ports only in microwave network, that is an input and an output, the S-matrix has four S-parameters, designated like below:
S11 S12
S21 S22
These complexes quantities in fact contain eight divided numbers (real and imaginary parts), or modulus and phase angle, of each of the complex scattering parameters. If the output port 2 is terminated, the transmission line is connected to a matched load impedance and giving rise to none reflections, and produced no input wave on port 2. The input wave on port 1 gives rise to a reflected wave at S11. And a transmitted wave at port 2 which absorbed in termination on port 2. The transmitted wave dimension is S21. If the network used has none loss or gain, the output power must equal the input power and so in this case |S11|2 + |S21|2 is matched [9].
Therefore, the sizes of S11 and S21 determine the input power that splits between the potential output paths. Clearly, if 2-port microwave network represents a good amplifier, S11 needed are rather small and S21 are quite large. In general, the s-parameters stated much power comes back or out when the