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LAB GUIDE BOOK

TELECOMMUNICATION ENGINEERING LAB WORK

C O D E : E N E E 6 0 0 0 2 6

For Bachelor Program

TELECOMMUNICATION LABORATORY Department of Electrical Engineering Faculty of Engineering, Universitas Indonesia Kampus UI Depok, West Java16424 Phone: (021) 7270077, 7270078 ext. 131

2015 EDITION

ENGLISH VERSION

LABORATORY MANUAL

TELECOMMUNICATION ENGINEERING (ENEE 610025) For International Class Student of Electrical Engineering

Published by Laboratory of Telecommunication Department of Electrical Engineering Faculty of Engineering Universitas Indonesia 2015

Supervisor : Dr. Fitri Yuli Zulkifli, S.T., M.Sc. As head of laboratory of Telecommunication DTE FTUI

Editor : Muhammad Erfinza Fariz Azhar Abdillah Author : Adhitya Satria Pratama Aisyah Ina Gustiana Budiman Budhiardianto Sayid Hasan Muhammad Haekal

Rifqi Ramadhan Angga Hilman Hizrian Ubay Muhammad Noor Mursid Abidiarso Yonathan Raka Pradana Irfan Kurniawan Rian Gilan Prabowo

For internal Universitas Indonesia use only! All rights is reserved. Reproduction and/or duplication of a part or entire of this document in any forms are prohibited.

Laboratory Manual Telecomunication Engineering 2015 2

Safety Instructions

OPERATION OF EQUIPMENT TO EACH PRACTICUM IS REQUIRED TO BE ACCOMPANIED BY ASSISTANT OF LABORATORY. PLEASE READ THESE GENERAL SAFETY INSTRUCTIONS AND SAFETY INSTRUCTIONS IN EACH MODULE AND PRAY BEFORE DOING PRACTICUM.

You must read practical guide and pay attention to safety instructions on each module before practicum.

Please keep a mobile phone or other communication electronic devices in order to focus. It is forbidden to play a mobile phone or other electronic devices for practical communication.

Always be carefull when using electrical devices. Turn off the equipment before unplugging or changing the configuration of equipment . Be careful of static electricity hazard.

It is forbidden to eat and drink when operate the equipment during the experiment.

You must wear proper shoes (covering the legs) to avoid the danger of electrical shock and hit objects in the lab. students who do not wear shoes banned from the lab, except for the pain does not allow wearing shoes and permission assistant..

If the event of a fire, a fire extinguisher is located at the left of the entrance. If things happen unexpected, please do emergency procedures calmly.

Some Equipment lab uses high-frequency radio. Avoid direct contact with the body radiation. Forbidden to peek the Waveguide at the lab. Always be careful in the experiment.

Smoking is clearly prohibited in environment of Faculty of Engineering

Forbidden to joke around and fight in the Telecommunications Laboratory during the activity

LABORATORY ASSISTANT HAS RIGHT TO REPRIMAND OR PUNISH THE STUDENT WHO ARE CONSIDERED HARMFUL OR DO THINGS NOT DULY DURING PRACTICUM.


Preface

This lab guide book has been adapted over the years to meet

students‟ needs especially in the study of telecommunication

engineering at Electrical Engineering Dept. This guide book is

purposed to provide a user-friendly manual book to help students

understand practical aspects of telecommunication engineering

by doing experiments in the laboratory.

This book contains 10 modules to be done on Telecommunication Engineering Lab

Work. Each module on this book contains complete instructions on technical principles

and procedures in the lab consisting of the objectives, basic theory, equipment and

experimental procedures.

I would like to thank all those who have helped in this book preparation. I and all the

assistant team would be grateful for your suggestions to improve this book in the future.

I wish this book can be used well by the students and help you to understand the

telecommunication engineering clearly.

Depok, 23 September 2015

Head of Telecommunication

Laboratory

Electrical Engineering Dept., FTUI

Dr. Fitri Yuli Zulkifli, S.T., M.Sc.

NIP. 19740719 199802 2 001


Rules of Telecommunication Engineering Laboratory(ENEE 610025)

Telecommunication Engineering Laboratory (ENEE 610025)

Term 2015/2016-01

1. You must attend the entire series Practicum Telecommunication Engineering

consisting of 10 Module Practicum.

2. You must read the Safety Instructions and General Safety Instructions on each

experimental module to avoid things that are not desirable.

3. During a series of practical activities (including the current Test Introduction), every

person shall dress modestly, wearing a collared shirt and shoes. If the dress does not

fit the rules, then it should not follow the series of practical activities.

4. You must perform lab preparation materials, through the lab module, course materials,

and other related sources.

5. You should bring practical and task cards and collected preliminary to the lab assistant

when it will begin.

6. The person who forgot to bring the lab card will be subject to a reduction in value.

7. Everyone is obliged to follow the Test Introduction.

8. The reason for that is acceptable is sick (included Certificate of Physician / Hospital),

sudden disaster, and force major (flood, fire, etc.).

9. Everyone is obliged to work and collect Task Practical Introduction before following.

10. Each person must fill out an attendance list Preliminary Test, Practice and Collecting

Additional Tasks.

11. Tolerance for each Module Practicum delay was 15 minutes. If passing a

predetermined time without giving any clear reason, then the practitioner can not

follow the lab module.

12. You are allowed to exchange praktikan schedules with other groups on the same

module (provided that the two groups have passed the Preliminary Test), with the

notice no later than the H-1 to the practicum coordinator.

13. If you do not follow the laboratory activity, the module value is zero.

14. Rating:

Component Precentage

Preliminary tests 5 %

Introduction task 10 %

Practicum 35 %

Form 40 %

Additional tasks 10 %


15. The practical value is determined by the behavior and activity of the practitioner during the

practicum, including during oral test before the lab begins.

16. Additional tasks performed in double folio striped paper and collected no later than 1 x 24

hours after the practicum ends.

17. All licensing and complaints please delivered to the Laboratory Coordinator

Head of Laboratory of Telecommunication

Dr. Fitri Yuli Zulkifli, S.T., M.Sc.

NIP. 197407191998022001

International Class Cordinator

Angga Hilman Hizrian

NPM 1206260860


Asistant of Laboratory

Telecommunication Engineering Laboratory (ENEE 610025)

Term 2015/2016-01

RIFQI RAMADHAN

Teknik Elektro 2012

Cordinator of Asistant

087781870722

[email protected]

UBAY MUHAMMAD NOOR

Teknik Elektro 2012

Cordinator of Telecommunication Engineering Laboratory for Reguler and Paralel Class

087788945594

[email protected]

ANGGA HILMAN HIZRIAN

Teknik Elektro 2012

Cordinator of Telecommunication Engineering Laboratory for International Class

085966116036

[email protected]

MURSID ABIDIARSO

Teknik Elektro 2013

085717108241

mursid.abidiarso @gmail.com

MUHAMMAD HAEKAL

Teknik Elektro 2012

081316106027

[email protected]

FARIZ AZHAR ABDILLAH

Teknik Elektro 2013

085692612648

[email protected]

MUHAMMAD ERFINZA

Teknik Elektro 2012

083898345760

[email protected]

RIAN GILANG PRABOWO

Teknik Elektro 2013

087808052796

[email protected]

IRFAN KURNIAWAN

Teknik Elektro 2013

085695133317

[email protected]

YONATHAN RAKA PRADANA

Teknik Elektro 2013

081329078777

[email protected]

mailto:[email protected]





Contents

Safety Instructions .................................................................................................................... 2 Preface ........................................................................................................................................ 3 Rules of Telecommunication Engineering Laboratory(ENEE 610025) ............................... 4 Asistant of Laboratory .............................................................................................................. 6 Contents ..................................................................................................................................... 7 Introduction of Telecommunications Engineering ................................................................ 9

Objectives ................................................................................................................................ 9

Classical Era: Wired Telecommunications Network ............................................................... 9

New Era: Wireless Telecommunications Networks .............................................................. 10

Explosions of Technology: Cellular Communications ........................................................... 12

New Needs: Multimedia Broadband Communication ........................................................... 15

Transmission Lines ................................................................................................................. 17

Objectives .............................................................................................................................. 17

Fundamental Theory ............................................................................................................. 17

Equipment .............................................................................................................................. 23

Procedure .............................................................................................................................. 27

Amplitude Modulation ............................................................................................................. 29

Objectives .............................................................................................................................. 29


Equipment .............................................................................................................................. 40

Procedure .............................................................................................................................. 40

Frequency Modulation ............................................................................................................ 43

Objectives .............................................................................................................................. 43


Equipment .............................................................................................................................. 49

Procedure .............................................................................................................................. 49

Telephony System ................................................................................................................... 51

Objectives .............................................................................................................................. 51



Equipment .............................................................................................................................. 55

Procedure .............................................................................................................................. 55

PULSE CODE MODULATION DAN TIME DIVISION MULTIPLEXING .................................. 57

Objectives .............................................................................................................................. 57


Equipment .............................................................................................................................. 62

Procedure .............................................................................................................................. 63

DIGITAL MODULATION ........................................................................................................... 66

Objectives .............................................................................................................................. 66


Equipment .............................................................................................................................. 69

Procedure .............................................................................................................................. 70

DIGITAL LINE CODING ........................................................................................................... 73

Objectives .............................................................................................................................. 73


Equipment Equipment ........................................................................................................... 76

Procedure .............................................................................................................................. 76

FILTER FINITE IMPULSE RESPONSE ................................................................................... 78

Objectives .............................................................................................................................. 78


Equipment .............................................................................................................................. 83

Procedure .............................................................................................................................. 83

RADIO LINES SIMULATION USING RADIOMOBILE SOFTWARE ...................................... 86

Objectives .............................................................................................................................. 86


Equipment .............................................................................................................................. 87

Procedure .............................................................................................................................. 87

REFERENCES .......................................................................................................................... 89


Module 1

Introduction of Telecommunications Engineering

Objectives

By studying this Introduction module, you are expected to know in general about

Telecommunication Engineering. Topics that will be introduced is about the development of the

Cellular Telecommunications Technology and its application in daily life.

Classical Era: Wired Telecommunications Network

Today we see how the development of mobile handsets are becoming one of the most

popular gadgets in the world. It is estimated that in 2008, there were 1.4 billion television sets in

the world and the number of mobile phones has reached three times that number. Institute of

Engineering and Technology estimates that by the end of 2012 there were more mobile phones

than the number of human population on earth.

Telecommunications means of distance communication using a specific medium.

Communication can be divided into three types, namely:

1. Communication One Direction (simplex). Examples: pagers, television, radio.

2. Two-Way Communication (duplex). For example: phone

3. Semi Two-Way Communication (Half Duplex). For example: walkie talkie

Telecommunications themselves began to grow since Alexander Graham Bell invented the

telephone. Telecommunications eventually evolving to enter the era of mobile telecommunications.

Mobile telephony or mobile telecommunications technology enabling wireless communication to

receive or make phone calls. Mobile telecommunications considers each geographical area made

up of small cells that can be interconnected. Each cell was covered by local radio transmitter and

receiver that is strong enough to deal with cellular phone itself, in this case by using a mobile

terminal. A collection of these cells form the radio access network and the radio frequency used for

transmitting calls and data used between the cells. Voice and data to be exchanged is transmitted

through the mobile network that consists of a radio access network and the core network of the

mobile operator.

Telephony system began to develop in 1838 when Samuel Morse invented the signaling

system of dots and dashes to the alphabet so complex messages can be sent and received more

easily. Just six years later, the system is backed up by the US Congress until the system is


installed the first telegraph line in the world with copper wires between Washington and Baltimore

as far as 40 miles.

At that point, the copper cables ranging connect various major cities in the United States

were built and operated by Western Union, which is still active today as an interstate money

transfer agent. Copper cabling system is also being developed in Europe and began the era of

information exchange via copper cable systems.

Figure 1. 1. The Trans Atlantic cable is operated by Great Eastern.

In 1851, copper cables under the sea began operating between France and Britain then

followed transatlantic submarine cable in 1858. The level of complexity of the submarine cable is

high enough to make cooperation project Europe-USA has become one of the major engineering

projects of its time , Needed five tries to get a compact submarine cable completed. Unfortunately,

these cables are used by engineers with great enthusiasm that transmit voltage too high via this

cable to a system failure just three weeks after the operation. In 1865, the construction of the Trans

Atlantic submarine cable which both started as far as 1200 miles, but still failed. The third project

was initiated in 1886 by Brunel's Great Eastern as far as 1686 nautical miles between Ireland and

Newfoundland and proceeded without major obstacles. After that, Great Eastern began to manage

this network and divide it into two and there are two operating transatlantic cables.

The next major development in 1876, Alexander Graham Bell experimented with a

diaphragm vibrate a needle on the water to vary the current in the circuit, which is known as a

liquid transmitter. With this device, voice conversations over copper wires occur first in the world

even if only between two adjacent rooms with a tool called the telephone. Bell then repair these

findings for five months and ultimately can conduct voice conversations as far as five miles.

Western Union and then develop their Morse telegraphy system via the phone network. New Era:

Wireless Telecommunications Networks

In 1880, Bell also made the first wireless communication using a device Photophone.

Photophone using a beam of light to deliver voice signals between two buildings within 215 meters.


The use of the atmosphere as a medium for the propagation of the wave which has not been

developed at that time led to the current wireless communication technology was not developed

until the fiber optic cable technology developed in the 1920s by the US military. The new theory of

the laser was developed by Einstein in 1917 and requires a long time until the laser models that

operate properly produced.

Figure 1. 1. The First Microphone

Post World War II, the wireless phone was developed by AT & T, United States. At first,

the mobile phone like a walkie-talkie-like communications in which only occur alternately in one

direction (simplex). Users also have to look for available frequencies between 35 MHz - 150 MHz

to hold a telephone conversation. To enable phone conversation, the mobile phone users have to

carry a very large battery weighs up to 35 kg.

In England in 1912, the General Post Office is the first company to build and operate

infrastructure telegraphy and telephony calls using a commercial copper wires. In 1981, the

General Post Office was split into two, namely the Post Office and British Telecom. British Telecom

is the parent company Cellnet which gave entry to the mobile phone market is very profitable.

Cellnet himself later changed to O2.

Figure 1. 2.Fiber Optic Wire

In 1970, a fiber optic cable was discovered by Corning Glass Works and has been proven

to deliver signals with speeds of 45 Mbps by using a signal amplifier every 10 km. In 1981, fiber

optic cable single-mode find and deliver new breakthrough in signal transmission fiber optic cable.


In 1987, the second generation of fiber-optic cable operating at speeds of 1.5 Gbps with

reinforcement at every 50 km. In 1988, Trans Atlantic fiber optic cable was developed. The third

generation technology fiber optic cables capable of operating at a speed of about 2.5 Gbps with

reinforcement at every 100 km.

Explosions of Technology: Cellular Communications

Cell phone was first launched in 1985 in the UK by Vodaphone and Cellnet, which later the

two companies merged into O2. However, the mobile phone is not very practical because it weighs

20 kg with a very large battery systems. At that time, we could see the entrepreneurs carrying two

bags at once, namely file bag and telephone equipment.

In 1992, fourth-generation technology is developed with fiber optic cable Wavelength

Division Multiplexing principle which makes it able to double the speed twice every six months until

2006 has reached a speed of 14 Tbps with boosters every 160 km. This optical fiber cable

technology that allows us to enjoy the cable TV and broadband services (broadband) to various

regions. However, the cost to deploy broadband technology based on fiber optic cables is huge

and the risk is too high. This causes the need for broadband wireless communications is very high

until now.

Figure 1. 3. Development of Mobile Cellular Phone

In the previous description, we have discussed about the birth and development process in

brief communication with the wired network since the invention of Morse code in the 1800s to the

development of optical fiber communication system that began in the late 20th century. When the

fiber optic cable is able to conduct a conversation with a very large number of simultaneous, we

also need to look at the first steps of wireless personal communications that subsequently will be

an explosion of technology that is rapidly until now.

In principle, there is a very important difference between the first generation mobile

communication system with subsequent developments. In the first generation (1G), wireless

communications are still using analog systems. Sound transmitted directly as spoken by humans.

The development of 2G and next generation network transformation into a digital system, where


the voice is sampled and broken into data before it is transmitted. The sending side will then

reorder the data packets into voice intact that we can hear. This is the beginning of the era of

digital communication is growing very rapidly.

The first generation of wireless telecommunications system was launched in Japan in 1979

by NTT and capable of covering 20 million inhabitants Tokyo with 23 base transmission station

(BTS) and finally in 1984 had been able to cover the whole country of Japan. 1G networks began

in Europe by Nordic Mobile Telephone and in 1981 has included wilayan Sweden, Finland and

Denmark. In 1983, Motorola began the development of cellular networks in America and on

January 1st 1985, Vodaphone launch the era of mobile phones in the UK.

Figure 1. 4. Cellular Phone developed by Motorola

1G early generations developed in the 80s and still use analog systems. Analogue

systems using FDMA (Frequency Division Multiple Access), which allows to distribute the

allocation of frequencies to each customer in the cell. The technology used in analog system is

commonly known as AMPS (Advanced Mobile Phone Service) operated in the 800 MHz band.

1G is a shortage of generation size is too big to handle, battery performance is poor, traffic

capacity is small, and the sound is not clear. At that time the phone is used is still large enough

and beterainya relatively wasteful.

The second generation of mobile telecommunications is currently digitlal entering an era in

which Europe began to find a GSM (Global System for Mobile Communication) and the US began

to develop cdmaOne (Code Division Multiple Access). GSM is a TDMA (Time Division Multiple

Access) using the carrier band of 200 KHz. With GSM, radio frequency bands used for reusable

carrier during a radio transmitter to the same frequency are not in the adjacent cell. While

cdmaOne using different technologies, namely spreadspectrum, where the radio spectrum is

divided into multiple carrier width of the ribbon reach 1.23MHz. In CDMA, the user using the same

frequency at the same time making it more efficient.

GSM technology is currently the most widely used in the world because it has a very wide

roaming capability. CDMA advantages compared to GSM is the sound clearer, larger capacity, and

the ability to access higher data.


This 2G network SMS service start in 1993 and developed into a prepaid system began in

the late 1990s. Nordic Mobile Telephone begin introducing a system of payment by mobile phone

with the vehicle parking systems and vending machines Coca-Cola so the technology is a

promising new method of payment in 1998. The first commercial system that works like a credit

card began in 1999 in the Philippines by two operators , the Globe and Smart.

Advertising services on mobile phones first appeared in Finland in 2000 that allows mobile

phone users receive the latest news of a brand that wants to follow. This service is also open sales

opportunities ringtone to individual consumers. The ringtone was developed from monoponik to

become polyphonic. Polyphonic ringtone then began shifting with MP3 technology that developed

later. In 1999, NTT DoCoMo of Japan presenting the first mobile internet service in the world, but

the speed of service is still limited because of the technological limitations of 2G.

Since very little data access capabilities of GSM, reaching only 9.6 Kbps, began to develop

GPRS (General Packet Radio Data Services). Then the technology was introduced Wireless

Application Protocol (WAP), but the results are not so satisfactory. Until finally GPRS was

developed to be able to access data at speeds up to 115 Kbps and throughput only 20-30 Kbps.

GPRS also enables Internet access from anywhere and in real time. GPRS is less desirable

because the price is quite expensive at that time. Growing technology again is EDGE (Enhanced

Data for Global Evolusion) who only had implemented a minute, at speeds up to 3-4 times the

speed of GPRS.

The development of 3G services, initiated by NTT DoCoMo in early 2001 and the first

commercial 3G network was launched in October 2001 with WCDMA (Wideband Code Division

Multiple Access). In 2002, the 3G network was launched in South Korea and in the United States

named Monet. Both use a standard CDMA / EV-DO which is the Betamax of 3G and Monet also

had collapsed. The second network with WCDMA standard launched by Vodaphone KK (currently

known as Softbank) in Japan. At the same time in Europe, also developed by Three / Hutchison

Group in Italy and the UK.

The third generation is a continuation of GSM, GPRS, EDGE, and CDMA generations ever

before. This advanced technology called the Universal Mobile Telecommunications Service

(UMTS). The goal is to provide data access speed is higher achieve 385 kbps at a frequency of 5

KHz. The selected modulation technique is Wide-CDMA UMTS. Used on WCDMA radio frequency

of 5 MHz in the 1900 MHz band. HSDPA (High Speed Downlink Packet Access) is a continuation

of UMTS that uses radio frequency of 5 MHS by reaching a speed of 2 Mbps. To apply the

necessary UMTS greater costs due to pay a license to the government and the 3G vendor, adding

the base station, and the cost of capex (capital expenditure) and OPEX (operational expenditure)

others. Application of 3G among others for video calls, live streaming, and other broadband

multimedia services.

In 2003, 4 re-launched 3G services in Europe, two of which use WCDMA technology and

the other two use CDMA / EV-DO. WCDMA more developed than CDMA / EV-DO for nearly two-


thirds of the mobile telecommunications market and adopt this technology has become the industry

standard technology for 3G services. Discovery technology HSDPA (High Speed Downlink Packet

Access) enables mobile internet services faster with a speed of 1.8 Mbps to 14.4 Mbps. The

HSDPA service and then continue to grow until its own has become a lifestyle for some people.

Then the third generation is enriched again with the release of generation 3.5G. Speeds up to 3.6

Mbps so that it can serve faster multimedia communications, such as Internet access and video

sharing.

New Needs: Multimedia Broadband Communication

Figure 1. 7. Smart Phone.

Broadband internet service starts with the use of dongles or what is known as a modem so

that we can enjoy the high speed internet service on laptops flexible. Then the development of

technology to make cellular phone capable of functioning as an "office" with electronic mail

services and organizer. Currently, real-time video stream service we can also enjoy the hands

easily. In fact, video conversation also had grown although its development is less well received. At

this time was, we finally know the mobile phone as a smartphone, smart phone.

This time we started to move towards 4G services in the second decade of this millennium.

4G standards have extremely high data rates up to 100 Mbps on the condition of high mobility (in a

car or train) and up to 1 Gbps at a low mobility condition (eg pedestrian environment or stationary

users). This high speed technology uses the principle of OFDMA (Orthogonal Frequency Division

Multiple Access) with various encoding algorithms to high speed was achieved. Some of the

advantages in addition to high-speed 4G technology include architectural flat structure for all the

technologies and low latency.

4G technology known first is WiMAX (Worldwide Interoperability for Microwave Access) in

2006 that offers speed up to 128 Mbps in download and 56 Mbps flow in the upload stream.

WiMAX slowly abandoned due to inefficiency and lack of support services with high mobility. LTE

later present in 2009 that offers speed up to 100 Mbps in download and 50 Mbps flow in the upload

stream. Also known as HSPA + (High Speed Packet Access), which operates at speeds up to 84

Mbps in download and 22 Mbps flow in the upload stream. LTE developments are increasingly


supported by the development of MIMO antenna system (multi input multi output) and smart

antenna which can improve the performance of high-speed services.

In the United States, AT & T, Verizon, and Sprint has started a network based on LTE and

operate optimally in 2013. Then there were plans LightSquared will use satellites to reach 92% of

the US population with LTE service in 2015, although with this technology speed will be a separate

consideration.In Indonesia, commercial 4G service started in 2010 by PT. Firstmedia, Tbk with

trademark Sitra. Sitra WiMAX provides high-speed broadband services in Indonesia's first wireless

in congested areas such as Greater Jakarta, North Sumatra, and Aceh. Sitra itself is an expensive

BWA license holders in the Greater Jakarta area. But with the development of technology, WiMAX

is becoming obsolete because of the huge costs and other technology constraints to be replaced

by LTE. Telkomsel became the first operator to conduct trials of 4G LTE network at the APEC

conference in Bali in October 2013. The network is operated at a frequency of 1800 MHz with a

bandwidth of about 5 MHz.At the end of 2013, PT. Internux then launched the first commercial LTE

4G services since Nov. 14. 2013 at the Greater Jakarta area coverage. The market potential is

expected to reach 30 million people. 4G LTE technology used to use the principles of TDD-LTE

(Time Division Duplex-LTE) at a frequency of 2300 MHz.

4G development in Indonesia is still impressed road in places. The main issues that block

is the issue of government regulation that is not well finished. Besides placing the appropriate

frequency for 4G services is still unclear. In the frequency band above 1800 MHz is still necessary

to reset the frequency or frequency refarming, while the 700 MHz frequency band is still

constrained analog television system that has not been moved to digital television.Today also

started to develop 5G services are much more sophisticated. In contrast to 2G services to 4G, 5G

is a radio technology that will replace the single access makrosel. 5G service is a combination of

access technologies are licensed and unlicensed radio access or optimization. 5G promising high-

speed service with latency to zero. This technology is supported by the development of MIMO

antenna technology and the use of millimeter waves for communications applications.

Figure 1. 7. Scenario 5G Services.

Written by some sources.

Adhitya Satria Pratama, Teknik Elektro 2010.

---o0o--


Module 2

Transmission Lines

In this assignment the measurement of voltage standing wave ratio (VSWR) of waveguide

components is undertaken using a waveguide slotted-line and probe detector. Voltage standing

wave ratio, invariably abbreviated to VSWR, is one of the fundamental parameters used in

specifying component performance. It quantifies the degree of mismatch a component presents to

the waveguide feed line.

The concept of impedance in waveguides and the use of the Smith Chart in impedance

and matching calculations are introduced. The measurement of impedance of a waveguide

component is carried out and the results used to determine the position of a capacitative probe to

effect matching.

Objectives

After following this lab, you are expected to:

Understand the concept of Voltage Standing Wave Ratio in the transmission line;

Understand the concept of impedance and admittance in the transmission line

Understand how to use Smith Chart to determine the value of impedance and

admittance in the transmission line.

Fundamental Theory

Fundamental of Transmission Lines

Three types of channels transmisidual plural-conductor encountered are twin lead, coaxial

and microstrip .The transmission line is quite familiar twin lead is used to connect the antenna to

the TV aerial, while the coaxial typically used to connect devices with high frequency. In the coaxial

line, cable consists of three layers: the innermost part jejari a conductor, dielectric layer berjejari b,

and the conductor layer on its outer part. Microstrip widely used in circuit board level. In Microstrip

line consists of copper that coats the substrate of alumina (Al2O3).

Twin Lead

Coaxial

Fundamentals of Electromagnetics With Engineering Applications by Stuart M. Wentworth

Copyright © 2005 by John Wiley & Sons. All rights reserved.

Transmission line examples along with schematic cross sections. A quarter is

shown for scale.




shown for scale.


Mikrostrip Figure 2. 1. Three types of transmission line.

The types of transmission line that mentioned before can be modeled as a simple two-pole

configuration. In Figure 2.2., Visible parameter transmission line distributed series, namely R

'(resistance per meter) and L' (inductance per meter) and in parallel, namely G '(conductance per

meter) and C' (capacitance per meter) , Apostrophe indicates the value distributed to unit length

(meters). Distributed parameter is more than doubled to Δz differential segment length in meters

and generate value elements of "pure" R, L, G, and C.

Figure 2. 2. Parameter distributed on the transmission line with a certain segment length differential. (a). Transmission line, (b) Modeling the transmission line.

When a signal travels along a conductor, it will naturally develop resistance. This

resistance is connected in series and its value is very small for an excellent conductor. However,

the resistance value is still there and should be taken into account. Also based on the legal theory

of Ampere and Biot-Savart, there is a series inductance along the transmission line.

The two cables on two poles modeling transmission line in Figure 2.2, Separated by a

dielectric material (eg, air) which acts as an ideal insulator. Dielectric actually conduct real small

amount of current shunt. The parameters used to identify small amount of current is the shunt

conductance (the inverse of resistance). Brother can distinguish between the conductance arises

due to the dielectric properties and has nothing to do with the series resistance on the transmission

line. Then the two conductors, there is a shunt capacitance between the two.




shown for scale.




shown for scale.


For the geometry and composition of certain materials, distributed parameter transmission

line can be calculated by the following formula:

abG d

ln

2'

(2.1)

abC

ln

2'

(2.2)

abL ln2

'

(2.3)

c

f

baR

11

2

1' (2.4)

Basic parameters of Transmission Line

In Figure 2.2b. calculated instantaneous voltage and current on each end of the segment.

You notice that v (z, t) shows the voltage as a function of time t and distance z. Δz notation shows

the distance difference between the starting point and end point. Similarly, in the current.

Telegraphic equation is the basic equation that takes into account the transmission line

currents and instantaneous voltage on the transmission line segments so that the transmission line

can be seen as a model of two poles. These equations describe the basic characteristics of the

transmission line, namely:

1. The propagation constant, which describes the propagation characteristics of the waves on

the transmission line.

j

CjGLjR

'''' (2.5)

where α is the real component, namely the attenuation constant and β is the imaginary

component, ie the phase constant..

2. The characteristic impedance, which is the ratio between the amplitude of the voltage

wave propagating in the positive direction of the amplitude of the current wave propagating

in the positive direction.

CjG

LjRZ

'

''0 (2.6)

3. The characteristic impedance on the channel without loss (lossless line). A channel can be

assumed as a channel without a loss if the value of R 'is much smaller than ωL' and G 'is

much smaller than ωC' so that the value of R '= G' = 0.


'

'0

C

LZ (2.7)

Terminated Transmission Lines

Figure 2. 3. The transmission line that is terminated by a load. Positive direction indicates the direction

toward the load side, and negative indicates the opposite direction.

Some interesting phenomenon arises when a transmission line terminated with a load that

is placed at z = 0. The load impedance is the ratio between the voltage of the current on the load

side.

00

000

VV

VVZZ L

(2.8)

where Z0 is the characteristic impedance of the transmission line. Equation 2.8 can be rearranged

into:

0

0

0

0 VZZ

ZZV

L

L (2.9)

From equation 2.9. it appears that if the value of the load impedance ZL is equal to the

characteristic impedance Z0 channels, then no waves are reflected back to the source. This

condition is referred to as the state of the corresponding (matching).

In the case where the load impedance is not equal to or does not match line impedance

(mismatched), there is waves that bounce back toward the source and is considered harmful. The

level of impedance mismatch of the channel expressed in the reflection coefficient parameter

(refflection coefficient) on the load side, namely:

0

0

0

0

ZZ

ZZ

V

V

L

LL

(2.10)

In the short-circuit load (ZL = 0), the corresponding load (ZL = Z0), and load open circuit

(ZL = ∞) value of the reflection coefficient, respectively - 1, 0, and +1. Superposition of these

waves form a standing wave (standing wave), where the ratio between the value of the maximum


amplitude of the wave superposition minimum amplitude wave superposition expressed in

parameter VSWR (voltage standing wave ratio).

L

LVSWR

1

1

(2.11)

which ranges from 1 to infinity.

At any point along the transmission line, you can compare the total voltage of the current

total, which is known as the input impedance.

lZZ

lZZZZ

L

Lin

tanh

tanh

0

00

(2.12)

In the case of the channel without loss, the input impedance can be calculated as:

ljZZ

ljZZZZ

L

Lin

tan

tan

0

00

(2.13)

Figure 2. 6. The input impedance of the transmission line.

There are two ways to determine the value of VSWR, :

1. Direct Method

Direct method is done by measuring the current values along the transmission line. The

measurement results will be obtained current value at any point on the transmission line. VSWR

graph obtained by plotting each value stream at any point on the transmission line.



The terminated T-line can be replaced by an equivalent lumped-element input

impedance.


2. Indirect Method (Double minimum method)

The indirect method is used to improve the direct method if the value of VSWR> 10.

Detector detects the minimum signal. Then the detector is moved in two places where the signal

has ampitudo twice the minimum signal amplitude. Where the second distance, d, can be used to

determine the VSWR with:

gdE

EVSWR

/sin

11

2min

max (2.14)

Figure 2. 1. Indirect Method .

In this experiment, you will do a VSWR measurement techniques water slotted coaxial line,

as shown in Figure 1.8. A probe can be moved sliding along the channel to measure the electric

field occur ampltudo. In the measurement using a slotted line VSWR detector, there are

characteristics possessed square law detector:

2kei (2.15)

2

2min

2max

min

max VSWRke

ke

i

i (2.16)

min

max

i

iVSWR (2.17)

with i is the DC output current, k is a constant, and e is the voltage.

Figure 2. 2. Slotted coaxial air line Method.


A large electric field along the waveguide (waveguide) can be detected using a

slotted-line. The electric field is captured by the detector diodes in the probe. By sliding

the probe along the channel, the value of the electric field tercuplik. Depth probe on-line

slotted channels need to be considered, because the probe is inserted in the value of the

resulting output will be even greater. Good depth is not too deep or not too shallow, too

deep because otherwise it will cause a perturbation (disruption) which mengkopling field

in the channel so that its value will be getting bigger and inaccurate. In the detector also

given custody stub used to minimize the effects of loading (capacitance and resistance

shunt) on the transmission line.

Diagram Smith

Smith chart is a diagram which is used to understand the characteristics of the

transmission line and microwave circuit elements. This diagram consists of real and

imaginary numbers, where the real component is shown by a full circle, while the

imaginary component shown by a curved shape. Some characteristics of the transmission

line can be calculated with the Smith Chart include the VSWR, the load impedance,

admittance load, and the reflection coefficient. Based on the Smith chart can be

determined whether the conditions of the transmission line matching or not..

Equipment

This module uses lab equipment Microwave Trainer (MWT530) manufactured

Feedback Instruments Ltd. Equipment used in Table 1.1 below.

Table 2. 1. Equipment used in Transmission Line Module.

No Tool’s Name Quantity

1. Microwave Trainer Board 1

2. Variabel Attenuator 1

3. X-band CW Gunn Oscilator Source 1

4. Slotted line 1

5. Probe diode detector 1

6. Terminal hubung singkat 1

7. Terminal resistif 1

8. Waveguide Antena horn 1

9. H-plane tee 1


1. Microwave Trainer Board

Figure 2.9 Microwave Trainer Board

2. Variabel Attenuator

Is a resistive vane-central slot type; used to set attenuation level and control

power transmission in waveguides. Maximum attenuation vane setting 0◦ approx. 36

dB; minimum at 90ᵒ less than 1 dB.

Figure 2.10 Variabel Attenuator

3. X-band CW Gun Oscilator Source

Frequency:fixed 10.687 Ghz

Output Power: 10 mW typical; 5Mw minimum.

Figure 2.11 X-band CW Gun Oscilator Source

4. Slotted line

Waveguide slotted line; for sampling electric field pattern in waveguide; used

with probe detector to measure guide wavelength, VSWR and impedance.


Figure 2.12 Slotted Line

5. Probe diode detector

Probe detector, diode detector mounted in coaxial section with inner conductor

acting as a probe;used in conjunction with slotted line and directional coupler to detect

microwave signals. The diode detector in waveguide mount itself is used to rectify

microwave signals for their detection; at low power levels diode detector output current

is directly proportional to the microwave power being detected.

Figure 2.13 Probe diode detector

6. Short circuit plate

Metal plates used to short-circuit waveguide section; employed in impedance

measurements to determine reference planes, also used to measure guide

wavelength and crystal detector law in conjunction with slotted line.

Figure 2.14 Short Circuit Plate

7. Resistive termination


Is a waveguide section containing a taper lossy material to absorb incident microwave

signals; ideally should absorb totally incoming signals without any reflection- it then

acts as a matched load.

Figure 2. 15 Resistive Termination

8. Waveguide horn antenna

Is an important microwave antenna widely used as a feed to microwave parabolic

reflectors in radio, satellite, and radar systems, and also as an antenna in its own right.

Figure 2.15 Waveguide horn antenna

9. E-plane tee

Acts as a power divider in the plane containing the incident E (electric field).

Figure 2.11 E-Plane Tee


Procedure

WARNING!!! Although the microwave power levels generated by the equipment

are below 10 mW and not normally dangerous, the human eye can suffer

damage by exposure to direct microwave radiation. Therefore: NEVER look

directly into an energized waveguide.

Measurement of VSWR using Direct Method

1. Set up the equipment as shown in figure 2.12 .

2. Set up the switch conditions on the console as follows:

Amplifier and detector: switch to detector output.

Left-hand keying switch: switch to internal keying.

Right-hand switch: initially off

Figure 2.12

3. Set the sensitivity to mid-position. Set the attenuator at position 20°. After switch

on the console power supply, the main green switch, then energize the microwave

bench by switching the right-hand switch on.

4. When the detector probe is moved along the slotted line, then the value of current

will vary. Adjust the sensitivity and, if necessary, the attenuator setting to obtain a

meter reading close to full-scale deflection.

5. Carefully move the probe detector to locate the position of the first minimum

current. Record the 𝐼𝑚𝑖𝑛 1 and the postition as x1.


6. Carefully move the probe detector to locate the position of the first maximum

current. Record the 𝐼𝑚𝑎𝑥 2 and the postition as x2. And also the next minimum

current (𝐼𝑚𝑖𝑛 3) and the postition as x3.

7. Using the same procedure, do it for short circuit and horn antenna.

Measurement of Impedance (normalized)

Here is how to determine the load impedance by using the Smith Chart:

1. Determine the VSWR with a direct method;

2. Draw VSWR circle on the Smith Chart;

3. Point Q where r = 1/VSWR represents the input impedance of the load at electric

field minimum

4. Calculate the length of guide wavelength (𝜆𝑔) by the formula

𝜆𝑔 = 2(𝑥3𝑠𝑐 − 𝑥1𝑠𝑐)

5. The distance d of first electric field minimum from the load input is defined by

𝑑 = 𝑥1 = 𝑥3 − 𝑥3𝑠𝑐

6. Move 𝑑/𝜆𝑔 from the point Q .

7. Find the value of normalized load impedance.

---o0o---


Module 3

Amplitude Modulation

Modulation is the process of modifying the carrier signal to the information signal so that

the information signal can be transmitted properly. In general, modulation involves the modification

of the carrier signal having a frequency higher (bandpass signal) to changes in signal

characteristics messages from resources (baseband signal), carrier signal is referred to as the

modulated signal (modulated signal), while the message signal is referred to as modulation signal

(modulating signal). Demodulation is the reverse process of modulation, which is the process of

extracting the information signal from the baseband carrier signal so that the information can be

received, processed, and interpreted at the receiving end (also known as a sink).

Figure 3. 1. Ilustration of Modulation and demodulation process

Objectives

In this practical, you will learn some types of analog modulation, especially AM modulation. After

do this practical you are supposed to understand about:

Types and process of AM analog modulation.

AM signal demodulation

Fundamental Theory

Introduction Modulation Techniques

Modulation is a very important process in a communication system, particularly wireless

communication. Modulation is key among them because:


1. Modulation allows the antenna size becomes smaller, as the signal frequency becomes

higher. For an efficient radiation, measuring the size of the antenna should be λ / 10 or

more (ideally λ / 4), where λ is the wavelength of the signal to be radiated.

2. Modulation allows any technique or multiplex multiple paths so as to save resources

existing frequencies.

3. Modulation allows the channel assignment, for example in FM radio that separate radio

channels based on the frequency of the carrier signal. As an example for the RTC UI on

107.9 MHz, MBS at 102.2 MHz, 90.0 MHz Elshinta, and others.

A signal (carrier) can generally be expressed as:

tfAAtc ccc 2coscos)( (3.1)

where c (t) is the instantaneous wave function (instantaneous value), AC is the maximum

amplitude value [Volt], and cos θ is the angle that is divided into frequency components,

namely fc [Hertz] and phase components, namely φ [degrees ].

Based on the type of signal information, modulation is divided into analog

modulation in which a signal information in the form of analog signals and digital

modulation in which the information signal in the form of digital bits. The carrier signal is

always analog, because naturally a signal that can be transmitted in the air is an analog

signal. Based components of the equation, modulation is divided into amplitude

modulation (amplitude modulation, AM) and modulation angle (angle modulation). Angle

modulation itself subdivided based components, namely the frequency modulation

(frequency modulation, FM) and phase modulation (phase modulation, AM). AM

modulation AM then developed into a full carrier double side band (DSB-FC), double side

band suppressed carrier (DSB-SC), single side band (SSB), and vestigial side band

(VSB). Modulation FM and PM are divided by the width of the frequency spectrum owned

into a narrowband (NB) and wideband (WB).

Amplitude Modulation Process

At AM DSB-FC modulation, the carrier signal is :

tfVtv ccc 2cos)( (3.2)

While information signal is :


tfVtv mmm 2cos)( (3.3)

AM modulated signals generated by the equation:

tftfVVtV cmmcam 2cos2cos)( (3.4)

where tfVV mmc 2cos an envelope function equation and tfc2cos is a sinusoidal

wave equation. If the value of VC is issued, then the equation 2.4. can be written back

into:

v tftfmVtV cmAMcam 2cos2cos1)( (3.5)

where mAM is called as modulation index or mAM = Vm/VC. Modulation index determines the

quality of AM modulated signals. By using trigonometric identities:

v )cos(2

1)cos(

2

1))(cos(cos YXYXYX (3.6)

the AM modulated signal can be written as:

v tftfmVtfVtV mcAMcccam 2cos2cos2cos)( (3.7)

or if using the modulation index:

v tfftffmV

tfVtV mcmcAMc

ccam )(2cos)(2cos2

2cos)( (3.8)

Groove block diagram of AM modulated signal generation process shown in Figure 3.2.

Figure 3. 2. Block Diagram for AM Modulation


Figure 3. 3. Process AM modulation in the time domain proportionately and clear.

Figure 3. 4. Waveforms AM modulated signals proportional and clear.

The quality of signal modulation results can be seen from the indicators AM

modulation index. mAM modulation index values range between 0-1 or 0% - 100%, namely

1. mAM< 1 called under-modulated.

2. mAM = 1 called fully-modulated.

3. mAM> 1 called over-modulated.

In the over-modulated condition, there is an overlap phase in the envelope so the

recipient can not extract the information signal of the carrier signal due to signal distortion.

AM modulated signal waveform for different modulation index values shown in Figure 3.5.


Figure 3. 5. waveform signal modulated AM with modulation index values are different.

The quality of AM modulated signals can also be seen from the side of power

which must be seen in the frequency domain. To change the signal from the time

domain to the frequency domain, as you saw in the previous lecture, Fourier

transform method is used. Fourier transformation is used as the modulated signal

AM is considered as a signal that is continuous and has a certain period.

Wave equation in the equation 2.5 can be expressed in the expression of complex

numbers (exponential) to:

v tfjtgetgtv c

tfj

AMc

2exp)(Re)(Re)(2

(3.9)

where g (t) is the complex envelope function equation, namely:

v tfmVtg mAMc 2cos1)(

(3.10)

Then the Fourier transform, the frequency spectrum of the AM signal is:

v cccccAM ffMffffMffAfS 2

1)( (3.11)

where δ (f+fc) is a unit impulse function and M (f) is the spectrum of the message signal.

Figure 3.6. shows the spectrum of AM modulated signals where magnitude spectrum is a

function of the triangle. As seen, the spectrum of the AM signal consists of an impulse at

the frequency of the carrier signal with two doubles sideband spectrum message signal.

Sideband at a lower frequency called the lower sideband (LSB) and at a higher frequency

called the upper sideband (USB). Length of ribbon bandwidth (BW) of the AM signal is:

v mAM fB 2 (3.12)


Figure 3. 6. The form of the spectrum of AM modulated signals. (a). Message signal spectrum, (b) the spectrum of the AM signal.

Total power on AM signal can be calculated by using the principle of an average

sum of squares and by Parseval theorem. Total power in the AM signal is:

v )()(212

1 22tmtmAP cAM (3.13)

notation shows the average value. If the modulation signal m (t) = k cos (2πfmt), then

the equation 3:13. can be rewritten into:

v

211

2

1 22 k

PPAP cmcAM (3.14)

2

2

1cc AP is the carrier signal power, Pm is the power modulation signal m (t), and k is

the modulation index.

Total power on AM signal can be calculated also with the approach of the power

dissipated in the load resistance R. The power dissipated in the carrier signal is:

v

R

V

R

V

R

VP cccRMS

c2

2222

(3.15)

Power on each sideband with maximum amplitude

2

cAMUSBLSB

VmVV :


v

cAMcAM

cAM

USBLSB Pm

R

Vm

R

Vm

R

VPP

482

2

2

22

2

2

(3.16)

Overall power on AM signal DSB-FC is

v cAM

ccAM

cAM

cUSBLSBcTotal Pm

PPm

Pm

PPPPP244

222

(3.17)

21

2

AMcTotal

mPP (3.18)

In Equation 2.8, it appears there are three different frequency components,

namely:

1. tfV cc 2cos as a carrier that does not carry any information signal.

2. tffmV

mcAMc

)(2cos2

as lower sideband signals that carry information.

3. tffmV

mcAMc

)(2cos2

as upper sideband signals that carry information.

The presence of the three components of the frequency motivate the evolution of

the AM modulation techniques. Signal carrier that does not carry any information signal

having the greatest power based on the equation 2.14. and 2:18 so that its presence can

be suppressed. This raises the DSB technique suppressed carrier (DSB-SC) to reduce

wasted power. The second component of the signal sideband carries the same

information, but they occupy a wide bandwidth. This motivates the emergence of SSB

technique, in which only one sideband transmit information so as to reduce wasted power

and also reduces the use of bandwidhth too wide. SSB raises new problems when the

single sideband noise or distortion attacked throughout the course of transmission. No

back-up of information transmitted by SSB so appear VSB technique, where one

singleband have full power and the other has a lower power as a back-up information.


Figure 3. 7. Generation of SSB AM signal using (a) Filter SSB and (b) Balanced modulator which is a series of center-tapped transformers.

Balanced Modulator

A balanced modulator is used to generate a DSBSC signal. it suppresses the

carrier, leaving only the upper and lower sidebands which are the sum and difference

frequencies of the carrier and modulating signals respectively. The simplest form of a

balanced modulator is the diode ring or lattice modulator as shown in figure 3.8. Note that

both connections in (a) and (b) are identical; the configuration shown in (a) where the

diodes are arranged in a ring, shows how the name is derived

Figure 3.8 Balanced Modulator Circuit

The operation of the ring modulator is rather simple. The modulating signal is

applied to the input transformer, T1, while the carrier sine wave is applied to the center


taps of the input and output transformer. The carrier serves as a source of forward and

reverse bias for the diodes which function like swithces to conect the modulating signal to

the output transformer, T2. The result is that DSBSC signal will be generated at the output

transformer.

For ease in understanding, let us trace its operation though one cycle of the carrier

sine wave. When the carrier polarity is as shown in figure 3.9(a), diodes D1 and D2 are

forward biased, whereas diodes D3 and D4 are reversed biased. The forward biased

diodes conduct while the reverse biased diodes act like open circuits. The circuit may be

visualized as that in figure 3.9(b). Ignoring the modulating signal for the time being and if

the centre tap positions of the carrier oscillator are precise, the current that flows in the

upper part of the transformer primary winding at T2 and the current that flows in the lower

part of the transformer produce equal but opposite magnetic fields which cancel each

other and hence no current is induced in the secondary winding at T2;therefore, there is

zero output. This is how the carrier is suppressed in a balanced modulator. Now consider

the presence of a modulating signal. The modulating signal will appear across the

secondary winding of the transformer T1 and get conducted by diodes D1 and D2 to the

primary windings of transformer T2 which in turn induces an output at T2.

Figure 3.9 Simplified circuit Configuration during first half cycle of the carrier sine wave

When the carrier polarity is changed to that shown in Figure 3.10(a), diodes D3

and D4 are forward biased whereas diodes D1 and D2 are reverse biased. An equivalent

simplified connection is shown in figure 3.10(b). Similiarly, the modulating signal gets

conducted to the primary windings of transformer T2, but this time in the reverse direction

due to the connections of diodes D3 and D4. Hence the induced output at T2 is inverted.

The carrier remains suppressed at the output.


Figure 3.10 Simplified circuit Configuration during second half cycle of the carrier sine wave

The processes explained above repeat throughout the many carrier oscillations.

The result is a DSBSC signal the output as shown in figure 3.11. Observe the following

about DSBSC waveform

It is oscillating at the carrier frequency

Its envelope is not the shape of the modulating signal

A phase reverseal occurs at the time where the modulating signal crosses the

zero line

Figure 3.11 DSBSC Waveform generated in the ring modulator


Demodulation Process

AM demodulation process can be divided into::

1. Demodulation with Envelope or Non-Coherent

In the non-coherent demodulation, used detector casing (envelope). Sheath detector

consists of a step-up transformer to raise the voltage level, the diodes to rectify the

signal, and the RC filter.

Figure 3. 12. Detector Casing

The signal must be demodulated signal with the value of the modulation index m <1.

Here is a demodulation process..

Figure 3. 13. Demodulation Process Noh Coherent with m<1

If m> 1, there will be an exchange phase in the casing and cause distorted signal and

can not be interpreted on the receiver side.

Figure 3. 14. Demodulation Process Noh Coherent with m>1

.

2. Synchronous or Coherent Demodulation

In the synchronous demodulation, used a series of phase-locked loop (PLL) as a local

oscillator (LO). AM modulated signal into the demodulator circuit, then resurrected

from the LO signal corresponding to the desired carrier frequency. If the carrier

frequency according to the LO frequency, the signal will be filtered out and then

interpreted as signaling information. This principle is used in a conventional radio,


where you have to perform seek tuning or carrier frequency in accordance with twirling

LO knob on the radio.

Figure 3. 15. Demodulation Process Coherent with PLL

Equipment

No Component Quantity

1 53-100 RAT Measuring system 1

2 Amplitude Modulation Workboard 53-130 1

3 Computer set 1

Procedure

ATTENTION !!! Follow the instructions assistants in each experiment. Turn off RAT

Measurement System if you want to replace the board. Draw first the entire

waveform or spectrum signal and give signs as needed. Charging accreditation

forms will be given its own time. Perform the entire procedure of experiment with

time as efficiently as possible..

Amplitude Modulation

For analog modulation, Feedback software is used. General procedure for operating

Feedback software:

a. Starting to operate Feedback software:

1. From main menu, click toolbar: system → index

2. Choose the assignment according to the practical sheet

3. Choose the practical.

b. Ending the practical:


1. Click: System → end practical

2. If you want to end your practical in Feedback software, click: System → quit

ASSIGNMENT 1 PRACTICAL 1: Amplitude Modulation with Full Carrier

1. Set the <carrier level> to maximum

2. Set <modulation level> to zero

3. Note the signal at all monitoring points

4. Now increase the <modulation level> and observe at monitor point <6>

5. Increase the <modulation level> until the carrier amplitude just reaches zero on

negative modulation peak.

6. Observe the signals at all the monitoring points both with the oscilloscope and the

spectrum analyzer at various modulation levels.

Figure 3.16 Assignment 1 Practical 1 configurations

ASSIGNMENT 1 PRACTICAL 2: Demodulation using an Envelope Detector

Here the signal from the amplitude modulator from Assignment 1 Practical 1 is

demodulated using an envelope detector.

1. Select <Practical 2> from the <Practicals> menu in Assignment 1.

2. Set the <carrier level> to maximum.

3. Set the <modulation level>to about half scale.

4. Set the <time constant> to minimum.

5. Use the oscilloscope to monitor the detector output at monitor point <16> and adjust

the <time constant>.

6. Increase the time constant and note that the amplitude of the detected output.

7. Use the spectrum analyzer to observe the carrier component amplitude.

8. Compare the original modulating signal with the detector output in both shape and

phase at various time constants using the oscilloscope.



ASSIGNMENT 2 PRACTICAL 1: Double Sideband with Suppressed Carrier

1. Use the oscilloscope and spectrum analyzer to examine the signals at monitor point

<4> and <5>.

2. Set the <carrier balance> to mid-scale.

3. Examine at <6> and note the wave shape.

4. Use the spectrum analyzer to observe that there are two sidebands but no carrier.

5. Adjust the <carrier balance>.

6. Note the effect on carrier amplitude.

7. Adjust <modulation level> and <carrier level> and no the effect.

8. Monitor at <13> and adjust the <BFO Frequency> for stable trace, so that the BFO is

in phase with the original carrier.

9. Observe that the product detector output is the same as the modulating signal.


---o0o---


Module 4

Frequency Modulation

Objectives

In this practical, you will learn some types of analog modulation, especially FM modulation.

After do this practical you are supposed to understand about:

Types and process of FM analog modulation.

Differences between analog modulation of AM and FM

Fundamental Theory

Introduction

FM modulation is a modulation technique that is the most popular analog compared AM,

especially in the radio system applications. In the FM modulation, the amplitude of the carrier

signal is made constant, while the frequency of the carrier signal is varied to change the amplitude

of the information signal. Thus, the information on the FM modulation signal contained in the

component angle. This causes the FM has many advantages compared to AM, which are:

1. Immunity against noise on FM modulation is better than AM. It is caused by signals on the

information contained in the AM modulation amplitude and signal quality is strongly

influenced by the level of amplitude. Amplitude as known to be extremely susceptible to

noise, so we attacked signal noise and amplitude decreased, it is not impossible that the

transmitted information signal becomes distorted or lost altogether. FM signals are not

affected by variations in the amplitude of only using the amplitude threshold as a guide so

that FM is more resistant to atmospheric noise or impulses that can cause large

fluctuations in the amplitude of the signal. Threshold FM FM signal also causes more

resistant to noise burst.

2. FM allows the value of the quality of the measured signal as signal-to-noise ratio (SNR) for

the better, although FM occupies a wider bandwidth than AM.

3. The FM signal has a constant envelope so that the transmitted power more efficiently.

4. FM has a capture nature effect, whereby if there are two or more signals at the same

frequency into the FM receiver, then only the strongest signal to be received and other

signals will be rejected. This causes the FM is more resistant to co-channel interference

than AM will always receive all signals including the interference signal is weak.

Compared with AM, FM signal also has weakness include:


1. FM modulation require greater bandwidth than AM to generate capture effect and reduce

noise.

2. Equipment of FM transmitter and the receiver is far more complex than AM.

3. Reach FM signal closer than AM, because the frequencies used by FM higher so that the

wavelength is shorter than the AM signal which is longer so that it can be reflected through

the ionosphere to a more distant.

Modulation Process of FM

Suppose carrier signal is :

tωV=tv ccc cos (4.1)

FM signal basic equation is :

t+fπV=tv ccs frekuensideviasi 2cos (4.2)

wherein the frequency deviation depends on m (t). Frequency carrier signal will fluctuate, so that

the instantaneous carrier signal equation can be written as:

=tvs icicic φV=tπfV=tωV cos2coscos (4.3)

φi is the instantaneous angle tπf=tω ii 2 and fi is the instantaneous frequency.

Because tπf=φ ii 2 , then:

dt

dφ

π=fπf=

dt

dφ iii

i

2

1 atau 2 (4.4)

Based on the equation 4.4 it can be seen that the frequency is proportional to the rate of change

of the angle. If fc is carrier signal frequency and fm is message signal frequency, then:

dt

dφ

π=tωΔf+f=f i

mcci2

1cos (4.5)

cΔf is the peak frequency deviation of the carrier, ie mfc VkΔf with kf is a constant frequency

deviation sensitivity (Hz / volt) and Vm is the maximum amplitude of the message signal. Therefore,

obtained:

tωΔf+f=dt

dφ

πmcc

i cos2

1 (4.6)

then

tωπΔf+πf=dt

dφmcc

i cos22 (4.7)

To obtain the value of the angle, then the integration:


dttωπΔf+ω mcc cos2

(4.8)

We obtained:

m

mcci

ω

tωπΔf+tω=φ

sin2 (4.9)

tωf

Δf+tω=φ m

m

cci sin

(4.10)

Substituting equation 4.9. to equation 4.3., FM modulated signal obtained by the equation:

tω

f

Δf+tωV=tv m

m

cccs sincos

(4.11)

Comparison between m

c

f

Δf known as FM modulation index, namely:

m

c

f

Δf=β

pesansinyal frekuensi

pembawasinyal frekuensi puncakDeviasi (4.12)

FM modulated signal waveform can be seen in Figure 4.1.

Figure 4. 1. FM signal waveforms in the time domain..

Equation 4.11. can be expressed in a series of Bessel functions:

n=

mcncs tnω+ωβJV=tv cos

(4.13)


Figure 4. 2. Bessel functions for a particular order to the value of .

Jn()is a Bessel function of the first kind. With the expansion, is obtained

tJVtJV

tJVtJVtJVtv

mcmc

mcmcc

ff

mcc

ff

mcc

ff

mcc

ff

mcc

f

ccs

2Amp

2

2Amp

2

Amp

1

Amp

1

Amp

0

)2(cos)()2(cos)(

)(cos)()(cos)()(cos)()(

(4.14)

By using a Bessel function expansion, the frequency spectrum of the FM signal can be

obtained. In Figure 4.3. visible illustration of the frequency spectrum of the FM signal and shows

that the FM signal occupies a bandwidth wide enough compared with the AM signal.

Figure 4. 3. Illustration of the FM signal spectrum.

The value of each sideband magnitude can be seen in table Bessel functions for each

specific modulation index values as shown in Figure 4.4.


Figure 4. 4. Table Bessel functions for each particular value of the modulation index. .

Wide bandwidth FM signal can be calculated by Carson rule approach, namely:

mc ffBW 2 (4.15)

With this approach, because the length of the bandwidth of the FM signal is infinite. In the better

known term partner FM sideband than LSB and USB and bandwidth is not calculated from the LSB

to the USB.

FM signal with modulation index values are fairly small (β <0.3) referred to as narrowband

FM which only has 2 significant sideband pairs. While the FM signal with β> 0.3 will have more

than 2 significant sideband pairs and is referred to as wideband FM.

Processes on non linear FM so that the superposition principle can not be used. When the

message signal is a signal with a frequency much like the human voice or music, the analysis

becomes very complicated. In the calculation of the FM signal, has always assumed the message

signal is a single tone with the frequency used is the maximum frequency of the message signal.

Based on the equation 4.13., It can be seen that the maximum value of all components is

VcJn() for a number of n components. Note that for periodic sinusoidal signal, the value of the

average power is normalized or RMS 2

2

max )(2

RMSVV

, so that power for a number n of

components are:

2

)(

2

)(22

ncnc JVJV

(4.16)

Thus, the total power in the spectrum of the FM signal is:

n

ncT

JVP

2

))(( 2

(4.17)


Demodulation of FM

FM demodulation process is in the same principle as the AM demodulation process. Some

demodulation method is a tuned circuit (tuned circuit), Foster-Seeley Discriminator, and PLL.

Figure 4. 5. tuned circuit.

Figure 4.6 Foster-Seeley Discriminator Circuit.

Figure 4.7 Phase-locked loop Circuit.


Figure 4. 1. Modulator FM Amstrong.

Equipment


1 Arbitrary function generator AFG 3081 1

2 Dijital Storage Oscilloscope GDS-820C 1

3 Spectrum Analyzer GSP827 1

Spectrum Analyzer is a tool for the distribution of energy throughout spektrumfrekuensi

meyelidiki of an electrical signal known. From this investigation, obtained very valuable information

regarding the width of the field frequency (bandwidth), the signal power density, the effects of

various types of modulation, interference and signal generation as well as on all the benefits in the

planning and testing of RF circuits and pulse. Tool shown in the frequency domain is commonly

used for the analysis of electromagnetic signals at a certain frequency range, if there are sources

of interference on wireless devices, such as Wi-Fi and wireless router.

Procedure

ATTENTION !!! Follow the instructions assistants in each experiment. Turn off the

equipment if you want to replace the cable. Do not force the cable if the connector

does not fit or do not want to go! Note the instructions and labels on the equipment in

order to avoid the danger of electric shock.

Spectrum analyzer, Function Generator, and oscilloscope are used for FM practical

1. Make a carrier signal by: push MOD button, choose FM. Push waveform button, and choose the sinusoidal signal.

2. Set the carrier frequency by pushing FREQ/Rate button and insert the signal parameter that needed.

3. Set the signal amplitude by pushing AMPL button.


4. Make the information signal by: push MOD button, then choose FM button, and choose FM freq and insert the information signal parameter that needed. Then click return. (Information signal frequency 2 mHz – 20 kHz, default: 100 Hz)

5. Set the deviation by: choose Freq Dev and insert the value. (default: 100 Hz). Deviation Frequency is the peak deviation of frequency from a carrier wave and modulatede wave.

6. Observe the display of information signal and modulation signal on oscilloscope by linking the MOD terminal and MAIN terminal to the oscilloscope.

7. Observe the display of the modulation signal result on spectrum analyzer by connecting MAIN terminal to the spectrum analyzer.

Time Domain Analysis

1. Switch on the function generator and oscilloscope.

2. Using coaxial cable, connect the output from the function generator with the channel

from oscilloscope.

3. Set the frequency value of the carrier signal in function generator.

4. Set the frequency deviation in function generator.

5. Push <autoset> at oscilloscope to ease the observation automatically.

6. Observe the message signal and the modulated signal at the oscilloscope‟s monitor.

Frequency Domain Analysis

1. Switch on the function generator and spectrum analyzer.

2. Using coaxial cable, connect the output from the function generator with the channel

from oscilloscope.

3. Set the frequency value of the carrier signal in function generator.

4. Set the frequency deviation in function generator.

5. Adjust the frequency range of view in spectrum analyzer

6. Observe the spectrum of the signal

7. Analyze by using Bessel function and Carson Rule

---o0o---


Module 5

Telephony System

Telecommunications science are always trying to provide long-distance communications

services. These services can be private or open to public access. Modern telecommunication

services of the oldest and very commonly used is the telephone service. Layananan analog two-

wire telephone oldest is the public switched telephone network (PSTN) or plain old telephone

service (POTS).

Objectives

The assignment examines how a single telephone sends and receives signals in the telephone

system.

Understand about how analog telephone system works

Membuktikan adanya frekuensi tinggi dan rendah pada telepon keypad

Fundamental Theory

Introduction

This is a simplified circuit of the whole TELEPHONE to demonstrate the pirinciples of

operation. There are 3 circuits elements used : TELEPHONE, HANDSET and the LINE to the

switching centre.

Figure 5.1 Basic Telephony system

To build communication systems that succeed, in addition to the topology supported central

and good transmission line, also there must be procedures for call control are referred to as

signaling. On the phone there is a section that regulates signaling function, namely the switch hook,

keypad and allerter. The switch hook signaling process begins when you first lifted the telephone

receiver. Hook switch circuit functions are:


For signaling between the central and telephone

Disconnect Alerter and connect ot other telephone circuit

Figure 5. 1.Telphony System Circuit

Rotary Dia Phone

Figure 5. 2.Rotary dial phone circuit.

Hook switch serves to connect and disconnect the phone from the network. Into the

receiver there is an audio transducer, which is an electronic device that serves to convert sound

energy into electrical energy or vice versa. Audio transducer device is a microphone and Speaker

voice.

Microphone function convert acoustic signals into electrical signals through the diaphragm

contained him. Among these are the type of microphone in mikfofon dynamic, electric condenser,

ribbon, and a piezoelectric crystal microphone. The following is the construction of a dynamic

microphone.


Figure 5. 3.Construction of dynamic microphone.

Coil that moves on the principle of electromagnetic induction using a microphone that

converts sound waves into electrical signals. When sound waves hit a flexible diaphragm,

diaphragm will retreat to the back and respond in accordance with sound pressure occurs. This

pressure causes the coil moving in a magnetic field from a permanent magnet. The movement of

the coil in this magnetic field causes the voltage based on Faraday's law of induction. Rated

voltage is out of the coil is proportional to the pressure of sound waves which suppress the

diaphragm. In practice, also put an amplifier to increase the level of the incoming signal so more

easily processed. Impedance coil commonly used is about 8-16 ohms. Speaker sound working

principles contrary to the principle of the working microphone. Speaker sound is used to convert

electrical signals into sound waves. The following is the construction of Speaker sound.

Figure 5. 4.Construction of Speaker

On the phone type rotary dial used signaling with pulse dialing. In the signaling pulse

dialing, hook switch is pressed to dial the destination telephone number. If the 9 button is pressed,

then the hook switch will open and shut as much as 9 times as well as sending a signal pulse.

Advantages of this signaling is a system that is simple and inexpensive. However, you will feel the

sidetone (own voice through the speakers when speaking) and echo (the time lag between the

voice signal sent from the microphone to the sound reflection that goes to the speakers, so that it


appears like an echo).

Figure 5. 5. Graphic of Pulse Dialling Signaling

Telephone Touch Tone Dialling/Dual Tone Multi Frequency (DTMF)

In principle, this type of phone is not very different in the circuit of rotary dial phone, with

the only difference in the signaling system used. On a touch tone telephone system, used signaling

with dual tone multi-frequency (DTMF) where the phone number is pressed will be delivered as a

combination of two different frequencies.

(a) (b)

Figure 5. 6. System DTMF (a). Transmitter dan (b) Detector DTMF on receiver.

Signals are first amplified and separated by groups of high and low frequencies using a

lowpass filter (LP) and highpass filter (HP). Delimiter (L) is used to convert the tone separated into

waves boxes. Tone individually identified using 7 filters BP, where each filter missed a tone and

reject the other tone. Each filter is followed by a detector that will work when the input voltage has

reached a certain level. The detector output will generate a DC signal required by the switching

center to connect you with the dialed party.

Hybird Circuit of 2 Wire-4 Wire

Telephone hybrid circuit is a component on the customer side of a PSTN system that

serves to convert the two-wire system with four-wire systems to form a Bi-directional audio signal

path. In essence, the nature of the phone line are two audio signals move in two opposite


directions, which is the voice of the sender and receiver are moving together. Two signals are then

processed to move separately on the telephone transmission and switching systems that use a 4-

wire system. To change the phone signal on a two wire to four wire hybrid circuit is used to prevent

the mixing of two different sound signals. Nowadays, the modern phone system, use the line card

to the interface between analog channels so that the conversion takes place more efficiently. This

hybrid circuit also serves to amplify the signal and as an echo cancelers.

Figure 5. 7. Hybird Circuit on Telephony

Equipment

Equipment yang digunakan pada modul ini terdapat pada Tabel 5.2 berikut ini.

Tabel 5.2. Equipment yang digunakan pada Modul Sistem Teleponi.

No Nama Alat Jumlah

1. Telephone & Interface Workboard 58-110 1

2. 53-100 RAT Measuring system 2

3. Perangkat komputer 1

Procedure

ATTENTION !!! Follow the instructions of assistants in each experiment. Turn off the



order to avoid the danger of electrical shock.

USING FEEDBACK SOFTWARE Practical Instruction (done at the time of beginning using

software Feedback)

From the main menu to find out the tasks to be performed, click toolbar >> index. It will

show a collection of assignment.

Click the assignment you are doing


Then click the toolbar Practical accordance with the practical you are doing

To proceed to the next practical,

a. clicktoolbarSystem>>End practical

b. Then start over by clicking the next toolbarPractical.

ASSIGNMENT 1 PRACTICAL 1 : SWITCH HOOK

1. Press the button below the microphone handset,

2. Note the operation change-over switch and reading on the ammeter

ASSIGNMENT 1 PRACTICAL 2 : KEYPAD OPERATION

1. Switch the telephone to the „TONE‟ position

2. Keep the telephone Off Hook, and leave the line current control at the normal centre position

3. Press one button on the keypad. Observe the signal on the line, shown on the oscilloscope.

Keep the button pressed for this. Use the „options‟ menu to display the full screen oscilloscope

ASSIGNMENT 4 PRACTICAL 1 : KEYPAD CODES

1. Press the button on keypad

2. Observe the signals on the line

3. Observe the frequency of signal at the output of each filter

---o0o---


Module 6

Pulse Code Modulation and Time Division Multiplexing

Objectives

After following this lab, you are expected to:

Know the principles of conversion of analog to digital signals in PCM.

Recognize the multiplexing techniques based on time (TDM).

Fundamental Theory

Conversion of Analog to Digital Signal

Transmitted signals will decrease the quality. This degradation is caused by the existence

of things, among others:

Attenuation

Noise

Interference

To reduce these impact, the analog signals need to be converted to digital form, because it is

more resistant to noise and attenuation. The conversion of analog signals into digital form through

three stages of the process of sampling, quantization, and coding that all three are part of the

Pulse Code Modulation (PCM).

Sampling

Sampling is the process of measuring the amplitude of a continuous-time signal at discrete

instants. It converts a continuous-time signal to a discrete-time signal.Sampling frequency which is

usually used in the process of digitizing the voice signal is 8 KHz for digital telephony.

Mathematically this can be analogous to sampling as a result of multiplication (combining) signals

are sampled with a sampling signal. Here is a picture of the information signal, the signal wave

sample and sampling results:


Figure 6.1 Information Signal

Figure 6.2 Digital Signal

Figure 6.3 Signal Sampling Result

Quantization

Quantization represents the sampled values of the amplitude by a finite set of levels. It

converts a continuous-amplitude sample to a discrete-amplitude sample. In this quantizing

many comparator level is 2n where n is the number of bits used.

Figure 6.4 Quantizing


Coding

Coding designates each quantized level by a (binary) code. Here is a picture of

quantization and coding process:

Figure 6.5 Coding

Figure 6.6 Coding Result

Multiplexing

Figure 6.7. Application of Multiplexing in Fiber Optic

Multiplexing is a method of using a channel of communication together. Multiplexing is

intended to save resources from the communications channel. One form of multiplexing is the Time

Division Multiplexing (TDM).TDM is the time interleaving of samples from several sources so that

the information from these sources can be transmitted serially over a single communication


channel.In which one frame is divided into several time slots. Each time slot has the same period

and each frame has the same number of time slots, so each time slot on each channel talks

repeatedly at fixed intervals, so that TDM is a synchronous system. Time slots can be used by one

user to a channel talks. Other types of multiplexing are Frequency Division Multiplexing (FDM) and

Code Division Multiplexing (CDM).

.

Figure 6.8.Concept of Multiplexing.

Figure 6.9. Concept of frame and time slot in GSM-TDMA Communication System.

Multiplexing can be categorized into:

1. Frequency Division Multiplexing (FDM). This technique is the most popular and commonly

used on radio and TV transmissions. The frequency spectrum is divided into multiple

channels based on its frequencies.


Figure 6.10. FDM technique, (a). Signals with different frequencies, (b) signals superimposed

on a carrier signal with a higher frequency, and (c) the results of multiplexed signals.

1. Time Division Multiplexing (TDM). In this technique, the signal is transmitted on a same

medium with the same frequency, but its timing are different in each timeslot.

Figure 6.11. TDM technique.

2. Code Division Multiplexing (CDM). This technique divides timeslot based on different

codes. Usually a Walsh code.


Figure 6.12. Technical CDM.

3. Wavelength Division Multiplexing. This technique is used in fiber optic communications,

where each user slots are separated by wavelength different.

Figure 6.13. Techniques WDM.

Equipment

All experiments using TEKNIKIT FEEDBACK


1 53-100 RAT Measuring system 1

2 TDM & PCM Principles Mk 2 58-110 1

3 Personal Computer 1


Figure 6.14 TDM & PCM Principles Mk 2 58-110

You can change the frequency by using these properties

Figure 6.15 Frequency control for Oscilloscope 1

Procedure




order to avoid the danger of electrical shock..

USING FEEDBACK SOFTWARE Practical Instruction (done at the time of beginning using

software Feedback)


From the main menu to find out the tasks to be performed, click toolbar >> index. It will

show a collection of assignment.

Click the assignment you are doing

Then click the toolbar Practical accordance with the practical you are doing

To proceed to the next practical,

a. ClicktoolbarSystem>>End practical

b. Then start over by clicking the next toolbarPractical.

ASSIGNMENT 7 PRACTICAL 1 and 4: Basic Sampling and Aliasing Error

1. Follow the general instructions. click toolbar practical → basic sampling

2. Set frequency of oscilloscope 1 to approximately 800 Hz and output Vpp 2 volt. (Change

display size with a `menu option ').

3. Observe the waveform on the oscilloscope 1, the clock, the sampling wave (at test point 7)

and the output on the low pass filter. Analysis it!

4. Change the sample time by using the menu 'option' to ¼. Observe the waveform occurs.

Analysis it!

5. Repeat step 3 by changing the sample time into 1 / 8.

6. Repeat steps 1-3 for 500 and 2 kHz frequency.

7. Analysis the result

ASSIGNMENT 9 PRACTICAL 1 : Quantizing

1. Follow the general instructions. click toolbar practical → quantization

2. Set the voltage to 0 (zero) volt, using `DC Test Linear controllers' and recalibration to get

accurate results.

3. Set the input voltage to 1 V, observe the digital output.

4. Repeat for 2 V and a maximum voltage untill the digital display does not change. Observe

the digital output.

5. Repeat to -1 V and -2 V and to a minimum. Observe the code changes' at zero voltage.

6. Analysis!

ASSIGNMENT 9 PRACTICAL2 : Quantizing Noise

1. Follow the general instructions. click toolbar practical → quantization noise

2. Set the frequency at 300 Hz and voltage amplitude (peak) at 0.2 volts by using the

controller `Fine control '.

3. Set the resolution to 4 bits, by using the menu 'Option ".

4. Observe the digital output (test point 7) and the results of the output filter (test point 8)

5. Repeat for different bits of resolution.

6. Use the 'spectrum analyzer' to see the output


7. Analysis!

ASSIGNMENT 9 PRACTICAL1 : Introduction of Multiplexing

1. Follow the general instructions. click toolbar practical→introduction to multiplexing

2. Observe the output on the oscillator 4 which is a result of demultiplexing (test point 7) and

output filters.

3. Compare the form of waves (test point 14) by using a large display. set oscillator 1 to 0

(zero) volt and varying the amplitude to determine the time slots used by each signal.

4. Increase the output value of oscillator 1.

5. Compare the input waveforms for each oscillator with output wave by using the menu

`option 'to choose a time slot.

---o0o---


Module 7

Digital Modulation

Modulation is the process of laying the information to the carrier frequency signal having a

frequency higher. In general, the resources in the form of analog signals. To streamline the

transmission of the digital modulation must be in the form of digital information. The digital

modulation is actually a process of varying the characteristics and properties of the carrier wave

(carrier) such that the form of the result has the characteristics of bit (0 or 1) it contains.

Things become a big problem in the transmission of information when the transmitter and

receiver are separated by a free space, in which a signal transmitter signals sent will experience

distortion and noise, causing errors in the information to be received. The digital communication

system is used to minimize the effects that occur in the channel, maximizing transfer rate, and the

accuracy of the information transmission.

The advantages of digital communication systems:

1. The occurrence of interference is very small;

2. Resistant to noise;

3. Can correcting the error;

4. Easy to manipulate;

5. Easy for processing and multiplexing.

The disadvantages of digital communication systems:

1. Requires a system of higher demand;

2. Requires additional fee for converting analog to digital systems.

Objectives

To know the type of digital modulation techniques

Understand ASK, FSK and PSK modulation

Undersand the digital demodulation

Fundamental Theory

Introductory of Digital Communication


Analog-to-

Digital

Converter

Source

Encoder

Encryption

and

Scrambling

Channel

Encoder

Line

Coder

Digital

Modulation

DemodulatorChannel

Decoder

Baseband

Processing

Source

Decoder

Digital-to-

Analog

Converter

Line

Decoder

Signal

Regeneration

CH

AN

NE

L

SUMBER

SINYAL INFORMASI

(ANALOG)

PENERIMA

SINYAL INFORMASI

(ANALOG)

Baseband Transmission

Carrier TransmissionW

ireless

Wireline

Wire

less

Wireline

Analog

Waveform

Analog

Waveform

Digital Data

Digital Data

PENGIRIM

PENERIMA

Antena

Transmitter (Tx)

Antena

Receiver (Rx)

Figure 7.1. Block Diagram of Digital Communication.

a. Information Source

Information source can be a continuous signal or discrete signals. In digital communication,

analog signals should be converted into the digital one using Analog to Digital Converter (ADC).

b. Source Encoder and Decoder

Source coding is used to code information source in order to make information more suitable

for being transmitted. Source encoder will reduce the number of bit needed for transmitting

some kinds of information. This technique will reduce the bandwidth needed. Source decoder

is used to decode information after signals received in the receiver.

c. Line Coding and Decoding

Line coding applies digital data format without using modulation technique. The requirements

of line coding are spectrum at low frequency, transmission bandwidth required, timing content,

error monitoring, and code efficiency. The examples of line coding are Non Return to Zero

(NRZ), Return to Zero (RZ), Manchester, Alternate Mark Inversion (AMI), HDB3, etc.

d. Encryption and Scrambling

Two main reasons for using encryption and scrambling are confidentiality and authentication.

e. Channel Coding dan Decoding

In high speed data transmission, the „1‟ and „0‟ are usually of very short duration. Channel

coding and decoding is applied for reducing bit errors that are caused by the noisy channel.


Channel coding process data stream to make it compatible with channel characteristic. The

technique is applied by adding some parity bits to the digital word.

f. Digital Carrier Modulator and Demodulator

The main purpose of digital modulator is to map binary information into signal waveforms in

order to make the binary information capable to be transmitted over the channel.

g. Communication Channel

Communication channel is any medium that is used to transmit signals from transmitter to

receiver. In practice, the channel is noisy and will disturb signals.

Bandpass Transmission System

Bandpass transmission system is a transmission system that has undergone modulation,

ie the information signal (discrete) modulates the carrier signal (continuous). Before modulated

using a digital modulation technique, the signal must be in the form of digital data information.

Therefore, the information signal is still analog form must first be converted using an ADC (Analog

to Digital Converter). There are a wide variety of digital modulation techniques include ASK

(Amplitude shifted Keying), FSK (Frequency shifted Keying) and PSK (Phase shifted Keying). Also

known modulation techniques QAM (Quadrature Amplitude Modulation) which is a combination of

ASK and PSK.

Amplitude Shift Keying (ASK)

Amplitude Shift Keying (ASK) is digital modulation technique represented by amplitude level of the

information. In ASK, binary information, such as 0 and 1, will be stated as a different amplitude

level. In a band pass ASK, the signal is represented by:

(1)

Figure 7.2. ASK modulated Digital signal


There are two kinds of demodulation and detection schemes for ASK: no coherent (asynchronous)

and coherent (synchronous).

Frequency Shift Keying (FSK)

In frequency shift keying, the frequency of the carrier varies with the baseband information. For

example, binary 0 will have carrier frequency f1 while binary 1 will have carrier frequency f2. The

modulated signal for binary FSK is formulated by :

(2)

Figure 7.3. FSK modulated Digital signal

FSK signals can be demodulated and detected by using both non coherent technique and coherent

technique.

Phase Shift Keying

Phase Shift Keying (PSK) is digital modulation technique that using different phase carrier

according to the binary information.

Figure 7.4. PSK modulated Digital signal

Equipment



1. DCS-B VLSI Based Digital Communication Training

System

1

2. Oscilloscope 1

3. Passive Probe Detector 1

Procedure





General procedure for operating Feedback software:

Amplitude Shift Keying (ASK)

1. Select the group 4 (GP4) clock in the Clock Generation section with the help of switch

S1 and observe the corresponding LED indication.

2. Set the data pattern S4 using switch as per the given worksheet and observe the 8-bit

data pattern at SDATA post.

3. Connect SIN3 post to the IN2 post and IN3 post to the Ground in carrier modulation

section.

4. Connect SDATA to IN16 post and TXCLK to CLK2 post of the Encoded Data section.

5. Select NRZ-L data with the help of the switch S3 and observe the corresponding LED

indication in the Encoded Data section.

6. Connect OUT10 post of the Encoded Data section to IN4 post as a control input for the

carrier modulator section.

7. Observe the ASK modulated signal at the OUT2 post of the Carrier modulation section.

8. For the demodulation, connect the OUT2 post of the carrier modulator to the IN24 post

of the ASK demodulator section.

9. Observe the ASK demodulated data at the OUT20 post of the Carrier ASK

demodulator section.

10. Verify the recovered data with the SDATA.


Frequency Shift Keying





3. Connect SIN1 post to the IN3 post and SIN3 post to the IN2 in carrier modulation

section.






7. Observe the FSK modulated signal at the OUT2 post of the Carrier modulation section.


of the FSK demodulator section.

9. Observe the FSK demodulated data at the OUT24 post of the Carrier ASK



Frequency Shift Keying





3. Connect SIN2 post to the IN2 post and SIN3 post to the IN3 in carrier modulation

section.







7. Observe the PSK modulated signal at the OUT2 post of the Carrier modulation section.


of the PSK demodulator section.

9. Observe the PSK demodulated data at the OUT27 post of the Carrier ASK



---o0o---


Module 8

Digital Line Coding

Objectives

Understand the baseband transmission

Understand NRZ and AMI Encoding and Decoding

Fundamental Theory

An Overview of Baseband Transmission

Baseband refers to the signal that has a very narrow frequency range. Almost all sources of

information generate baseband signals. Baseband signals are transmitted without modulation, that

is, without any shift in the range of frequencies of the signal.

Figure 8.1. Baseband Transmission System

Line Coding

A line code defines the relationship between the binary signal at the source and the

corresponding sequence of symbol elements transmitted over the channel. A line code provides

the transmitted symbol sequence with the necessary properties to ensure reliable baseband

transmission and error free detection at receiver. To achive this, the following characteristic have to

be considered:

Spectrum at low frequency

Transmission bandwidth required

Timing content


Error monitoring

Code Efficiency

Type of Line Coding

a. Non-Return-to-Zero (NRZ) signal are the easiest formats that can be regenerated. These

signal don‟t return to zero with the clock. Using NRZ, logic 1 bit is sent as a high value and

logic 0 bit is sent as low value. NRZ can be divided into some type:

Non-Return to zero – LEVEL (NRZ-L)

Non-Return to zero – MARK (NRZ-M)

Non-Return to zero – SPACE (NRZ-S)

Figure 8.2. Non-Return to Zero

b. Return-to-Zero

With RZ codes, the signal level representing bit value „1‟ lasts for the first half of the bit

interval T, after which the signal returns to reference „0‟ level for the remaining half of the

interval. A „0‟ indicate by no change, with the signal remaining at the reference level „0‟.

c. Biphase Level Coding (Biphase-L)

Popularly known as Manchester Coding. With the Biphase-L, „one‟ is represented by half

wide pulse, positioned during the first half of the bit interval and a „zero‟ is represented by a

half bit wide pulse positioned during the second half of the bit interval.

d. Alternate Mark Inversion (AMI)

In AMI, binary data are coded with three amplitude levels, 0 and ±A. Binary „0‟s (space) are

always coded as zero level, while binary „1‟s (marks) are alternately coded as +A and -A.

The transmitted symbol rate is the same as the binary data rate, and there is no dc

component in symbol stream.


Figure 8.3. Various Line Decoding Scheme

Line decoding

The decoding scheme of line coding can be listed as follows:

The waveform A is the result of line coding techniques.

After passing down the cable, the original waveform A is attenuated and the clear

transition have become indistinct, as shown in waveform B.

To counteract the distortion of waveform B, the system includes an equalizer, which

„sharpens‟ the received signal (waveform C).

Passing this equalized waveform through a threshold detector (waveform D) has the result

of regenerating a binary signal very similar to transmitted one.

Retiming is needed to prevent irregularities (jitter) in waveform D. A regenerated clock

(waveform E) are processed with the output D in the retiming circuit to produce a

regenerate signal (waveform F) which can be an almost perfect replica of the transmitted

signal.

Figure 8.4. Line Decoding


Equipment Equipment


1. DCS-B VLSI Based Digital Communication Training

System

1

2. Oscilloscope 1

3. Passive Probe Detector 1

Procedure





Line Coding NRZ-L, NRZ-M, NRZ-S, BIO-M






4. Selection of different encoded data‟s are done using switch S3 and observe the

corresponding LED indication.

5. Connect OUT10 post of the Encoded Data section to IN27 post of Decoded Data.

6. Observe the recovered clock at REC.CLK2 and decoded data at OUT24 post of

Decoded Data section


AMI Encoding and Decoding






4. Observe the AMI encoded data at the OUT11 post of the Encoded Data section.

5. Connect OUT11 post of the Encoded Data section to IN26 post of Decoded Data and

OUT 10 post of Encoded Data to IN27 post of Decoded Data section.

6. Select BIO-M data using Switch S3 and observe the corresponding LED indication.

7. Observe the decoded AMI data at the OUT22 post od Decoded Data section

---o0o---


Module 9

Finite Impulse Response Filter

Objectives

Understand the DSP and its applications

Understand the concept of FIR filters and design FIR filter

Fundamental Theory

Overview of DSK

DSK TMS320C6713 is one of the types C6000 that can work on a fixed-point or floating-

point. However, DSP is still a starter kit, which is a platform that can simulate DSP C6713. This

type is intended for educational purposes, research, and evaluation. However, the results of the

application that we created in the DSK type is very likely to apply to the actual C6713 DSP.

Texas Instruments publish a series of DSP board for applications DSP processors with low

cost, one of which is a series of DSK TMS320C6713 DSP board. Basically, this board was

developed as a low-cost platform that has high performance to facilitate learning for all about digital

signal processing. On the DSP board is already integrated components that related with signal

processing using DSP (Digital Signal Processor). Components of board is hardware, but can be

programmed using Code Composer Studio software. In Figure 1 and Figure 2 respectively display

DSK TMS320C6713 and the block diagram of DSK TMS320C6713.

Figure 9.1. Display DSK TMS320C6713


Figure 9.2. Block diagram of DSK TMS320C6713

The main components as well as supporters of the DSK TMS320C6713 include:

Processor TMS320C6713

It is a processor with a clock speed of 225 Hz which support the operation of fixed-point

and floating-point. Operating speed can reach 1350 million floating-point operations per

second (Mflops) and 1800 million instructions per second (MIPS). In addition, the

processor is able to perform 450 million multiply-accumulate operations per second.

CPLD (Complex Programmable Logic Device)

CPLD contains registers that serves to regulate the features that exist on the board. On

the DSK C6713, there are 4 types of CPLD registers, namely:

1. USER_REG, Register to set switches and LEDs as desired by users.

2. DC_REG, Register to monitor and control the daughter card.

3. VERSION Register for indications that related to the version of the board and CPLD.

4. MISC Register to manage other functions on the board.

Flash memory

DSK uses flash memory to booting. In the flash contains a small program that called POST

(Power On Self Test). This program is run when DSK was first on. POST program will

examine the basic board functions as a USB connection, audio codec, LEDs, switches,

and so on.

SDRAM

The main memory that serves as a repository of instructions and data.

AIC23 Codec

Serves as ADC and DAC for the incoming signal to the board.

Daughter card interface

Additional connectors are useful for developing applications on board. There are three

connectors, namely memory expansion, peripheral expansion, and Host Port Interface.

LEDs and Switches


LEDs and switches is a feature that can help in building applications because can be

programmed as desired by the user.

JTAG (Joint Test Action Group)

Is a connector that can transfer data at very high speeds. This will be useful in real-time

applications.

DSK can be used for many things, ranging from communication simulation, control system

to image and sound processing. DSP commonly used in communications applications (mobile).

Embedded DSP can be found in cellular phones, fax / modems, disk drives, radios, printers,

hearing aids (hearing aids), MP3 player, high-definition television (HDTV), digital cameras and

others. The use of DSP in many tools can reduce the price of production, because the DSP can be

programmed according to the needs, the softaware is cheap and sufficient hardware support.

Digital Filters

The digital filter is a mathematical procedure or algorithm that processes the digital input

signal and generates a digital output signal that has certain properties in accordance with the

purpose of the filter. This filter can use in many applications. Most of the signal processing

applications using filters. In PSD, the filter that designed is digital filter. Digital filter can be divided

into two IIR Digital Filters (infinite impulse response) and FIR (finite impulse response). This

division is based on impulse response filter. FIR has a finite impulse response length, whereas IIR

infinite. FIR not has pole, then the stability can be guaranteed, while IIR has poles so more

unstable. In the high-order digital filter, error that happen because rounding the filter coefficients

can cause instability.

Some of the advantages of digital filter than analog filter is:

1. The digital filter has a linear phase response.

2. Because it was built based on a mathematical procedure using the software, the digital

filter performance is not easily affected by environmental conditions.

3. Response digital filter easily adapted to the needs by changing the mathematical

procedure only.

4. The digital filter can process many different signals with only one making it more efficient

algorithms.

5. The digital filter can be used for very low frequencies.

The digital filter weakness compared to the analog filter is:

1. Speed filter performance is highly dependent on the operating system and the processor

used and the level of difficulty of the algorithm.


2. In the application on the analog signal, before being put to the digital filter, the information

signal must be converted first into a digital signal that uses additional devices such as ADC

that will add to costs and affect the performance of the filter.

3. The design of the digital filter requires special skills in programming and others.

In general:

a. Finite Impulse Response (FIR)

Formula FIR can be seen as follows:

)()()(1

0

knxkhnyN

k

(1)

b. Infinite Impulse Response (IIR)

IIR formula can be seen as follows:

0

)()()(k

knxkhny (2)

The basic operation that used in signal processing just a simple multiplication and

summation. However, these two operations are performed is very numerous, so to implement in

the application is required a very fast processor to perform mathematical calculations. So,

designed a microprocessor that works specifically for digital signal processing called the Digital

Signal Processor (DSP).

Stage filter design can be seen in the following flow chart

Filter Specifications

Figure 9.3. Filter Specification.

Passband is an area where the desired frequency is passed, while the stopband is an area

where the undesired frequencies is attenuated (attenuated power to almost nothing magnitude). In


both these areas there is usually a ripple with the ripple deviation δp and δs deviation passband

ripple in the stopband. Transition region is an area where occurs a change between passband and

stopband. In the design of the filter is always used normalized frequency, thus facilitating the

design.

Calculation of filter coefficients can be done by several methods, namely windowing,

optimal method, and the method of counting frequency. In this module only discussed windowing

method for calculating the filter coefficients.

On the principle of windowing method, it is stated that if a function has limited functionality

(non-periodic) in the frequency domain, then the function will not be limited (periodic) in the time

domain and vice versa. Because the filter is limited to a certain frequency, then in the time domain

filter function is infinite. This is certainly contrary to our desire to design a filter with a length of h [n]

is limited. To limit the length of the filter in the time domain with a boundary called a window.

Nevertheless, the effect is to restrict the filter in the time domain, frequency domain then the length

of the filter becomes infinite.

FIR Filter

FIR filter serves to operate a real-time digital filter on a DSP. Named "finite" or limited

because there is no feedback on the type of filter. There is no feedback because the value of a

signal sample is limited to the value of (N-1) so that the number of samples depends on the

number of coefficients N. On the TMS320C6713 DSK, the use of FIR filters include the use of the

ADC and DAC are integrated with the DSP board. ADC serves to capture and transform the signal

into discrete form, whereas the DAC function transform back into an analog signal.

In general, an FIR is defined by the impulse responses, h(n), where h(n) is filter

coefficients as found in Figure 3. The value and number of filter coefficients are determined by the

desired filter specifications. Manually a value and the number of filter coefficients can be searched

using a variety of methods that exploit the concept of discrete Fourier transform and windowing

techniques.

Figure 9.4 FIR Filter

with bi is the value of filter coefficients and q is number of filter coefficients.


Equipment

In practical to this module used such tools in Table below.

Table Equipment used in Module Digital Modulation


1 DSK TMS320C6713 1

2 Software MATLAB 1

4 Software Code Composer Studio 1

5 Microphone 1

6 Audio Speaker 1

Procedure

ATTENTION !!! Always follow the instructions of lab assistant !! Do not store set-ups

because it will remove the default data !!! Be careful in doing targetting because if it

fails, it will undermine the entire system. Shrink speaker because the frequency used

is quite noisy. Be careful in operating equipment with a smooth board and press the

buttons if required.

In general, this experiment using MATLAB Simulink software and integrated with CCS

studio so it can be programmed on the TMS320C6713 DSK. The above process is called as the

targeting process. For digital filter design is done in Simulink with the help of FDA Tool.

Targetting Simulink in the DSK TMS320C6713

Simply, the targeting process used SIMULINK ® and CCS. To connect SIMULINK with

DSK needed ® Real Time Workshop, Embedded Target for TI C6000 DSP, and Link for CCS.

These three things can be found in SIMULINK ® and must be done configuration settings. The

third relationship that can be seen in the figure below.

In Figure 2 below show the process of debugging and verification conducted by the CCS

software. The use of CCS allows to generate codes that will be used in the DSP C6000 so that no

need programming manually because it was done by the CCS

Figure 9.5 Flowchart of targetting in DSK C6000

Design of Filters


Designing Filters use the help of Filter Design and Analysis (FDA) tool that found in

MATLAB software. The results from the use of this tool will be obtained FIR filter coefficients

required specifications. In this design, used methods Blackman.

Specification of Digital Filter design:

Low Pass Filter

Sampling Frequency (fs) = 16 000 Hz

Cut off Frequency (fs) = 3000 Hz

Transition Width = 1000

In this design method is used Blackman

f = transition width / sampling frequency

= 1000 Hz/16000Hz

= 0.0625

The number of coefficients

(N) = 3.3 / f

= 3.3 / 0.0625

= 53

Furthermore, the number of coefficients will be entered into the FDA tool.

Practical Procedures

By using the filter specifications such as the example above, then the steps to create a

filter is as follows: (Assistant MUST accompany)

1. Open the Simulink file FIR.mdl. Then, DSK connect with a computer, Perform diagnostics and

enable the studio CCS program when there is no alarm;

2. Then open the block FDA Tool in FIR.mdl (available 3 blocks FDA tool where each FDA tool will

be controlled by a single button on the DSK). In Figure 3 beside, display the simulation FIR filter


3. Fill in the desired filter specifications on the display are simulated as in below;

Figure 9.6 Input simulation parameters

4. Perform targetting from Simulink to DSK TMS320C6713 by pressing the incremental build as

contained in Figure 5 below. Remember DO NOT SAVE IN;

Figure 9.7 Display icon to perform targetting

5. Connect the Line in DSK with output on the computer, and Line Out DSK on the computer

microphone input. Connect the headphones on DSK with Loudspeaker;

6. Open the file 44100.wav that will serve as an input audio signal. This file is generated signal at a

frequency of 100-7000 Hz;

7. Open the file spectrumliat.mdl and run it;

8. Press the DIP switch on the DSK to see the results of the filters;

9. Fill borang observations and perform the above steps to design a filter with the specifications

given by the assistant then. In the process of targeting the experimentalist must be

accompanied by an assistant.

---o0o---


Module 10

Radio Lines Simulation Using Radiomobile Software

Objectives

To understand concept of wireless communication.

Learning to simulate one or more radio lines with modified parameters using Radio

Mobile software.

Fundamental Theory

Radio waves which propagating on the air will experience several different

physical phenomena, such as reflection, transmission, diffraction and scattering.

Propagation environment is the geographical environment in which radio waves

propagate from transmitter to receiver. Propagation environments strongly influenced by

the physical parameters such as pressure, temperature, humidity, refractive index,

topography, vegetation distribution, roads, and buildings. Radio wave propagation can be

determined by modeling the different physical mechanisms, such as damping vacuum,

atmospheric attenuation, attenuation due to vegetation, and others.

The simplest radio propagation is line-of-sight. Microwave signals can be blocked

by buildings or valleys. The waves must avoid any obstacles or tilt on the earth to make

transmission. If the position between the building is blocked, it is necessary to put an

antenna tower higher, in order to remain in a position to "see each other" (line of sight). In

general, the propagation is called line-of-sight if there are no waves diffraction effects, this

means that there is no obstacles in first Fresnel ellipsoid. In Figure 7.1 below shown a

simple model of radio propagation path analysis line-of-sight.

Figure 10.1 Simple Radio Line Propagation


In Figure 10.1, the power losses vacuum propagation (free space loss) can be calculated

by equation 1. below

v MHzkmdB FDFSPL log20log2045,32 (1)

If the loss of the transmission line, LT and LS, in Figure 9.1 is ignored, then the received

power receiver is:

vL

G

rGPP R

TTR

2

4

(2)

Radio Mobile Software

The first step to create a wireless system is to make a design and simulation of the

system. One of the tools to design and simulate a wireless system is the software Radio

Mobile. Radio Mobile is a software developed byRoger Coude for amateur radio users.

Radio Mobile using digital terrainelevation model for the calculation of the coverage

and signal strengthreceived at various points along the radio path. Radio Mobile

automaticallybuilds a profile between two points on a digital map showing the

coverage area and first Fresnel zone. During the simulation, the software will check the

line-of-sight and calculate the path loss. By using Radio Mobile, it is possible to make a

network of several different topologies, including network master/slave, point-to-multipoint.

This software can be used to calculate the coverage area of a base station in a point-to-

multipoint, working for a system that has frequency of 100 kHz to 200 GHz.

Equipment


1. Radio Mobile Software 1

2. Computer 1

Procedure

ATTENTION !!! Always follow the instructions of lab assistant !! Do not store set-ups

because it will remove the default data !!!!

Point-to-Point Radio System

1. Open Radio Mobile software (rmweng.exe);

2. Open the Folder Properties (F8), select the name of the city with. Select a city name or enter a position (lattitude and longitude) of the city and select the size of the image (Size height);

3. Open the Network properties (ctrl N), then open System. Make the desired system.

Set the parameters of the system;


4. Open unit properties (ctrl U), place the appropriate unit desired location; 5. Open the Network properties, and open membership, specify the system used for

each unit; 6. To display all units on the map, click View, then click Show network, and the click

All. 7. Calculate the link budget for the link by clicking Tools, then click the radio link (F2).

It can also display the details of the simulation output. (Tools → Radio → link →

view details) 8. Change parameters, such as antenna height, the unit being TX . RX. Give your

analysis! Repeater on Point-to-Multi Point Radio System

1. Open Radio Mobile software (rmweng.exe);

2. Open the Folder Properties (F8), select the name of the city with . Select a city name or enter a position (lattitude and longitude) of the city and select the size of the image (Size height);

3. Open the Network properties (ctrl N), and open the Parameters. Make the desired

parameters. Set the parameters of the parameter;

4. Select System. Create two systems (repeaters and hand held) is desired. Set the parameters of the parameter;

5. Select Membership. For repeater:

•Select Command on Role of Repeater table; •Repeater on System. For Hand held: •Select Subordinate on Role of Repeater table; •Hand held on System.

6. Click Tools, select Coverage, select Find best site 7. Give your analysis!

---o0o---


REFERENCES

Akademika Digital Communication Training System Experiment and Service

Manual

Christopher Haslett, Essentials of radio wave propagation, Cambridge University

Press, 2008 052187565X pages 119-120

Demetrius T Paris and F. Kenneth Hurd, Basic Electromagnetic Theory, McGraw

Hill, New York 1969 ISBN -0 048470-8, Chapter 8

George W. Hutchson, John K.H. Leong, Lim Choon Kwee, Nah Cherng Kai.

“Communication Principles and Systems”. School pof Engineering, Temasek

Polytechnic, Singapore.

H. P. Westman et al., (ed), Reference Data for Radio Engineers, Fifth Edition,

1968, Howard W. Sams and Co., no ISBN, Library of Congress Card No. 43-

14665 page 26-1

Manual Feedback Microwave Trainer MWT530

Shanmugam, Sam. “Digital Analog Communication Systems”. John Wiley & Sons,

Inc. Canada. 1979.

Stuart M. Wentworth. Fundamentals of Electromagnetics with Engineering

Aplications.Wiley.2005

TEKNIKIT Telephony Training System Student‟s Workbook 58-001WB

William H.Hyat and John A.Buck. Elektromagnetika, 7th ed. Erlangga. 2006

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