1. ELECTRONICS COMMUNICATIONS(EKT313)
Lecturers : 1.Pn Sahadah binti Ahmad
2.Dr.Mohd Fareq bin Malek
3. Pn Sharifah Zarihan (PLV)
Contact #: /
/04 985 /

2. EKT313 Sem: 1 2011/2012 Meeting: Lecture 3 Hours @ DK
Lab 2 Hours / 2
MKR 3 & MKY 7
Attendance are compulsory!!

3. Course Outcomes (CO)
CO1: Ability to utilize software and simulation tools in designing
systems in communications . 
CO2: Ability to analyze transmission of the signal through
channels, noise and modulation. 
CO3: Ability to identify, analyze and design the architecture of
radio frequency , amplifiers, mixers, AM and FM
modulators and demodulators, transmitter circuits and
receiver circuits.
 CO4: Ability to perform measurement, analyze output signal
and trouble shoot using laboratory equipments /
instruments.

4. SYNOPSIS
OBJECTIVES:
This subject introduces the students about the design and electronics used in communication system. This includes the design and architecture of radio frequency amplifiers, mixers, AM and FM modulators and demodulators, transmitter circuits and receiver’s circuits. It is also to give introduction to students about how to analyze circuit and its importance in communication electronic field.

5. SYNOPSIS TOPICS COVERED ARE:
Introductions to Electronics Communications,
AM& SSB Modulations & AM Circuits,
FM and FM Circuits,
Radio Transmitter and
Communications Receivers
Transmission Lines

6. SYNOPSIS Practical: Software : ADS 2009
Designing and constructing of Radio Frequency (RF) Receiver architecture, i.e. modulator, demodulator, oscillator, filters, down converters, etc using software and hardwares.
Software : ADS 2009

7. ASSESSMENTS Final exam = 50% Test 1 & 2 = 20% Lab = 30%
5% presentation
5% Report
20% Project

8. List of text books and references
[1] Louis E. Frenzel Jr, Principles of Electronic Communication Systems , 3rd Ed., McGrawHill (text)
[2] Wayne Tomasi, Electronics Communication Systems, Prentice Hall
[3] Paul Young, Electronics Communications Techniques,

9. REVIEW TO COMMUNICATION SYSTEMS PART 1
LECTURE 1
REVIEW TO COMMUNICATION SYSTEMS
PART 1

10. of COMMUNICATION SYSTEM?
WHAT DO YOU UNDERSTAND of
COMMUNICATION SYSTEM?

11. DEFINITIONS OF COMMUNICATIONS
Humans exchanging information
Machines exchanging information
Conveying thoughts, feelings, ideas, and facts
Sending and receiving information by electronic means

12. BARRIERS TO COMMUNICATIONS
Language: human, computer, or electronic
Distance: space between sending and receiving parties

13. COMMON FORMS OF COMMUNICATIONS
Human voice: face-to-face conversations, public speakers, actors in plays, etc.
Audio: CDs, tape, records, radio
Body language: non-verbal
Print: newspapers, magazines, books, etc.
Film: still and movie
Video: movies, graphics and animation
Music: personal, concerts

14. FORMS OF ELECTRONIC COMMUNICATIONS
Radio and TV broadcasting
Telephone, wired and wireless
Fax
Pagers
Computer networks: modem, , Internet and World Wide Web, wireless
Satellites, radar, radio telescopes

16. MODEL OF ALL COMMUNICATIONS SYSTEMS
Transmitter
Receiver
Channel TX RX
Communications
medium
Noise
Received
information
Information to be
transmitted

17. Model of all communication systems

18. Basic components:  Transmitter  Channel or medium  Receiver
 Noise degrades or interferes with transmitted information.

19. Communication Systems
Transmitter
The transmitter is a collection of electronic components and circuits that converts the electrical signal into a signal suitable for transmission over a given medium.
Transmitters are made up of oscillators, amplifiers, tuned circuits and filters, modulators, frequency mixers, frequency synthesizers, and other circuits.

20. Communication Systems
Communication Channel
The communication channel is the medium by which the electronic signal is sent from one place to another.
Types of media include
Electrical conductors
Optical media
Free space
System-specific media (e.g., water is the medium for sonar).

21. Communication Systems
Receivers
A receiver is a collection of electronic components and circuits that accepts the transmitted message from the channel and converts it back into a form understandable by humans.
Receivers contain amplifiers, oscillators, mixers, tuned circuits and filters, and a demodulator or detector that recovers the original intelligence signal from the modulated carrier

22. Communication Systems
Transceivers
A transceiver is an electronic unit that incorporates circuits that both send and receive signals.
Examples are:
Telephones
Fax machines
Handheld CB radios
Cell phones
Computer modems

23. Communication Systems
Noise
Noise is random, undesirable electronic energy that enters the communication system via the communicating medium and interferes with the transmitted message.

24. TYPES OF COMMUNICATIONSTX
Channel RX
Simplex:
One-way
Duplex:
Two-way
Half duplex:
Alternate TX/RX
Full duplex:
Simultaneous
TX/RX TX RX
Channel(s) TX RX

25. TYPES OF COMMUNICATIONS SIGNALS
Analog - smooth and continuous voltage variation.
Digital - binary or two voltage levels.
Time

26. COMMUNICATIONS SIGNAL VARIATIONS
Baseband - The original information signal such as audio, video, or computer data. Can be analog or digital.
Broadband - The baseband signal modulates or modifies a carrier signal, which is usually a sine wave at a frequency much higher than the baseband signal.

27. MODULATION
An electronic technique in which a baseband information signal modifies a carrier signal (usually a sine wave) for the purpose of frequency translation and carrying the information signal via radio.
The common types of modulation are amplitude, frequency and phase.

28. Modulation at the transmitter

29. AMPLITUDE MODULATION
The modulating (baseband) signal is a sinusoid in this example.
High-frequency carrier

30. An AM signal as it usually appears on an oscilloscope
The carrier frequency is normally much
higher than the baseband frequency.

31. FREQUENCY MODULATION
The baseband signal controls the carrier’s frequency and the carrier’s amplitude remains constant.

32. FM Resting fc Increasing fc Decreasing fc Increasing fc Resting fc
Modulating signal
Carrier

33. MULTIPLEXING
Multiplexing (MUX or MPX) - the process of simultaneously transmitting two or more baseband information signals over a single communications channel.
Demultiplexing (DEMUX or DMPX) - the process of recovering the individual baseband signals from the multiplexed signal.

34. MULTIPLEXING AND DEMULTIPLEXING
Single communications channel (radio or cable)
MUX
DEMUX
Recovered baseband
information signals
Original baseband
information signals

35. Modulation and Multiplexing

37. ELECTRONIC COMMUNICATIONS APPLICATIONS
Radio broadcasting (AM & FM)
Television broadcasting (analog & DTV)
Cable TV
Wireless remote control
Paging
Navigation and direction finding
Telemetry

38. ELECTRONIC COMMUNICATIONS APPLICATIONS (Continued)
Radio astronomy
Surveillance
RF identification (ID)
Music services
Telephones (wired, cordless, cellular)
Facsimile
Two-way radio

39. ELECTRONIC COMMUNICATIONS APPLICATIONS (Continued)
Radar
Sonar
Amateur radio
Citizens and family radio
Data communications
Networks
Internet and World Wide Web

40. FREQUENCY AND WAVELENGTH
Cycle - One complete occurrence of a repeating wave (periodic signal) such as one positive and one negative alternation of a sine wave.
Frequency - the number of cycles of a signal that occur in one second.
Period - the time distance between two similar points on a periodic wave.
Wavelength - the distance traveled by an electromagnetic (radio) wave during one period.

41. PERIOD AND FREQUENCY COMPARED
T = One period
time
One cycle
Frequency = f = 1/T

42. Frequency and wavelength compared+ T
time
f = 1/T 
distance

43. CALCULATING WAVELENGTH AND FREQUENCY
 = wavelength in meters
f = frequency in MHz

44. THE ELECTROMAGNETIC SPECTRUM FROM 30 HZ TO 300 GHZ
Wavelength
( = 300/f)
107 m
106 m
105 m
104 m
103 m
102 m
10-1 m
10-2 m
10-3 m
10-4 m
10 m
1 m
Millimeter
waves
ELF VF
VLF LF MF HF
VHF
UHF
SHF
EHF
30 Hz
3 kHz
300 Hz
30 kHz
3 MHz
3 GHz
300 kHz
30 MHz
30 GHz
300 MHz
300 GHz
(f = 300/)
Frequency

45. LOW AND MEDIUM FREQUENCIES
Extremely Low Frequencies - 30 to 300 Hz
Voice Frequencies to 3000 Hz
Very Low Frequencies - 3 kHz to 30 kHz
Low Frequencies - 30 kHz to 300 kHz
Medium Frequencies kHz to 3 MHz

46. HIGH FREQUENCIES High Frequencies - 3 MHz to 30 MHz
Very High Frequencies
- 30 MHz to 300 MHz
Ultra High Frequencies
- 300 MHz to 3 GHz
(1 GHz and above = microwaves)
Super High Frequencies
- 3 GHz to 30 GHz
Extremely High Frequencies
- 30 GHz to 300 GHz

47. THE ELECTROMAGNETIC SPECTRUM ABOVE 300 GHZ
Wavelength
0.8 x 10-6 m
0.4 x 10-6 m
10-3 m
10-4 m
10-5 m
Millimeter
waves
Ultraviolet
Infrared
X-rays
Visible
Gamma rays
Cosmic rays
300 GHz

48. OPTICAL FREQUENCIES Infrared - 0.7 to 10 micron
Visible light to 0.8 micron
Ultraviolet - Shorter than 0.4 micron
Note: A micron is one millionth of a meter. Light waves are measured and expressed in wavelength rather than frequency.

49. Noise, interference and distortion
Noise:unwanted signals that coincide with the desired signals. Noise is random, undesirable electric energy.
Two type of noise:internal and external noise.
Internal noise: Caused by internal devices/components in the circuits.
External noise:noise that is generated outside the circuit. Eg: atmospheric noise,solar noise, cosmic noise, man made noise.
Interference-one type of external noise
Distortion: signal being distorted

50. Limitations in communication system
Physical constraint
-Delay, attenuation, bandwidth limitation, etc
Technological constraint
hardware.
Expertise
- economy, law

51. Frequency Spectrum &Bandwidth
The frequency spectrum of a waveform consists of all frequencies contained in the waveform and their amplitudes plotted in the frequency domain.
The bandwidth of a frequency spectrum is the range of of frequencies contained in the spectrum.It is calculated by subtracting the lowest frequency from the highest.

52. Frequency Spectrum &Bandwidth (cont’d)
Bandwidth of the information signal equals to the difference between the highest and lowest frequency contained in the signal.
Similarly, bandwidth of communication channel is the difference between the highest and lowest frequency that the channel allow to pass through it

53. At this stage you should be able to: ● Explain the functions of the three main parts of an electronic communication system. ● Describe the system used to classify different types of electronic communication and list example of each type. ● Discuss the role of modulation and multiplexing in facilitating signal transmission.