Download 1 Course: PHY 411 – Electronics communication theory I (2 Credits

Course: PHY 411 – Electronics communication theory I (2 Credits – Compulsory)
Course Duration: Two hours per week for 15 weeks (30 hours), as taught in 2015/2016 session.
Lecturer:
Yusuf A.
B.Sc, M.Sc (Ilorin)
Department of Physics Electronics and Earth Sciences
College of Natural and Applied Sciences
Fountain University, Osogbo, Nigeria.
E- mail: [email protected]
Consultation Hour: Wednesday 2 – 3pm
COURSE DETAILS
Basic concept of communication systems, channel and users. Introduction to transmission medium,
signal and system analysis. Fourier series, fourier transforms, high input impedance circuiyts. High
frequency oscillators. Modulations and detection. Amplitude modulation: switching modular, envelope
dectector, double side-band suppressed carried (DSBSC) modulation, generation of balanced modular,
ring modulation coherent detector of DSBSC waves, Double balanced modulation, single side-band
modulation (SSB) and demodulator. Vestigial side-band modulation (VSB), comparision of AM systems,
frequency and phase modulation. Wide band and marrow bone FM, AM, and FM discriminators,
sampling principles, theorems and techniques. Pulse modulation. PAM, PWM and PCM.
Course Description
The course deals with the basic concept of communication systems, channel and users. Double balanced
modulation, single band modulation (SSB) and demodulator will be taught intensively. Wide band and
marrow bone FM, AM, and FM discriminators, sampling principles, theorems and techniques, Pulse
modulation, PAM, PWM and PCM will also be discussed.
Course justification
The course is carefully selected to give the students the general view of basic concept of communication
system. Modulation, Wide band and marrow bone FM, AM, and FM discriminators, sampling principles,
theorems and techniques, Pulse modulation, PAM, PWM and PCM will also be discussed.
Course Objective
The main objective of the course is to impact on students the knowledge of electronic communication
theory.
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Course Requirements
This is a core course for all final year students in the Department of physics electronics and Earth
sciences. Students are expected to attend normal classes and participate in robust database during the
course of the programme. Students will be expected to carry out assignments. They are expected to
attend 75% of classes before they can sit for the examination. All students will have E-mail accounts. It is
compulsory for all students to contribute to the online discussion group and to submit their assignments
in word processed form.
Methods of Grading
S/N
1
2
3
4
5
Type of Grading
Participation in class
Assignments
Test
Final examination
Total
Score (%)
10
10
10
70
100
Course Delivery Strategies
Face to face lecture will be the major method of course delivery while class discussion, group work will
be complimentary. Basic lecture notes will be provided to the students.
LECTURE CONTENT
Week 1 and 2: Evolution of Electrical communication
Objective: At the end of the lectures, students will have an overview of the course; describe the various
definitions, concepts and terminologies associated with electric communication.
Description:
First Hour (week 1)
Overview of the course
Second Hour (week 1)
Definition of terminologies and concepts of communication
First Hour (week 2)
Basic concept of communication system
Second Hour (week 2)
2
Element of communication system.
Study Questions
1. What is communication system?
2. List the element of communication system.
3. Differentiate between analogue and digital information source.
Reading List:
1. Electronic communication system 4th Edition.
2. Electronic communications 4th Edition.
Week 3 and 4: Radio transmitter and superheterodyne receiver, signal and Fourier analysis
Objective: Students are expected to be able to explain the physics behind the working of a radio
transmitter and superheterodyne receiver. They will be expected to have full understanding of signal
analysis using the Fourier analysis.
Description:
First Hour (week 3)
The working of Radio transmitter
Second Hour (week 3)
The working of superheterodyne receiver
First Hour (week 4)
Signal analysis
Second Hour (week 4)
Fourier analysis
Study Questions
1. Briefly explain the element of communication system.
2. Write short note on signal as used in communication
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3. A signal f(t) is defined by the expression
4;
f(t) = �
−4;
0 ≤ 𝑡𝑡 ≤ 3
3 ≤ 𝑡𝑡 ≤ 6
Sketch the signal and determine its period.
4.
A periodic signal f(t) is given by the expression
f(t) = t/2;
0 ≤ t ≤ 2π
Determine the Fourier series of the signal.
Reading List:
1. Electronic communication system 4th Edition.
2. Electronic communications 4th Edition.
Week 5 and 6: Fourier analysis, modulation, amplitude modulation systems, average power for
sinusoidal AM
Objective: At the end of the lectures, Students will have an understanding of amplitude modulation
systems.
Description:
First Hour (week 5)
Examples on Fourier analysis
Second Hour (week 5)
Modulation
First Hour (week 6)
Amplitude modulation systems
Second Hour (week 6)
Average power for sinusoidal AM
Study Questions
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1. What is modulation?
2. Explain the importance of modulation in communication world.
3. With the aid of equations and diagrams, explain how amplitude is modulated in Amplitude
Modulation (AM) system.
Reading List:
1. Electronic communication system 4th Edition.
2. Electronic communications 4th Edition.
Week 7 and 8: Double-sideband Suppressed Carrier (DSBSC), mixer circuits, amplitude demodulator
circuits.
Objective: At the end of the lectures, Students are expected to know what Double-sideband Suppressed
Carrier (DSBSC), mixer circuits, amplitude demodulator circuits are all about.
Description:
First Hour (week 7)
Introduction to Double-sideband Suppressed Carrier (DSBSC)
Second Hour (week 7)
Double-sideband Suppressed Carrier (DSBSC)
First Hour (week 8)
Mixer circuits
Second Hour (week 8)
Amplitude demodulator
Study Questions
1. What is Double-sideband Suppressed Carrier (DSBSC) band modulation?
2. What are mixers? Briefly explain the operation of one of them.
3. An envelope modulated signal is defined by
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e (t) = [10 + 3cos (2π x 103t)] cos (2π x 107t)
Obtain amplitude and frequency of the unmodulated carrier.
Reading List:
1. Electronic communication system 4th Edition.
2. Electronic communications 4th Edition.
Week 9: Test and review of test Questions.
Objective: To administer a test towards continuous assessment at the end of which test questions will
be reviewed and discussed with the students.
Description:
First Hour (week 9)
Administration Test
Second Hour (week 9)
Review and discussion of Test Questions
Week 10: Single- side band Modulation, balanced modulator and SSB generator.
Objective: At the end of the lectures, Students will be able to define and explain Single- side band
Modulation and balanced modulator.
Description:
First Hour (week 10)
Single- side band Modulation
Second Hour (week 10)
Balanced modulator and SSB generator
Study Questions
1. What is Single- sideband Modulation?
2. An envelope modulated signal is defined by
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e (t) = [10 + 3cos (2π x 103t)] cos (2π x 107t)
(i) Determine the modulation index and the modulating frequency.
(ii) If the power of the carrier is 100W, calculate the power in the two sidebands and the total
power in the carrier.
Reading List:
1. Electronic communication system 4th Edition.
2. Electronic communications 4th Edition.
Week 11: Angle modulation and frequency modulation (FM)
Objective: At the end of the lectures, Students will be able to discuss the angle modulation and
frequency modulation (FM)
Description:
First Hour (week 11)
Angle modulation
Second Hour (week 11)
Frequency modulation (FM)
Study Questions
1. How can one use Angle Modulation (AM) to produce Frequency Modulation (FM) and
Phase Modulation (PM) system.
2. An FM signal is given by
e(t) = 12 sin (4 x 108t + 9 sin 4 x 104t)
Calculate the carrier and the modulating frequency.
Reading List:
1. Electronic communication system 4th Edition.
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2. Electronic communications 4th Edition.
Week 12: Frequency spectrum for Sinusoidal FM, average power in sinusoidal FM
Objective: At the end of the lectures, Students will be able to discuss frequency spectrum for Sinusoidal
FM and average power in sinusoidal FM.
.
Description:
First Hour (week 12)
Frequency spectrum for Sinusoidal FM
Second Hour (week 12)
Average power in sinusoidal FM
Study Questions
1. With the aid of diagrams only show the difference between AM, FM and PM.
2. An FM signal is given by
e(t) = 12 sin (4 x 108t + 9 sin 4 x 104t)
(ii) Obtain the modulation index and the frequency deviation.
(iii) What mean power will be dissipated in an 8Ω resistive load.
Reading List:
1. Electronic communication system 4th Edition.
2. Electronic communications 4th Edition.
Week 13: Phase modulation and Pulse modulation
Objective: At the end of the lectures, Students will be able to explain Phase modulation and Pulse
modulation.
Description:
First Hour (week 13)
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Phase modulation
Second Hour (week 13)
Pulse modulation
Study Questions
1. An angle modulated signal
e (t) = 10cos (108πt + 3 sin 2 x 103t) is present across a 50-ohm resistive ;oad. Determine:
(a) the total average power
(b) the peak phase deviation
(c) the peak frequency deviation
Reading List:
1. Electronic communication system 4th Edition.
2. Electronic communications 4th Edition.
Week 14 and 15: Revision Exercise
Objective: These two weeks are specifically left for revision of all the topics and subtopics covered
during the course. Students are required to ask any question related to the course while the lecturer will
also ask the students questions to determine the level of understanding of the course.
Revision Questions
1. A given AM broadcast station transmits a total power of 50kw and uses a modulation index
of 0.707. Calculate
(a) the carrier power.
(b) the transmission efficiency.
(c) the peak amplitude of the carrier input if the antenna is represented by a 100Ω resistive
load.
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2. For a diode mixer, the b coefficient is 0.03s/v, the peak oscillator voltage is 10mV and the peak signal
voltage is 1Mv. The transfer impedence of the output circuit at IF is 1000Ω. Determine the peak output
voltage at IF.
3. A sinusoidal carrier has am amplitude of 10V and frequency 30KHZ. It is amplitude modulated by a
sinusoidal voltage of amplitude 3V and frequency 1000HZ. Plot accurately to scale the modulated
waveform,showing two complete cycles of the modulating wave and determine the modulation index.
4. Why is it important in AM broadcast transmission to prevent 100% modulation depth being
exceeded? Describe the trapezoidal method for mointoring such transmissions.
5. A standard AM transmission sinusoidally modulated to a depth of 30%, produces side frequencies of
4.928 and 4.914mHZ. The amplitude of each side frequency is 75V. Determine the amplitude and
frequency of the carrier.
6. Define the term modulation index as applied to an amplitude modulated wave.
7. Explain in words how the information signal is recovered from an SSB carrier by a demodulator circuit.
8. Modulating frequencies of 0.5, 0.2 and 2.5KHZ are applied to an SSB modulator using a carrier
frequency of 100KHZ.
(a) Sketch the spectrum of the output signal, noting the positions of the three modulating frequencies, if
the modulator is set for USB modulation
(b) Repeat (a) for LSB modulation
(c) comment on the order of modulating signal frequencies in the two side bands.
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