To the woman who continually electrifies my once boring life… To my students who compelled me how to learn for the sake of teaching… To my baby who always regenerates my strength whenever I’m heavily attenuated… And to Him that gave us Maxwell, Hertz, Faraday, Marconi, Tesla, Gauss, Fessenden, etc… To Him is the kingdom, the power, and the glory forever…
“He that walketh with wise men shall be wise” Proverbs 13:20
Self-Sufficient Guide to Electronic Communications Engineering by Jason M. Ampoloquio copyright 2005 All rights reserved.
No part of this book may be reproduced in any form or by any means, electronic, or mechanical including photocopying, recording, mimeographing, or by any information and retrieval system, without the written permission from the copyright holder.
ISBN 971-92592-7-2
Printed in the Philippines
Important Legal Information: Warning and Disclaimer
This review book presents the fundamentals of Communications Engineering using modified concepts, principles, and examples from common textbook and reference materials in the field of Communications Engineering. While the author/compiler believes that the concepts and data in this book are accurate, correct and meticulously prepared, the materials in this book is intended solely as a quick reference aid, and is not represented to be an appropriate or safe solution to pass the ECE licensure exam. For this reason, the author makes no warranties, express or implied, that the concepts, examples, and data contained in this book are free from errors. I would, however, appreciate readers bringing to my attention any errors that may appear in the printed version of this book for reasons beyond my control. These errors and any other comments can be communicated to me by e-mail addressed to:
[email protected]
The Author Jason M. Ampoloquio, PECE PECE consultant – Beta Electric Corporation Senior System Analyst, Department of Finance (Insurance Commission) Mobile/Web Application Developer Faculty Member – University of Santo Tomas President, Powerful Review Center MSECE Major in DSP-De La Salle University (units earned) BSECE-Central Colleges of the Philippines HR Reyes Scholar Coach, IECEP Quizzers Champion: 1. ECE Quiz Show (1999) 2. 1st Brain Encounter (1998) 3. Physics Quiz Show (1996) 4. Mathematics Wizard (1996) 5. Inter Engineering Quiz Show (1995) Battle of the Brain School Representative (RPN-9) Quizzer-19th and 20th IECEP Quiz Show Author: 1. Electronics Engineering SUPERBook 2. EST Refresher 3. Mathematics Refresher 4. GEAS Refresher 5. Electronics Refresher EST Review Director Former Faculty: TUP-M, CCP Resource Speaker, Various Topics in Communications In-house reviewer, Various Colleges and Universities Sought after reviewer in Communications Engineering
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Although it is a relatively easy process to select a book from a catalog or shelf in a bookstore, the actual effort involved in its preparation and publication can be quite complex and can extend over a significant period of time (for this book I personally experienced almost 2 years of hundreds of revision, an average of eight hrs every night for searching, researching, reading, comparing, computing, analyzing, and typing—3 hrs of which is allocated for drawings and illustrations). As a beginner, I realized that the creation of a written work is a team effort requiring the cooperation and assistance of many persons. Thus, I would be remiss if I did not thank those who made this book possible. First & foremost, to God for His indescribable gift. To my parents Jayme Ampoloquio and Teresita Ampoloquio, to my sisters and brothers namely Elizabeth, Ma. Teresa, Dennis, and Emmanuel, to whom I owe one of my deepest appreciations. To all the people who in invaluable ways help to mold my character as a teacher and a reviewer namely Dean Cynthia Llanes & Carlos Llanes, and Leonardo Samaniego. To my fellows, Engrs. Anthony Lopos, Gerard Ang, Rufino Orpia, Reginaldo Marinay, Dennis Paus. And to the following: Vic Buenconsejo (Colegio de San Agustin Bacolod) and Dean Christopher Taclobos (UNO-R Bacolod) for their continuous trust in my potentials and warmth accommodation during my stay in their respective places. To Engr. Reynante Abuyan: Thank you for lending me your awesome printer and editing the first few chapters of this superb guidebook. To all ECE reviewees: Thank you for your patronage and trust! And may all your dreams be electric! To Engrs. Randel Espina of Ateneo de Davao, Neil Abalajon of TUP-Visayas, Marlon Lagulos of Univ. of Southeastern Philippines, Carlos Sison of PLM, Nieves Elarco of SLPC, Dean Jose Magleo of Collegio de Dagupan, Evelyn Raguindin of Adamson University, Dean Roman Palo of Holy Angel University, Engr Oliver Mariano of Bulacan State University, and to those people whom I cannot individually write their names. I sincerely thank you all… jma/pece
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or as much as many have tried to create a good ECE guide book, it seems good to me also, having had a fine understanding to finally craft a review book intended not to compete to those which are existing but in my own little way and with God’s help, to properly guide ECE students on their quest to the elusive licensure examination.
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he Self-sufficient Guide to Electronic Communications Engineering (ECE) that I preferred to call SUPERBook, is a comprehensive and meticulous compilation of modified concepts in every aspect of communications engineering discipline. The SUPERBook is carefully scrutinized to cover important details that are imperative to board exam preparation but also taken into account minute pieces of information commonly neglected by reviewees that lead to occasionally guessing the board exam questions.
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ince it is also a proven fact that 50% of learning process comes from visual aids and illustration, and past ECE board questions require the knowledge of block diagram to be answered correctly, the author/compiler painstakingly prepared lavish illustration that will scintillate the interest of readers.
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lso the SUPERBook flagships is its minefield of 250+ scrupulously solved and 2100+ multiple choice practice problems aimed to help ECE reviewees to keep abreast to the recent trend of ECE board examination. he answer to even-numbered questions are intentionally withheld by the author/compiler but will be discuss to EXPERTS reviewees during review, refresher and coaching program for the reason that the author is anticipating ECE school teachers and co-reviewers will use some of the question as a safe and quick exam references since the answers are withheld and encourage readers to test their knowledge in the field of communications engineering.
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nd finally, the author/compiler firmly believed that knowledge is cumulative. It is not based on each person’s re-inventing that is known, but rather accumulating what has been learned from the past, synthesizing new ideas from old formulas and principles, and creating completely new insights, I hope elements of all three can be found in these pages, and I want to acknowledge the contribution of all those works (textbooks, journals, manuals, magazine, and website tutorials) has added to my understanding of the various topics of this lavish guidebook. Read it till it Hertz… Happy reading… c”,) Jason M. Ampoloquio, PECE
Contents Title page Dedication Acknowledgments Preface CHAPTER 1: Introduction to Electronic Communication Section 1. Basic Principles of Communications Engineering Section 2. Amplitude Modulation Section 3. Angle Modulation Section 4. Noise Analysis and dB Calculations Section 5. Transmitters and Receivers
1-xx 1-1 1-38 1-68 1-94 1-125
CHAPTER 2: Acoustics & Broadcasting Section 6. Acoustics Fundamentals Section 7. Television Fundamentals Section 8. AM, FM AND TV Broadcasting Standards Section 9. Microphones & Loudspeakers
2-xx 2-1 2-28 2-69 2-89
CHAPTER 3: Wire Communications Section 10. Transmission Lines and Waveguides Section 11. Fiber Optics Communications Section 12. Telephone Networks and System Section 13. Facsimile Transmission
3-xx 3-1 3-50 3-106 3-159
CHAPTER 4: Computer Communications Section 14. Pulse Modulation Section 15. Digital Communications Section 16. Data Communications
4-xx 4-1 4-19 4-55
CHAPTER 5: Wireless Communications Section 17. Antenna Fundamentals Section 18. Radio-Wave Propagation Section 19. Microwave Engineering Section 20. Satellite Communications Section 21. Cellular Communication System
5-xx 5-1 5-42 5-62 5-86 5-113
CHAPTER 6: Navigational Aids Section 22. Navigation System Section 23. Radar Fundamentals
6-xx 6-1 6-29
CHAPTER 7: Miscellaneous Topics Section 24. Laws & Ethics Section 25. Basic Signals & System
7-xx 7-1 7-41
PRC Examinee’s Guide Answers to Odd-Numbered Questions Study Tips Major References Author’s Page
8-xx 9-xx
Section 1 Basic Principles of Communications Engineering
PLSB =
m 2Pc 4
PUSB =
PLSB =
m 2Pc 4
PUSB = 0
PLSB =
m 2Pc 4
PUSB = 0
m 2Pc 4
Section 2 Amplitude Modulation Section 3 Angle Modulation Section 4 Noise Analysis and dB Calculations Section 5 Transmitters & Receivers
Introduction to Electronics Communication
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Section
Basic Principles of
1
Communications Engineering
1-1
Read it till it Hertz!
Electronic Communication is the transmission, reception, and processing of information between two or more locations using electronic circuits.
DEFINITION.
Allocation: Entry in the Table of Frequency Allocations of a given frequency band for the purpose of its use by one or more terrestrial or space radio communication services or the radio astronomy service under specified conditions.
DEFINITION.
Allotment: Entry of a designated frequency channel in the agreed plan, adopted by the ITU, for use by one or more nations for a terrestrial or space radio communication services in one or more identified countries or geographic areas and under specified conditions.
DEFINITION.
DEFINITION. Assignment: Authorization given by a nation for a radio station to use a radio-frequency channel under specified conditions.
HISTORICAL PERSPECTIVE 1820
Hans Christian Oersted discovered the relation between electricity and magnetism, later known as electromagnetism.
1821
Andre Marie Ampere already observed momentarily the phenomenon we now call electromagnetic induction and hypothesized the existence of magnetic field around a current-carrying conductor.
1822
Michael Faraday discovered electromagnetic induction, the reverse of Oersted discovery.
1830
An American, Joseph Henry, demonstrated telecommand by sending an electronic current over one mile of wire to activate an electromagnet which caused a bell to strike, thus wire telegraphy was born. Samuel F.B. Morse, successfully exploited Henry’s invention commercially.
1866
James Clerk Maxwell put together the principles of Oersted, Faraday and hypothesized the existence of electromagnetic waves.
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BASIC PRINCIPLES OF COMMUNICATIONS Engineering
1-2
1886
German physicist, Heinrich Hertz performed an experiment on spark gap transmission verifying Maxwell statement. Hertz experimentally showed the existence of such waves which he called radio waves that paved the way for wireless communication.
1896
An Italian, Guglielmo Marconi developed the first wireless telegraph and successfully sent a message over a distance of few kilometers using a spark gap transmitter.
1900
Reginald Aubrey Fessenden, invented AM and successfully transmits a few words using spark gap transmitter.
1936
Major Edwin Armstrong developed the first successful FM radio system.
A. .NOMENCLATURE OF RADIO FREQUENCY BAND.
Based on ITU-R Recommendations V.431-6 Frequency Range 0.03 0.3 3 30 300 3 30 300 3 30 300 3 30 300 3 30 300
to to to to to to to to to to to to to to to to to
0.3 3 30 300 3400 30 300 3000 30 300 3000 30 300 3000 30 300 3000
Hz Hz Hz Hz Hz kHz kHz kHz MHz MHz MHz GHz GHz GHz THz THz THz
Metric Subdivision
Adjectival Designation
Gigametric Hectomegametric Decamegametric Megametric Hectokilometric Myriametric kilometric Hectometric Decametric metric decimetric centimetric millimetric decimillimetric centimillimetric Micrometric Decimicrometric
ELF ELF ELF ELF ULF (Voice) VLF LF MF HF VHF UHF SHF EHF EHF EHF EHF EHF
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1-3
B. .ELEMENTS OF BASIC COMMUNICATIONS SYSTEM.
1.
Transmitter A collection of electronic components and circuits designed to convert the information or intelligence into a signal suitable for transmission over a given communication medium.
2.
Channel The medium by which the electronic/electromagnetic signal is sent from one place to another. 2 General Categories i.
Wire Medium The signal is confined within the proximity of the channel or medium.
ii.
Wireless Medium The signal is not subjected to limits, boundaries, or channel restrictions.
a.k.a. Bounded or Guided medium
a.k.a. Unbounded or Unguided Medium Noise Noise is a random, undesirable electrical energy that enters the communications system and interferes with the transmitted message. 3.
Receiver The receiver is another collection of electronic components and circuits that accept the transmitted message from the channel and convert it back into a form understandable by humans.
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BASIC PRINCIPLES OF COMMUNICATIONS Engineering
1-4
Read it till it Hertz…jma Noise SPECTRUM ª
White Noise - White noise is defined as a noise that has equal amount of energy per frequency.
This means that if you could measure the amount of white noise energy between 100 Hz and 200 Hz it would equal the amount of energy between 1000 Hz and 1100 Hz. ª
Pink Noise - Pink noise is noise that has an equal amount of energy
per octave.
This means that pink noise would have equal power in the frequency range from 40 to 60 Hz as in the band from 4000 to 6000 Hz. ª
Brown noise - Brown noise is similar to pink noise, but with a power
density decrease of 6 dB per octave with increasing frequency (density proportional to 1/f2) over a frequency range which does not include DC.
ª
Blue Noise - Blue noise is noise that is the opposite of pink noise in that it doubles the amount of energy each time you go up 1 octave.
ª
Purple noise - Purple noise's power density increases 6 dB per octave with increasing frequency (density proportional to f2) over a finite frequency range. It is also known as differentiated white noise or violet noise.
ª
Orange noise - Orange noise is quasi-stationary noise with a finite
power spectrum with a finite number of small bands of zero energy dispersed throughout a continuous spectrum.
ª
Black Noise - Noise that has a frequency spectrum of predominately zero power level over all frequencies except for a few narrow bands or spikes.
Self-Sufficient Guide to ECE by JASON AMPOLOQUIO
1-5
C. .MODULATION. Modulation is the process of varying a carrier signal, typically a sinusoidal signal, in order to use that signal to convey information. The three key parameters of a sinusoid are its amplitude, its phase and its frequency, all of which can be modified in accordance with an information signal to obtain the modulated signal.
Three General Subdivisions 1.
Analog modulation
2.
3.
Amplitude modulation (AM)
Double-sideband Full Carrier (A3E) Single-sideband Full Carrier (H3E) Single-sideband Suppressed Carrier (J3E) Single-sideband Reduced Carrier (R3E) Vestigial-sideband Modulation (C3F)
Angle Modulation
Frequency modulation (FM) Phase modulation (PM)
Digital Modulation
Amplitude Shift Keying (ASK)
Frequency Shift Keying (FSK)
Phase Shift Keying (PSK) Quadrature Amplitude Modulation (QAM) Trellis Code Modulation (TCM)
On Off Keying
Audio FSK (AFSK) Continuous Phase FSK (CP-FSK) i. Minimum-shift keying (MSK) ii. Gaussian minimum-shift keying (GMSK) iii. Very minimum-shift keying (VMSK)
Hybrid Modulation (combined analog digital techniques)
Pulse modulation
Pulse-amplitude modulation (PAM) Pulse-code modulation (PCM) i. Differential PCM (DPCM) ii. Delta Modulation (DM) iii. Adaptive DM (ADM) iv. Continuously Variable Slope Delta (CVSD) v. Sigma-Delta Modulation (∑Δ)
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Pulse Frequency Modulation (PFM) Pulse Time Modulation (PTM) i. Pulse-width modulation (PWM) ii. Pulse-position modulation (PPM) D. .WAVEFORM REPRESENTATION. 1.
Time Domain Representation
A standard oscilloscope is used to display the amplitude versus time representation of the input signal.
i.
Frequency (f) The number of times a particular phenomenon occurs in a given period of time expressed in Hertz.
ii.
Wavelength (λ) Wavelength is the distance between two points of similar cycles of a periodic wave or the distance traveled by an electromagnetic wave during the time of one cycle typically expressed in meters.
iii. Period (T) The time required for one complete cycle of a repetitive system, or simply the reciprocal of frequency. Relation between Wavelength, Frequency, and Period
λ=
c f
where: λ = wavelength in meters c = speed of light = 3 x 108 m/s f = frequency in Hertz T = period in sec
f=
c λ
T=
1 f
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1-7
ECE Board Exam: APRIL 2005
Determine the wavelength of radio waves propagated using a frequency of 30 MHz.
Solution: Wavelength : λ=
c 3 x 108 = f 30 x 106
= 10 m
2.
Frequency Domain Representation
A spectrum analyzer is used to display the amplitude versus frequency representation of the input signal.
The time and frequency domain representation of three sine waves A A
t f
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DOPPLER EFFECT
A perceived change in the frequency of a wave as the distance between the source and the observer changes.
Doppler Frequency of Sound Waves
ν ± νo fo = fs ν ∓ νs
fo = Observed frequency in Hz ν o = Velocity of observer in m/s ν s = Velocity of source in m/s fs = Source frequency in Hz
The top sign apply if the source and/or object are moving toward each other and the bottom sign apply if they move away from each other.
Sample Problem:
An ambulance travels down a highway at a speed of 75.0 mi/h with its siren emitting a sound with a frequency of 400 Hz. What frequency is heard (a) by someone standing still when the ambulance approaches? (b) by a passenger in a car traveling at 55 mi/h in the opposite direction as it approaches the ambulance? (c) by a passenger in a car traveling at 55 mi/h in the opposite direction as it moves away from the ambulance? 75 mi/h = 33.5 m/s, 55 mi/h = 24.6 m/s.
Solution:
(a) ν ≈ 345 m s , ν s = 33.5 m s, ν o = 0 (observer is not moving) fo = fs
ν + νo ⎛ 345 + 0 ⎞ = 400⎜ ⎟ = 443 Hz ν − νs ⎝ 345 − 33.5 ⎠
(b) ν ≈ 345 m s , ν s = 33.5 m s , ν o = 24.6 m s fo = fs
ν + νo ⎛ 345 + 24.6 ⎞ = 400⎜ ⎟ = 475 Hz ν − νs ⎝ 345 − 33.5 ⎠
(c) ν ≈ 345 m s , ν s = 33.5 m s , ν o = 24.6 m s fo = fs
ν − νo ⎛ 345 − 24.6 ⎞ = 400⎜ ⎟ = 339 Hz ν + νs ⎝ 345 + 33.5 ⎠
Self-Sufficient Guide to ECE by JASON AMPOLOQUIO
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Doppler Frequency of Electromagnetic Waves
fo = fs
c ± νr c ∓ νr
fo = Observed frequency in Hz c = Speed of light = 3 x 10 8 m / s νr = Velocity of source relative to observer in m/s fs = Source frequency in Hz
The top sign apply if the source and/or object are moving toward each other and the bottom sign apply if they move away from each other.
Sample Problem: A LEO communications satellite is orbiting the earth at 27,000 kph (7,500 m/s). Calculate the frequency received by a mobile station antenna due to Doppler shift 450 km below if the satellite is operating at 1.28 GHz. Also compute the Doppler shift. (Assume the satellite is moving away from the subscriber) Solution: fo = fs
c − νr c + νr
= 1.28 GHz
27,000 kph c − 7500 m s
c + 7500 m s
450 km
= 1.279968 GHz For the Doppler Shift : fD = fs − fo = 1.28 GHz − 1.279968 GHz = 31.99 kHz
E. .ENGINEERING DEFINITIONS OF BANDWIDTH. 1.
Absolute bandwidth Absolute bandwidth is the difference between the upper and lower frequency limits (f2-f1), where the spectrum is zero outside the interval f1
