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Electric Circuits (Fall 2015) Pingqiang Zhou
Electric Circuits
Lecture 1 - Introduction
Instructor: Dr. Pingqiang Zhou
Fall 2015
Lecture 1 1
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 2
Course Overview
• First core course of SIST (EECS)
Introduces “hardware” side of EECS
• Prerequisite for all subsequent EE courses
• Involves (per week) at least
4 hours of lecture
2 hours of discussion
3 hours of lab
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 3
Instructor
• Dr. Pingqiang Zhou
• Lecture
Tuesday, 10:15AM – 11:55AM
Thursday, 13:00PM – 14:40PM
Venue: Teaching building 306
• Office hours
TBD
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 4
GSIs - Discussion
• Class 1, Mon. 8:15AM - 9:55AM
GSI: 曹阳阳<[email protected]>
• Class 2, Wed. 8:15AM - 9:55AM
GSI: 商德佳 <shangdj>
• Class 3, Fri. 8:15AM - 9:55AM
GSI: 赵晖<zhaohui>
• Class 4, Fri. 10:15AM - 11:55AM
GSI: 张久鑫<zhangjx1>
GSI - Graduate Student Instructors
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 5
GSIs - Lab
• Class 1, Mon. 1PM - 3:45PM
GSI: 刘圣波 <liushb>
• Class 2, Mon. 5:45PM - 8:20PM
GSI: 黄景林 <huangjl>
• Class 3, Fri. 1PM - 3:45PM
GSI: 陈晨<chenchen2>
• Class 4, Fri. 5:45PM - 8:20PM
GSI: 孙天宇<sunty>
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 6
Workload
• 12 homeworks
• 12 labs
NO late HW or Lab reports accepted!
• 2 midterms + 1 final exam
Midterm 1: week 6 (tentative)
Midterm 2: week 12 (tentative)
Notify the instructor immediately if you miss an exam due to an
unforeseeable event, and submit a note from your physician in
case of illness.
NO make-up exams!
• Quizzes Quizzes are held in-class and will not be announced. There won’t
be any makeup quizzes.
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 7
Grading Policy
• Homeworks: 12 x 2% = 24%
• Labs: 12 x 2% = 24%
• Midterms: 2 x 16% = 32%
• Final: 20%
• Quiz scores may be used for rounding to the nearest letter
grade.
• A typical GPA for courses in the lower division is 2.7. This
GPA would result, for example, from 17% A's, 50% B's,
20% C's, 10% D's, and 3% F's.
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 8
Classroom Rules
• Please come to class on time.
• Turn off cell phones, radio, CD, etc.
• No food and no pets.
• Do not move in and out of, or around the classroom.
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 9
Course Website
• http://sist.shanghaitech.edu.cn/faculty/zhoupq/Teaching/Fall15/Electric_Circuits.html
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 10
Outline
• Brief introduction to Electrical Engineering (EE)
• EE courses in SIST
• Topics covered in this course
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 11
What is Electrical Engineering (EE)?
• “EE is the profession concerned with systems that
produce, transmit, and measure electric signals. Electrical
engineering combines the physicist’s models of natural
phenomena with the mathematician’s tools for
manipulating those models to produce systems that meet
practical needs.” James W. Nilsson and Susan Riedel, Electric Circuits, 10th edition, Prentice
Hall, 2014.
• “Electrical engineers design systems that have two main
objectives:
1.To gather, store, process, transport, and present information.
2.To distribute, store, and convert energy between various forms.”
Allan R. Hambley, Electrical Engineering – Principles and Applications, 5th
edition, Prentice Hall, 2011.
Electric Circuits (Fall 2015) Pingqiang Zhou
Major Areas of
Electrical Engineering
(EE)
12Lecture 1
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 13
Communication Systems
• Transport information in electrical form.
[Source: Google Image]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 14
Signal Processing
• Concerned with information-bearing electrical signals
Objective: extract useful information from electrical signals
derived from sensors.
[Source: Google Image]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 15
Computer Systems
• Process and store information using electrical signals.
[Source: Google Image]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 16
Control Systems
• Use electric signals to regulate processes.
[Source: Google Image]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 17
Electromagnetics
• Study and application of electric and magnetic fields.
[Source: Google Image]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 18
Electronics
• Study and application of materials, devices and circuits
used in amplifying and switching electrical signals.
[Source: Google Image]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 19
Photonics
• An exciting new field that manipulates photons, instead of
manipulating electrons in conventional computing, signal
processing, sensing and communication.
[Source: Google Image]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 20
Power Systems
• Convert energy to and from electrical form and transmit
energy over long distances.
[Source: Google Image]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 21
The “Smart” Grid
[Source: Google Image]
Electric Circuits (Fall 2015) Pingqiang Zhou
Electrical Engineering
Lecture 1 22
EE = Electrical Engineering?
Electronics
Photonics
Electromagnetics
Communications
ComputerSystems
PowerSystems
SignalProcessing
ControlSystems
Electric Circuits (Fall 2015) Pingqiang Zhou
Some History of
Electrical Engineering
23Lecture 1
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 24
Back to the Early 17th Century
• William Gilbert (1544 - 1603), English
First (?) electrical engineer - Designed versorium, a device to
detect the presence of static electric charge.
Established the term electricity.
[Source: Wikipedia]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 25
• Alessandro Volta (1745 – 1827), Italian
In 1775, devised electrophorus, a
device that can produce static electric
charge.
In 1796, developed voltaic pile, the first
electrical battery.
[Source: Wikipedia]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 26
• Andre-Marie Ampere (1775 - 1836), French
The father of electrodynamics (classical electromagnetism)
In the1820s, defined the electric current and developed a
way to measure it.
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 27
• Georg Simon Ohm (1789 - 1854), German
In 1827, quantified the relationship between the electric
current and potential difference in a conductor, i.e., the
“Ohm’s law”.
[Source: Wikipedia]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 28
• Michael Faraday (1791 - 1867), English
In 1831, discovered electromagnetic induction.
One of Faraday's 1831 experiments demonstrating
induction. The liquid battery (right) sends an electric
current through the small coil (A). When it is moved
in or out of the large coil (B), its magnetic field
induces a momentary voltage in the coil, which is
detected by the galvanometer (G).
[Source: Wikipedia]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 29
Alternating Current (AC)
• Hippolyte Pixii (French, 1808 - 1835)
In 1832, built an early form of AC electrical generator, based
on the principle of magnetic induction discovered by Faraday.
[Source: Wikipedia]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 30
• James Clerk Maxwell (1831 - 1879), Scottish
Formulated the classical theory of electromagnetic radiation
(Maxwell’s equations)
The electromagnetic waves that compose
electromagnetic radiation can be imagined as a
self-propagating transverse oscillating wave of
electric and magnetic fields.
This diagram shows a plane linearly polarized
EMR wave propagating from left to right. The
electric field is in a vertical plane and the
magnetic field in a horizontal plane. The electric
and magnetic fields in EMR waves are always in
phase and at 90 degrees to each other.
[Source: Wikipedia]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 31
In 1830s, Electricity for Practical Use
• Cooke and Wheatstone’s
first commercial telegraph in
the world (1838), installed on
the Great Western Railway
(London, 21km).A Morse key
Major telegraph lines across the Earth in 1891
• Morse and Vail’s system
Patented in the US in 1837.
West coast connected by
1861.
[Source: Wikipedia]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 32
Bell (Scottish, 1847 - 1922)
• Alexander Graham Bell was the
first to be awarded a patent for the
electric telephone by the United
States Patent and Trademark
Office (USPTO) in March 1876.
• 10 March 1876 — The first
successful telephone transmission
of clear speech using a liquid
transmitter when Bell spoke into
his device, “Mr. Watson, come
here, I want to see you.” and
Watson heard each word distinctly.
[Source: Wikipedia]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 33
Tesla (Croatia, 1856 - 1885)
• Best known for his contributions to the design of the modern
alternating current (AC) electricity supply system.
• In 1891 Nikola Tesla demonstrate wireless transmission of
signals and he suggested wireless telegraphy as an
application.
AC electric generator Artificial lighting Wireless transmission
[Source: Wikipedia]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 34
Wireless/Radio
• Started as wireless telegraphy.
The history of the invention of
the radio is very disputed.
• Guglielmo Marconi (Italian,
1874 - 1937) widely recognized
as an early inventor although
he played a more important
role in commercializing the
radio.
In 1895, he sent signals 1.5km.
Transatlantic in 1902.
Wireless /Radio
! Started as wireless telegraphy. The history
of the invention of the radio is very
disputed.
! Marconi widely recognized as an early
inventor although he played a more
important role in commercializing the
radio. In 1895 he sent signals 1.5 km.
Transatlantic in 1902.
Copyright © Prof. Ali M Niknejad
Wireless /Radio
! Started as wireless telegraphy. The history
of the invention of the radio is very
disputed.
! Marconi widely recognized as an early
inventor although he played a more
important role in commercializing the
radio. In 1895 he sent signals 1.5 km.
Transatlantic in 1902.
Copyright © Prof. Ali M Niknejad
[Source: Wikipedia]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 35
Titanic Boost in Radio
• In 1912, the RMS Titanic sank
in the northern Atlantic Ocean.
• Wireless radio transmissions
(telegraph) were used to report
the ship’s location.
• Britain's postmaster-general
summed up, referring to the
Titanic disaster, “Those who
have been saved, have been
saved through one man, Mr.
Marconi...and his marvelous
invention.”
Titanic Boost in Radio
! In 1912, the RMS Titanic sank
in the northern Atlantic Ocean.
! Wireless radio transmissions
(telegraph) were used to report
the ship’s location.
! Britain's postmaster-general
summed up, referring to the
Titanic disaster, “Those who
have been saved, have been
saved through one man, Mr.
Marconi...and his marvellous
invention.”
Copyright © Prof. Ali M Niknejad [Source: Wikipedia]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 36
First Audio Transmissions
• Reginald Fessenden: Invented
amplitude-modulated (AM) radio, so
that more than one station can send
signals (as opposed to spark-gap radio,
where one transmitter covers the entire
bandwidth of the spectrum).
• On Christmas Eve 1906, Reginald
Fessenden made the first radio audio
broadcast, from Brant Rock, MA.
• Ships at sea heard a broadcast that
included Fessenden playing O Holy
Night on the violin and reading a
passage from the Bible.
First Audio Transmissions
! Reginald Fessenden: Invented
amplitude-modulated (AM) radio,
so that more than one station can
send signals (as opposed to spark-
gap radio, where one transmitter
covers the entire bandwidth of the
spectrum).
! On Christmas Eve 1906, Reginald
Fessenden made the first radio
audio broadcast, from Brant Rock,
MA. Ships at sea heard a
broadcast that included Fessenden
playing O Holy Night on the
violin and reading a passage from
the Bible. Copyright © Prof. Ali M Niknejad
[Source: Wikipedia]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 37
AM/FM Wireless Radio
• The dominant telegraph company of the time was
Western Union. They had a monopoly on telegraphy and
they dismissed telephony and radio.
• Telegraph gave way to audio transmission, mainly phone
lines and broadcast radio.
• Frequency modulation (FM) was invented by Armstrong in
1935. FM has greater noise immunity than AM but
requires more bandwidth.
AM/FM Wireless Radio
! The dominant telegraph company of the time was Western
Union. They had a monopoly on telegraphy and they
dismissed telephony and radio.
! Telegraph gave way to audio transmission, mainly phone
lines and broadcast radio.
! Frequency modulation (FM) was invented by Armstrong in
1935. FM has greater noise immunity than AM but
requires more bandwidth.
Copyright © Prof. Ali M Niknejad
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 38
Digital Communications
• By sampling a signal and quantizing it (turning it into finite
precision numbers), we can easily store it using digital
technology and we can also transmit it digitally.
• Audio signals, for example, need to be sampled at about
20,000 times per second and with a resolution of around
18 bits to completely retain the fidelity of the signal (for the
human ear)
• Today information is still transmitted with AM and FM, but
the amplitude and phase of the signal are mapped into a
finite alphabet. These digital signals are more noise
immune and can be coded (guarded) to prevent, correct,
and detect errors in transmission.
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 39
The TransistorThe Transistor
! Invented at Bell Laboratories on December 16, 1947 by
William Shockley (seated at Brattain's laboratory bench),
John Bardeen (left) and Walter Brattain (right)
! Inventors awarded Nobel Prize
! Probably the most important even in EE history
Copyright © Prof. Ali M Niknejad
• Invented at Bell Laboratories on December 16, 1947 by William Shockley
(seated at Brattain's laboratory bench), John Bardeen (left) and Walter
Brattain (right).
▪ Inventors awarded Nobel Prize.
• Probably the most important event in Electronic Engineering history.
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 40
Early Transistors
• Bell labs was the research lab of a
telephone company. As such the
importance of the transistor was not
recognized by many of the business folks
at AT&T.
• Device was flaky and low power
compared to vacuum tubes, the
workhorse device of the time (for signal
amplification)
• In 1952 first transistorized radios appear.
Compared to vacuum tube, transistors
were compact.
• Transistor radio was a revolutionary
battery operated device.
Early Transistors
! Bell labs was the research lab of a
telephone company. As such the
importance of the transistor was not
recognized by many of the business
folks at AT&T.
! Device was flaky and low power
compared to vacuum tubes, the
workhorse device of the time (for signal
amplification)
! In 1952 first transistorized radios appear.
Compared to vacuum tube, transistors
were compact.
! Transistor radio was a revolutionary
battery operated device.
Copyright © Prof. Ali M Niknejad
http://en.wikipedia.org/wiki/File:Sanyo_Transistor.jpg!
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 41
The Integrated Circuit (IC)The Integrated Circuit
! First IC is invented by Jack Kilby of Texas Instruments and
Robert Noyce of Fairchild Semiconductor (later founded Intel)
! In his patent application of February 6, 1959, Kilby described
his new device as “a body of semiconductor material ... wherein
all the components of the electronic circuit are completely
integrated.” (2000 Nobel Prize in Physics) Copyright © Prof. Ali M Niknejad
http://en.wikipedia.org/wiki/File:Kilby_solid_circuit.jpg!
• First IC is invented by Jack Kilby of Texas Instruments and Robert Noyce of
Fairchild Semiconductor (later founded Intel).
• In his patent application of February 6, 1959, Kilby described his new device
as “a body of semiconductor material ... wherein all the components of the
electronic circuit are completely integrated.” (2000 Nobel Prize in Physics)
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 42
Why IC’s were Revolutionary?
• When building a complex
circuit, most of the failures
occur in the wiring and
connections of wires.
• Printed circuit boards help
improve reliability but they are
physically large and discrete
components are fairly
expensive.
• ICs: Low cost mass production,
monolithic, includes transistors
and interconnect.
Why IC’s were revolutionary:
! When building a complex
circuit, most of the
failures occur in the
wiring and connections
" spaghetti of wires
! Printed circuit boards
help improve reliability
but they are physically
large and discrete
components are fairly
expensive
! ICs: Low cost mass
production, monolithic,
includes transistors and
interconnect. Copyright © Prof. Ali M Niknejad
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 43
Outline
• Brief introduction to Electrical Engineering (EE)
• EE courses in SIST
• Topics covered in this course
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 44
EE Trichotomy
• Devices
You can “touch and feel” devices
Semiconductors are materials of choice
Information is ultimately represented by electrons (and
‘holes’) and/or photons
• Circuits
Interconnection of devices that performs a useful function
Digital circuits, analog circuits, “RF” and microwave
• Systems
The theory behind EE systems. A model for the system that
includes noise, non-linearity, feedback and dynamics.
Most often digital signal processing algorithms used.
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 45
Devices
• Devices: Physical stuff you can “touch and feel”
Manufacturing driven largely by integrated circuit (IC)
fabrication.
The building block of ICs: Transistors.
• Devices include electronic devices and optical devices
Electron (and “hole”) transport through metals and semiconductors
Semiconductors can be engineered to have specific properties.
(conductivity). The junction between two semiconducting materials
is where the magic happens.
Photons (light) used to carry information through waveguides (fiber
optics) or through electromagnetic radiation (radios, wireless).
Semiconductor junctions can generate photos or detect photons
(optical receivers, solar cells).
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 46
How does a Transistor Work?How does a transistor work?
! Metal-Oxide-Semiconductor sandwich. Usual structure is
actually polysilicon, silicon dioxide, silicon. (Note that the
original transistor fabricated was not an MOS device.)
! A “channel” for current flow can be setup between the drain/
source.
! The channel conduction (between drain and source) is controlled
by the gate voltage. Copyright © Prof. Ali M Niknejad
p-type substrate
n+ n+
source drain
diffusion regions
gate
body
p+
• Metal-Oxide-Semiconductor sandwich. Usual structure is actually polysilicon,
silicon dioxide, silicon. (Note that the original transistor fabricated was not an
MOS device.)
• A “channel” for current flow can be setup between the drain/ source.
• The channel conduction (between drain and source) is controlled by the gate
voltage.
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 47
MEMS (Micro Electro-Mechanic Systems)
• Use the same technology for building chips but now build
mechanical structures!
Often older process nodes can be used which brings the cost down.
• Common MEMS devices include accelerometers for
automobile airbags and for devices such as the cell phone.
iPhone popularized the tilt function using an accelerometer.
• Active research on building high Q resonators with MEMS
technology for radio applications.
[Source: Wikipedia]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 48
Circuits
• When devices are interconnected to perform some useful
function, we say that thing is a circuit.
• Examples:
A light bulb/switch, spark generator in internal combustion
engine, a radio, a cell phone, a computer
• A typical “circuit” may contain millions of devices. How do
we deal with this level of complexity?
Hierarchy: Divide and conquer
A large circuit is broken up into my sub-blocks
Sub-blocks are broken up into sub-blocks ...
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 49
Analog Circuits
• Analog circuit represents the signal as an electrical
current/ voltage.
• Typical analog circuits:
Amplify signals (weak signal picked up by microphone)
Filter signals (remove unwanted components, interference,
noise)
Perform mathematical operations on waveform
–Multiplication, differentiation, integration.
• Circuits very susceptible to noise and distortion.
• Analog circuits are “hand crafted” by analog “designers”
• Attempts to automate analog design (Computer Aided
Design or CAD) have largely failed.
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 50
An ECG Front-EndAn ECG Front-End
Copyright © Prof. Ali M Niknejad [Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 51
Digital Circuits
• Represent quantities by discrete voltages, “1” and “0” (e.g.
1V and 0V) – “bits”
• Digital circuits perform “logic” operations on the signals
(AND, OR, XOR) – “combinatorial logic”.
• Mathematical operations can be performed using logic
operations (XOR is a 1-bit adder).
• Digital memory created using capacitors (dynamic
memory) or through latches/flip-flops (regenerative circuits)
• Digital circuits are robust against noise (signal levels are
regenerated to “0” and “1” after digital functions).
• Digital circuits often “clocked” to simplify design.
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 52
Ripple Carry Adder
• The above circuit is a full adder. The input bits are A, B,
and Cin (carry in). The output is the sum S and Cout (carry
out).
• By chaining together many of these elements, we can
produce an adder of any desired precision.
Ripple Carry Adder
! The above circuit is a full adder. The input bits are A, B,
and Cin (carry in). The output is the sum S and Cout
(carry out).
! By chaining together many of these elements, we can
produce an adder of any desired precision.
Copyright © Prof. Ali M Niknejad
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 53
Systems
• There is a strong theoretical foundation in EE that helps
engineers understand and improve electronic systems
What is the correct stochastic representation of signals?
How fast do you need to sample a signal in order to preserve its
content so you can process it digitally (Nyquist Sampling Theorem)?
How much information can be transmitted (without error) in a given
bandwidth (say your telephone cables) when we assume the
channel is corrupted by additive white Gaussian noise? ->
Shannon’s Famous Capacity Theorem
–Modems: 300-9600 baud, 28.8k, 56k
– Today: 1-10 Mbps+
How do you design a wireless system to contend with multi-path
propagation? What are the performance limits?
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 54
Digital Signal Processing
• A continuous time band-limited signal (audio, video, radio
signal) can be sampled at a rate of twice the highest
frequency of interest without any information loss.
• The discrete time representation of the signal can be
quantized (information loss) and stored in a computer.
These signals can be manipulated using Digital Signal
Processors (DSP) or custom IC’s to perform complex
mathematical operations.
Examples include echo cancellation, channel equalization,
compression, filtering.
• DSP allows extremely complex communication systems to
be realized using low cost hardware.
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 55
Image Compression
• A digital image contain redundancy. Simple
lossless compression schemes include run-
length coding. More sophisticated
compression schemes try to use only a few
bits for signals that occur often and many
bits for signals that occur rarely. This
process is automatically done using Hoffman
coding.
• Lossy compression throws away information,
but in a way so as to minimize the impact on
the quality of the signal.
• Images contain a lot of high frquency spatial
data that can be discarded (JPEG
compression).
Image Compression ! A digital image contain redundancy.
Simple lossless compression schemes
include run-length coding. More
sophisticated compression schemes try to
use only a few bits for signals that occur
often and many bits for signals that occur
rarely. This process is automatically
done using Hoffman coding.
! Lossy compression throws away
information, but in a way so as to
minimize the impact on the quality of the
signal.
! Images contain a lot of high frquency
spatial data that can be discarded (JPEG
compression).
Copyright © Prof. Ali M Niknejad
Image Compression ! A digital image contain redundancy.
Simple lossless compression schemes
include run-length coding. More
sophisticated compression schemes try to
use only a few bits for signals that occur
often and many bits for signals that occur
rarely. This process is automatically
done using Hoffman coding.
! Lossy compression throws away
information, but in a way so as to
minimize the impact on the quality of the
signal.
! Images contain a lot of high frquency
spatial data that can be discarded (JPEG
compression).
Copyright © Prof. Ali M Niknejad
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 56
MP3 Audio Files
• MP3 files take advantage of the psychoacoustic
properties of the human ear/mind to compress audio files
by an order of magnitude (An entire uncompressed CD
contains 700MB of data, or about 80 minutes of music.
You can get about 800 minutes after compression).
The signal is chopped up in the frequency domain into bins.
Each bin is coded with the number of bits commensurate
with the required resolution based on our hearing ability.
Examples: A strong tone can “jam” nearby tones. You can’t
hear a weak tone next to a strong tone.
• Early computers could not decompress MP3 in real time!
[Source: Berkeley]
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 57
EE Courses offered in SIST
EE111 Electric Circuits
EE131 Semiconductor devices EE133/533 Optoelectronic devicesEE112 Electromagnetics
EE122 Digital CircuitsEE121 Analog Circuits EE113 Microwave Circuits
EE131/531 Analog IC EE132/532 Digital IC
EE143 Communication systems EE144 Communication networks
EE141 Signals and systems EE141/541 Digital signal processing
EE162 Control theory
EE161 Electric power systems
EE133 Power electronics
CS130/131/530 Computer architecture
EE534 VLSI design automation
EE543 Digital communications EE544 Wireless communications
EE545 Channel coding theory
EE546 Signal detection and parameter estimation
EE550 Linear systems EE551 Nonlinear systemsEE552 Stochastic control
EE540 Information theory
EE520 RF electronics
Electric Circuits (Fall 2015) Pingqiang Zhou
In a field as diverse as electrical
engineering, does all its branches
have anything in common?
58Lecture 1
Electric Circuit!- an actual electrical system, as
well as the model that represents it.
Electric Circuits (Fall 2015) Pingqiang Zhou
59Lecture 1
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 60
Electrical Engineering Design
Need
Design specification
ConceptCircuit
Model
(ideal
compon
ents)Physical
Prototype
(actual
electrical
system)
Physical
insight
Circuit
analysis
Circuit which
meets design
specifications
Refinement based
on analysis
Laboratory
measurements
Refinement based
on measurements
[Nilsson: Electric Circuits]
• An ideal circuit component:
mathematical model of an
actual electrical component.
• Circuit analysis plays a very
important role in the design
process.
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 61
Outline
• Brief introduction to Electrical Engineering (EE)
• EE courses in SIST
• Topics covered in this course
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 62
What will You Learn from “Electric Circuits”?
• An electric circuit is an interconnection of electrical
elements.
• Theory: You will learn various analysis methods in
lectures to analyze the behavior of such electric circuits.
How does the circuit respond to a given input?
How do the elements and devices in the circuit interact?
• Practice: You will also learn how to build and test basic
electric circuits through labs and projects!
Electric Circuits (Fall 2015) Pingqiang Zhou
Textbook
• Charles K. Alexander and Matthew N. O. Sadiku,
Fundamentals of Electric Circuits, 5th edition, McGraw Hill,
2012.
6Lecture 1
Electric Circuits (Fall 2015) Pingqiang Zhou
References
• James W. Nilsson and Susan Riedel, Electric Circuits, 10th edition, Prentice Hall,
2014.
• Allan R. Hambley, Electrical Engineering – Principles and Applications, 5th
edition, Prentice Hall, 2011.
• Anant Agarwal and Jeffrey Lang, Foundations of Analog and Digital Electronic
Circuits, Morgan Kaufmann, 2005.
6Lecture 1
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 65
Topics Covered in This Course (Tentative)
• Intro to circuits: currents, voltages; power/energy; circuit elements
• DC circuits
Basic circuit laws (Ohm, Kirchhoff, Wye-Delta etc.)
Circuit analysis: nodal analysis and mesh analysis
Circuit theorems: Thevenin, Norton, Superposition
Operational amplifiers: ideal, inverting/non-inverting, summing and
difference)
Inductance, capacitance and mutual inductance
First-order and second-order circuits
• AC circuits
Sinusoidal steady-state analysis and power calculations
Three-phase circuits; magnetically coupled circuits
Frequency response: transfer function; resonance; filters
• Laplace transform, Fourier transform
• Two-port networks
Electric Circuits (Fall 2015) Pingqiang Zhou
Lecture 1 66
Next Lecture and Reminders
• Next lecture
Thursday
• Reading assignment
Ch. 1 (of text)
• Reminders
HW1 will be out by this weekend
–due Oct. 8
Lab1 is on going
Lab2 will be posted by this weekend