Download ECE357 introduction slides

Welcome!
ECE357H1S: Electromagnetic
Fields
Lecture Section L01
Prof. Sean Victor Hum
ECE357 / Prof. S. V. Hum
Welcome
•  Course website via Blackboard
http://portal.utoronto.ca
http://www.waves.utoronto.ca/prof/svhum/
ece357.html
•  Important information distributed through
Blackboard
–  Notes, problem sets, announcements, …
•  Please login and familiarize yourself with the site
ECE357 / Prof. S. V. Hum
Contact Information
Prof. Sean Victor Hum
BA5122
[email protected]
Office hours:
–  Tuesdays 4-5pm
–  Anytime by appointment
ECE357 / Prof. S. V. Hum
Textbook / References
•  Required
–  D. Cheng, Field and Wave Electromagnetics, 2nd ed.,
Addison-Wesley, 1989
•  Recommended
1.  K. R. Demarest, Engineering Electromagnetics,
Prentice-Hall, 1997
2.  Simon Ramo, John R. Whinnery, and Theodore Van
Duzer, Fields and Waves in Communication
Electronics, 3rd Ed.
3.  E.M Purcell, Electricity and Magnetism, Vol. II, 2nd
Ed., (Berkeley Physics Series)
ECE357 / Prof. S. V. Hum
Course Grading
Term Test 1
15%
Term Test 2
15%
Quizzes
(approx. bi-weekly, 5 total)
10%
Laboratory Work
(bi-weekly, 3 experiments)
15%
Final exam
35%
ECE357 / Prof. S. V. Hum
Lectures
•  Material follows course notes but expect
variations in depth (i.e. keep good notes!)
•  I will run frequent surveys after lectures to
determine which concepts are causing the
most difficulty (‘muddiest concepts’)
–  Please participate!
–  This will help me tailor lecture and online
materials to help you the most
ECE357 / Prof. S. V. Hum
Tutorials / Assignments
•  Weekly tutorials (1 hour tutorial format)
•  Tutorials will cover previous and present
week of material
•  Weekly problem sets, not marked
–  Issued Mondays
–  Solutions covered in tutorials, online
•  Quizzes held at conclusion of tutorial (last
10 minutes)
–  5 total, bi-weekly, see schedule
ECE357 / Prof. S. V. Hum
Laboratories
•  3 laboratories, bi-weekly
–  Starting week of February 1 – see schedule
•  Experiment 1: Design of a double-stub matching
network
•  Experiment 2: Waves on transmission lines
•  Experiment 3: Standing waves and waveguides
•  Laboratory reports
–  Completed individually and independently
–  Due two weeks later at 16:00 in collection boxes (4th
floor Bahen building)
ECE357 / Prof. S. V. Hum
Term Tests (2)
•  Scheduled outside lecture time, TBD
•  Cover to the beginning of the course, but
with emphasis on un-tested material.
•  One double-sided 8.5x11” aid sheet
allowed (same for final exam)
ECE357 / Prof. S. V. Hum
Why Study Fields and Waves?
•  All of our electronics, radio/microwave,
photonic/optical, and X-ray devices rely on
properties of electric and magnetic fields
•  EM theory applies to all electromagnetic
fields, regardless of frequency
ECE357 / Prof. S. V. Hum
The Electromagnetic Spectrum
ECE357 / Prof. S. V. Hum
LG
12
USS Shiloh - Radar console in the Combat Information Center
13
Cosmic microwave
background radiation
ESO/José Francisco Salgado (josefrancisco.org)
14
Real-time MRI of a human heart
Tomáš Vendiš, Wikimedia / Wikipedia
15
MDA / ESA
Photonics
MDA
/ ESA Sweden
Circuit Theory vs. EM Field Theory
•  When the size of a
structure is much smaller
than a wavelength, there
is negligible variation in
the electric/magnetic
fields (voltages/currents)
across the structure
–  Can apply circuit theory
(KCL, KVL, …)
ECE357 / Prof. S. V. Hum
Circuit Theory vs. EM Field Theory
•  As the structure gets large / wavelength gets
small, such that this is no longer true, circuit
theory is no longer applicable
–  Need EM theory to analyze the system
ECE357 / Prof. S. V. Hum
EM Field Quantities
ECE357 / Prof. S. V. Hum
Maxwell’s Equations
•  EM theory is completely characterized by 4
major vector equations:
Constitutive relations (simple
media):
•  Before delving to deeply into these, we will start
with transmission lines which are closer to
circuits
ECE357 / Prof. S. V. Hum
What you will learn in ECE320
• 
• 
• 
• 
Transmission line theory
Fundamental electromagnetics theory
Unguided waves in space: plane waves
Guided waves and waveguides
ECE357 / Prof. S. V. Hum
Transmission Line Theory
•  Transmission lines are
used in countless ways in
modern society
–  Communications
–  Electronic circuits /
computers
–  Power distribution
–  Photonics
–  …
•  TL theory becoming
increasingly relevant in
modern circuit design as
clock frequencies
continue to climb
–  “Signal integrity
engineering”
ECE357 / Prof. S. V. Hum
Transmission Line Theory
•  You will learn:
–  Voltage and current
waves on a
transmission line
–  Transient and
harmonic behaviour of
transmission lines
–  Use of the Smith Chart
–  How to design
transmission line
matching circuits
ECE357 / Prof. S. V. Hum
Fundamental EM Theory
•  You will learn:
–  Maxwell’s equations
–  Boundary conditions
–  Helmholtz equation
•  Theoretical building
blocks for studying
guided/unguided EM
waves
ECE357 / Prof. S. V. Hum
Unguided Waves
•  Examples:
–  Radio waves broadcast
from an antenna
–  Light radiation from a laser
–  X-rays
•  Plane waves are simple
approximations of waves
in real life that can be
used to study the
propagation of
electromagnetic fields in
free space
ECE357 / Prof. S. V. Hum
Unguided Waves
•  You will learn:
–  Plane waves and propagation characteristics
–  Transmission and reflection at a variety of
media interfaces
–  Analogies with transmission lines
ECE357 / Prof. S. V. Hum
Guided Waves
•  More advanced analysis
of various transmission
lines and modes for
guiding EM waves
•  Specific examples:
– 
– 
– 
– 
Rectangular waveguide
Parallel plate waveguide
Planar transmission line
Dielectric-based
transmission lines (e.g.
fibre optics)
ECE357 / Prof. S. V. Hum
Transmission Lines
ECE357 / Prof. S. V. Hum
What is a Transmission Line?
ECE357 / Prof. S. V. Hum
Examples of Transmission Lines
31
ECE357 / Prof. S. V. Hum
Transmission Line Example
Consider a modern PC motherboard:
•  The bus line is a two-conductor transmission line
•  Let us connect a source (e.g. clock oscillator) to the line and terminate
the line in a resistive load
•  We will now vary the frequency of the source to change the wavelength λ
ECE357 / Prof. S. V. Hum
Transmission Line Voltage
Observations
z
Let’s observe the voltage at many points along the line (relative to the
ground plane) and observe the behaviour as a function of time
ECE357 / Prof. S. V. Hum
Question
•  What kind of equivalent circuit allows the
effect of the source to be delayed the way
we have seen in the demonstration?
ECE357 / Prof. S. V. Hum