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Slide # 1
EE 448
University of Southern California
Department of Electrical Engineering
Dr. Edward W. Maby
Class #1 11 January 2005
University of Southern California - EE 448 - Class #1Slide # 2
Course Personnel
Dr. Edward W. Maby (Instructor) [email protected] 740-4706 Office Hours: MW 1:00 - 2:00 PHE 626
Clint Colby [email protected]
Tyler Rather [email protected]
University of Southern California - EE 448 - Class #1Slide # 3
Grading Policy
Midterm 1 25% 17 February Midterm 2 25% 24 March Homework 15% Final Exam 35% 10 May
No Make-Up Exams Homework Conditions Borderline Grades Same “Curve” for Graduate Students
University of Southern California - EE 448 - Class #1Slide # 4
Course Objectives
Circuit Concepts for RF Systems Transmission Lines, Impedance Matching Noise and Distortion Analysis Filter Design
RF System Components Low-Noise Amplifiers, Power Amplifiers Mixers and Oscillators
Elementary Transmitter/Receiver Architectures and Their Board-Level Implementation
University of Southern California - EE 448 - Class #1Slide # 5
Why RF ?
Ever-Growing Wireless Applications Personal Communication Systems Satellite Systems Global Positioning Systems Wireless Local-Area Networks
Strong Demand for Wireless Engineers Digital is HOT Analog is COOL RF Design is an ART
University of Southern California - EE 448 - Class #1Slide # 6
Emphasis ???
Designing RF Integrated Circuits Some Engineers
Designing With RF Integrated Circuits More Engineers
Difficult to Satisfy Both Objectives
University of Southern California - EE 448 - Class #1Slide # 7
EE 448 Textbooks The Design of CMOS Radio-Frequency Integrated Circuits
Thomas H. Lee (required) Planar Microwave Engineering: A Practical Guide to Theory
Measurements and Circuits Thomas H. Lee
Radio Frequency Circuit Design W. Alan Davis and Krishna K. Agarwal
Advanced RF Engineering for Wireless Systems and Networks Arshad Hussain
Microwave and RF Design of Wireless Systems David M. Pozar
High-Frequency Techniques Joseph F. White
University of Southern California - EE 448 - Class #1Slide # 8
Some Good Advice …
Read the Syllabus Come to Class
(Come to Class Early) Do the Homework
(But Not One Hour Before a Deadline)
(And Don’t Give Up Easily) Enjoy the Course !
University of Southern California - EE 448 - Class #1Slide # 9
Basic Radio Systems
X
Modulator IF Filter Mixer
LocalOscillator
BandpassFilter
PowerAmplifier
Data In
X
LocalOscillator
BandpassFilter
Low-NoiseAmplifier
Mixer IF Filter
IFAmplifier
Demodulator
Transmitter
Receiver Data Out
University of Southern California - EE 448 - Class #1Slide # 10
Connecting the Boxes
Antenna RF Link Between Transmitter and Receiver
(Marginal Issue for EE 448) Transmission-Line Connections Between
Internal Transmitter/Receiver Components = Velocity / Frequency Circuit Dimensions Comparable to at High
Frequencies (>> 1 GHz) “Distributed” Circuit Behavior
University of Southern California - EE 448 - Class #1Slide # 11
Transmission-Line Model
Two “Wires” with Uniform Cross Section L (inductance), C (capacitance) per unit length
Transverse Electromagnetic Fields Quasi-Static Solutions L = L (, xy geometry), C = C (, xy geometry),
L C = R (resistance), G (conductance) per unit length (Consider Physical Mechanisms Later)
University of Southern California - EE 448 - Class #1Slide # 12
Telegraphers Equations
(Heaviside, 1880)
University of Southern California - EE 448 - Class #1Slide # 13
Power Implications
DissipatedPower
Change in StoredLinear Energy Density
University of Southern California - EE 448 - Class #1Slide # 14
Time-Domain Solutions
(No Loss)
Wave Equation
Forward Wave
Reverse Wave
Velocity
No Wave Dispersion (Corruption) During Propagation
University of Southern California - EE 448 - Class #1Slide # 15
Frequency Domain
v and i have Time Dependence
Propagation Constant
(Similar equation for i)
R and G may be dependent
University of Southern California - EE 448 - Class #1Slide # 16
Freq.-Domain Solutions
(V+ and V- are Fourier Amplitudes)
Similar form for i (z,t); however,
Characteristic Line Impedance
(Zo Follows Directly from Transmission-Line Model)
Forward Reverse
University of Southern California - EE 448 - Class #1Slide # 17
Low-Loss PropagationAssume (OK to 10 GHz)
• Attenuation in dB
• Attenuation in nepers
For Line Length l,
University of Southern California - EE 448 - Class #1Slide # 18
Velocities and Wavelength
Fixed Phase Angle
Phase Velocity:
Independent No Dispersion
Group Velocity:
(Applies to Modulated Signal)
Wavelength:
University of Southern California - EE 448 - Class #1Slide # 19
Historical Remarks
(Transatlantic Cable)
First Telegrapher’s Equations: (No L or G)
Prof. William Thomson (Later Lord Kelvin) 1854
DiffusionEquation
(Applies to Most Ordinary IC Interconnects)
University of Southern California - EE 448 - Class #1Slide # 20
Diffusion Solutions
Unit-Step Input:
For line length l, imax at
Pulse Input:
University of Southern California - EE 448 - Class #1Slide # 21
Diffusion “Velocity”
Sinusoidal Input:
“Velocity”
Dispersion, High-Frequency Attenuation
University of Southern California - EE 448 - Class #1Slide # 22
Did Engineers Care?
Dr. Edward Orange Wildman Whitehouse M.D.Chief Electrician, Atlantic Telegraph Company, 1856
“In all honesty, I am bound to answer, that I believe natureknows no such application of that law; and I can only regardit as a fiction of the schools, a forced and violent adaptationof a principle in Physics, good and true under other circum-stances, but misapplied here.”
On Thomson’s Results …
First Transatlantic Cable (1858)
Whitehouse: Long Cable Requires Large-Voltage Input 2000-V “Stroke of Lightning” per Pulse (Obviously)
Nahin, p. 34
University of Southern California - EE 448 - Class #1Slide # 23
What Happened Next?
Queen Victoria and James Buchanan Exchange Messages Great Celebration, Public Pleased Cable Insulation Fails, Cable Dead, Public Angry Boston Headline: Was the Atlantic Cable a Humbug? Investor: Was Cyrus Field an Inside Trader? Further Experiments: High Voltage Not Necessary
Whitehouse Fired Second Transatlantic Cable Successful (1866)
University of Southern California - EE 448 - Class #1Slide # 24
Minimal Dispersion ?
Telegraph Lines Make Poor Telephone Lines
(Bell Fails to Propagate Voice Over Atlantic Cable - 1877)
?
Heaviside (1887)
Increase L by Adding Series Loading Coils at /4 Intervals
Improve Audio Bandwidth, But Suppress High Frequencies
H88 Standard (88 mH at 6000-foot Intervals) Bad for DSL
University of Southern California - EE 448 - Class #1Slide # 25
Dispersion - Skin Effect
Skin Depth
Real Part: Amplitude DistortionImaginary Part: Phase Distortion
Rise Time
University of Southern California - EE 448 - Class #1Slide # 26
Dispersion - Dielectric Loss
Dielectric Constant Has Real and Imaginary Parts
(Loss Tangent)
Loss
General Relation for Capacitance:
Dielectric Loss Overtakes Skin-Depth Loss (f >> 1 GHz)
University of Southern California - EE 448 - Class #1Slide # 27
Digital Digression
Dispersion Promotes Inter-Symbol Interference
Equalization at Receiver Correct for Group Delay Correct for Amplitude Distortion Difficult for Very-High Data Rates
Pre-Emphasis (Pre-Distortion) at Transmitter Increase Pulse Amplitude After Transition MAX3292 (for RS-485) See Widmer et al. (IBM)
IEEE JSSC 31, 2004 (1996)
University of Southern California - EE 448 - Class #1Slide # 28
Why 50 Ohms?Consider Coaxial Cable With Inner and Outer Diameters a and b
Maximum Deliverable Power:
Zo = 30
Minimum Attenuation:
Zo = 77
Compromise: Zo = 50
(75 - Cable TV)
(Lee, pp. 229-231)
University of Southern California - EE 448 - Class #1Slide # 29
Microstrip Linesw
hSubstrate
Important Substrate Properties Relative Dielectric Constant Loss Tangent Thermal Conductivity Dielectric Strength
Numerous Design Equations for Zo and Effective See Davis and Agarwal, pp. 71-74; Chang, pp. 43-49 Calculator: http://mcalc.sourceforge.net/#calc
University of Southern California - EE 448 - Class #1Slide # 30
Design Formulas
Define
Then
Assumes “Narrow” Lines
University of Southern California - EE 448 - Class #1Slide # 31
References
Richard B. Adler, Lan Jen Chu, and Robert M. Fano, Electromagnetic Energy Transmission and Radiation (1960)
Paul J. Nahin, Oliver Heaviside: The Life, Work, and Times of an Electrical Genius of the Victorian Age (1988)
Henry M. Field, History of the Atlantic Telegraph (1866) Kai Chang, RF and Microwave Wireless Systems (2000) Richard E. Matick, Transmission Lines for Digital and
Communication Networks (1969)
(Other than course texts)