ECE 391 - Transmission Lines (Continually under revision!)
CRN 53511 Spring 2022

Lecture:  M,W,F 0900-0950; LPSC 125
  Roger Traylor  (remove NOSPAM)
  Office Hours: Variable

  Omer Faruk Firat  (remove NOSPAM)
  Office hours: Th, 11am Kelley 4126

  Ismail Uluer  (remove NOSPAM)
  Office hours: Tue, 11am Kelley 4126

About this Class

ECE391 is focused on the design and use of electrical structures that deliver electrical waveforms to electrically distant loads. There are two different realms we will look at, finding in the end that they are closely related and they represent different ways of looking at waveforms.

The first part of the course will be focused on digital waveforms. These typically are "0" or "1" signals being sent from one digital driver, to one or more loads. Waveforms are transient, transitioning from one level to another in an abrupt, step function way.

The second portion of the course is focused on the analog realm. Analog signals are continuous in nature, usually sinusoidal, and are sent from transmitters to a load which could be another integrated circuit or often an antenna so that wireless communications is effected.

Measurable Learning Outcomes

At the completion of the course, students will be able to:
    -Identify the characteristics of ideal transmission lines and transmission line circuits
    -Analyze lossless transmission line circuits with linear terminations
    -Apply the lattice diagram to determine voltage step response of lossless transmission line circuits
    -Determine steady-state response of lossless and lossy transmission line circuits with different linear terminations
    -Apply the Smith chart to analyze and design transmission line matching circuits

Schedule and Assignments

Week Dates Topics Show/Tell Homework
1 Mar 28,30, Apr 1 Motivation & Terms
   -What are we trying to do?
   -Problems caused by T-line Phenomena
   -Special uses of T-lines
   -Examples of T-lines
Traveling Waves
   -energy, velocity, linearity
Lumped vs. Distributed Circuits - Video (20:00-37:00)
   -Differentiating Lumped and Distributed Circuits
   -Phase Constant, Electrical length, vp
T-line or not - Digital World
   -Rise time versus flight time
Happy Ramadan!
T-line or not - Analog World
   -Period versus flight time
   -Element size versus wavelength
T-line Parameters
   -Lossy and Lossless models
   -Telegraphers Equation
Development of Z0 and vp - Video (2:50-36:45)
   -Z0 and vp from physical models
   -Propagation velocity and Z0 of real T-lines

O-scope Measurements (Video)
Square Wave on Spectrum Analyzer (Video)
T-line Parameter Measurements (Video)

Simple ngspice file

50 ohm coax cables
RG58 up close
Other T-lines
Coaxial connectors
Coaxial resonator

4ns, 80 ohm LC T-line spice file

Basic Relationships
Solutions: 1 2 3 4 5 6
7 8 9 10 11 12 13 14 15 16 17

Stuff to Grok
2 Apr 4,6,8 Practical Considerations Video (0:15-22:00)
   -Return Current Paths
   -Physical limits of practical T-lines
Wave Travel - Video (22:55-24:24)
Infinite Length Lines - Video (25:10-34:32)
   -Incident Wave Amplitude
   -Time and Space Relationship
Finite Length Lines - Video (34:48-48:40)
   -Open Circuit Load
   -Short Circuit Load
   -Load Equal to Z0
O-Scope and Sim of open, shorted, and Z0 terminated lines
Reflections on Finite Length Lines - Video (0:08-27:30)
   -Impedance Discontinuities
   -Reflection Coefficient
Why Reflections Happen
Hardware Homework 3 (worked example)
Inductance and Loop Area (Video)
Tapped with Caps spice file
Solutions: 1 2 3 4 5 6 7 8 9 10

Stuff to Grok
3 Apr 11,13,15 Ngspice Example File
Lattice Diagrams - (Video) 00:54-38:35
Four Rho cases
Inclass Problem
Happy Good Friday/Passover!
Reactive Terminations(Video) 00:12-50:40
Reactive Termination spice file
Ngspice walkthrough (Video) 27:12-48:15)
Reactive Loads
Solutions: 1(a-d) 2 3

Stuff to Grok
ECE391 ngspice guide
4 Apr 18,20,22 Midterm 1
Cascaded Lines Video (07:55-50:00)
Tline Neighborhood Models
Tline Neighborhood Decoupling
Tline Neighborhood - Corners
Tline Neighborhood - Vias
Tline Neighborhood - Termination Methods
AT&T Video:Similarities of Wave Behavior (0:00 to about 15:00) (do on your own, no class)
Cascaded Lines
Solutions: 1 2 3 4 5 6
Tline Neighborhood
Solutions: 1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 spice_files

Stuff to Grok
5 Apr 25,27,29 Steady State Lines
Steady State Lines; λ/4 and λ/2 Behavior
Steady State Line Spice demo: λ/4, λ/2 Lines
Standing Waves Spice file
Midterm 2 - Reactive Terminations/Cascaded Lines
Steady State Analysis
T-Line Equations - Lossy Case
dB and Nepers
6 May 2,4,6 Lossy T-Lines; Velocity and Dispersion
Lossy T-Lines; Practical Considerations
Happy Cinco De Mayo!
Reflections on Terminated Lines
Standing wave patterns and SWR
Finding Zmin, Zmax of Standing Waves
Quarter and Half Wave Behavior
Solutions: 1 2 3 4 5 6 7 8
Lossy Lines
Solutions: 1 2 3 4 5ab 5c 5d 5e 6 7

Stuff to Grok
7 May 9,11,13 TBA
Inclass problem solving
Impedance Transformations
Reactive Lines
Solutions: 1

Standing Waves
Solutions: 1 2 3 4 5 6 7

8 May 16,18,20 Smith Chart Motivation
Smith Chart Intro
  - Smith Chart Intro Video (0:00-29:36)
  - Smith Chart Walkaround Video (2:10-51:00)
Smith Chart Intro (cont.)
Demo: Network Analyzer: Looking at L, C, R and resonance on the Smith chart
Stuff to Grok (wk 7,8)
9 May 23,25,27 Smith Chart Examples: #1 #2, #3, #4
Series Stub Matching
Smith Chart
1 2 3

Stuff to Grok
Final Project   -final_shunt.sp
10 May 30, Jun 1,3 Memorial Day - No class
Quarter Wave Matching
  - Quarterwave Matching Video
Shunt Stub Matching
  - Shunt Stub Matching Video
Shunt Stub Full Example
Final Exam Review
old midterms
Finals Wk. June 7 Final exam
2-3:50pm Tuesday
LPSC 125