University of Utah Introduction to Electromagnetics Lecture 13: Impedance Matching

1. University of UtahIntroduction to ElectromagneticsLecture 13: Impedance Matching Dr. Cynthia Furse University of Utah Department of Electrical and Computer Engineering www.ece.utah.edu/~cfurse 1 Abstract:Reflectometry methods including time, frequency, sequence, and spread spectrum reflectometry methods are capable of providing highly accurate location of faults on aircraft wiring. One of the significant challenges in applying these methods in practice is that many wires, particularly power wires, branch into tree-shaped networks from which multiple reflections create extremely difficult-to-interpret reflectometry responses. In this presentation, we will discuss the complexity of the branched network problem and why accurate measurements of the length and magnitude are so critical for solving this problem. We will also introduce two functional novel systematic approaches to solve this problem, which do not require prior measurements as baselines. Additionally, we will present results from our approaches with both simulated and measured reflectometry data of branched networks.Sources of error including measurement error and topology ambiguity are considered, and an assessment of network mapping strategies is given for both ideal and nonideal data.Abstract:Reflectometry methods including time, frequency, sequence, and spread spectrum reflectometry methods are capable of providing highly accurate location of faults on aircraft wiring. One of the significant challenges in applying these methods in practice is that many wires, particularly power wires, branch into tree-shaped networks from which multiple reflections create extremely difficult-to-interpret reflectometry responses. In this presentation, we will discuss the complexity of the branched network problem and why accurate measurements of the length and magnitude are so critical for solving this problem. We will also introduce two functional novel systematic approaches to solve this problem, which do not require prior measurements as baselines. Additionally, we will present results from our approaches with both simulated and measured reflectometry data of branched networks.Sources of error including measurement error and topology ambiguity are considered, and an assessment of network mapping strategies is given for both ideal and nonideal data.

2. Impedance Matching How to add parallel and series lumped elements to a circuit Single stub matching with Series or parallel stub Open or short circuited stub Matching with a quarter wave transformer 2

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5. How to add series lumped elements 5

6. Series R,L,C 6

7. How to add parallel lumped elements 7

8. Parallel R,L,C 8

9. Combination of Series & Parallel 9

10. Review Stubs (section 2.7) 10

11. Short & Open Circuited Stubs 11

12. Match the Real Part 12

13. Series Stub Match 13

14. Parallel Stub Match 14

15. More about Stubs (shortest, L,C) 15

16. Quarter Wave with complex Load 16

17. Impedance Matching How to add parallel and series lumped elements to a circuit Single stub matching with Series or parallel stub Open or short circuited stub Matching with a quarter wave transformer 17