Multiple transmission lines

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SUMMARY

The discussion focuses on analyzing reflections in multiple transmission lines with an internal impedance of 20 ohms, connected to a source of the same impedance. The participants explore the implications of varying line lengths from 1 inch to 8 inches and the effects of sending short pulses versus continuous signals. It is established that reflections can complicate signal analysis, especially when multiple lines are connected in parallel, potentially leading to standing waves. The patent referenced (US5696667) suggests that these lines behave like a lumped capacitor and inductor, although the lack of diagrams complicates understanding.

PREREQUISITES
  • Understanding of transmission line theory
  • Knowledge of impedance matching
  • Familiarity with pulse signal analysis
  • Basic concepts of standing waves
NEXT STEPS
  • Research "Transmission Line Reflection Coefficient" for detailed analysis techniques
  • Study "Standing Wave Ratio (SWR)" to understand signal interactions
  • Explore "Lumped Element Models" in transmission line theory
  • Investigate "Velocity Factor in Transmission Lines" for accurate pulse timing
USEFUL FOR

Electrical engineers, RF engineers, and anyone involved in high-speed data transmission or signal integrity analysis will benefit from this discussion.

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If a source which has internal impedance 20 ohms is connected to multiple transmission lines of impedance somewhat equal to 20 ohms, which vary in length(maybe from 1" thru 8").
How do I analyze the reflections/draw the bounce diagrams.
According to a patent - http://www.docstoc.com/docs/5001518...rocessing-System---Patent-5696667#viewer-area
this is supposed to work. How? I can't figure out.
 
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Assuming you know the velocity factor of the lines, you could send a very short pulse and observe the returning pulse. You could then calculate the length of the line from the speed, if this is what you wanted to do.

If your signal source was continuous, then the returning pulse would interact with the later incoming waves and may form a standing wave if the line was resonant.

If you had multiple lines all connected in parallel and a continuous source, the result would be a mess of signals. A single pulse would give multiple reflections, but you would not know which of the parallel lines was responsible for each pulse.

What do you think that patent was describing? My copy of it had no diagrams, so it was difficult to see what was being described.
 
To paraphrase, the patent says, the multiple lines make the tx line like a lumped capacitor and inductor.
I don't understand how this happens.
Try pat2pdf.org to download a copy.
The patent number is 569xxx7
x=6
 
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