Near end coupling coeffecient problems

  • Thread starter Thread starter Trespaser5
  • Start date Start date
  • Tags Tags
    Coupling
Click For Summary
SUMMARY

The discussion focuses on calculating the near end coupling coefficient (Kne) using the formula Kne = \frac{1}{4Td}(CZo+\frac{L}{Zo}). Given values include capacitance (C) of 10pF, inductance (L) of 80nH, and characteristic impedance (Zo) of 70.7. The user calculated the time delay (Td) based on the propagation velocity formula, resulting in a coefficient of 1.64, which raises concerns about its validity as it suggests interference voltage exceeds the aggressor voltage. The issue highlights the complexities of transmission line theory in signal integrity analysis.

PREREQUISITES
  • Understanding of transmission line theory
  • Familiarity with signal integrity concepts
  • Knowledge of capacitance and inductance calculations
  • Proficiency in using formulas for propagation velocity
NEXT STEPS
  • Review transmission line modeling techniques
  • Learn about signal integrity analysis tools like HyperLynx
  • Explore the effects of coupling coefficients on circuit performance
  • Study advanced concepts in electromagnetic compatibility (EMC)
USEFUL FOR

Electrical engineers, PCB designers, and anyone involved in high-speed digital design and signal integrity analysis will benefit from this discussion.

Trespaser5
Messages
19
Reaction score
0
I have been given a formula Kne = \frac{1}{4Td}(CZo+\frac{L}{Zo})
I've been given C as 10pF and L as 80nH and Zo as 70.7.
I have calculated Td from the formula propagation velocity = 1/\sqrt{LC} and the line capacitance and inductance are 400nH and 80pF and then divided this into 0.05m the line length is given as 50mm.

The problem is I get a coeffcient of 1.64, this can't be correct as it would mean the interference voltage would be greater than the voltage being driven in the aggressor

Anyone see where I'm going wrong ?
 
Physics news on Phys.org
How about you state the problem in full. Some kind of transmission line thing?
 

Similar threads

Help with NEXT and FEXT volatage magnitudes
  • · Replies 7 ·
Replies
7
Views
2K
Three phase AC concepts and problems
  • · Replies 2 ·
Replies
2
Views
6K
Transmission Line (simple Prob)
  • · Replies 5 ·
Replies
5
Views
3K
How is Power Transported Down Cables in Electrodynamics Problems?
  • · Replies 2 ·
Replies
2
Views
7K