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Module 4.9 Crosstalk between Transmission Lines
  • z  (cm)
    Vs  (V)
    Plot 1
    150
    100
    200
    50
    250
    0
    300
    -50
    350
    1.5
    1
    2
    0.5
    2.5
    0
CmL/CL =
LmL/LL =
TR =(ns)
up =(cm/ns)
speed of animation
Kb =       up*Kf =
  • t
    =
    0.0 ns
    z  (cm)
    V  (V)
    Plot 2
    150
    100
    200
    50
    250
    0
    300
    -50
    350
    0
    0.25
    -0.25
    0.5
    -0.5
    0.75
    -0.75
    1
    -1
    1.25
    -1.25
  • t  (ns)
    V  (V)
    Plot 3
    20
    20
    25
    15
    30
    10
    35
    5
    40
    0
    0
    0.25
    -0.25
    0.5
    -0.5
    0.75
    -0.75
    1
    -1
    1.25
    -1.25
Press "Start" to update animation.
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Introduction:

Show the near-end crosstalk (NEXT) and far-end crosstalk (FEXT) between two coupled transmission lines.

One of the lines is active with source Vs and the other is quiet.

Both lines have the same characteristic impedance of Z0 = 50 Ω and length of ℓ = 3 m.

Parameters:

CmL: the mutaul capacitance per length,in pF/m

CL: the capacitance per length,in pF/m

LmL: the mutaul inductance per length,in nH/m

LL: the inductance per length,in nH/m

TR: rise time

up: phase velocity

 Kb = 0.25*(CmL/CL+LmL/LL)

up*Kf = 0.5*(CmL/CL-LmL/LL)

Plot 1:
Source voltage Vs

Plot 2:
Blue curve: Near-end crosstalk along the quiet line t (v-z plot)

Red curve: Far-end crosstalk along the quiet line t (v-z plot)

Plot 3:
Blue curve: Near-end crosstalk at z = 0 (v-t plot)

Red curve: Far-end crosstalk at z = ℓ (v-t plot)