- #1
MrBondx
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Homework Statement
For a lossless line:
The characteristic impedance is given by Zo=sqrt(L/C)
and the velocity of propagation by Vp =1/(sqrt(L*C))
where L and C are, respectively, the line's inductance and capacitance per metre length.
A transmission line is formed by two identical parallel tracks in a printed circuit board, as depicted in the attached FIGURE. The line has a length of 50 mm and all line terminations are of 70 Ohms. The line can be assumed to be lossless.
a) Use the following equations:
VNE = KNE[Vs(t) - Vs(t - 2td)]
KNE = (Vp / 4)[(CM * Zo) + (LM / Zo)]
VFE = KFE * l * (d / dt)[Vs(t - td)], where l is the length of the line.
KFE = 1/2[(CM * Zo) - (LM / Zo)]
to calculate the magnitude of the NEXT and FEXT voltages generated in the victim conductor when the source voltage, Vin, in the aggressor conductor is a voltage step of 2 V with a rise time of 100 ps.
[Note that the Vs voltage at the input to the aggressor conductor is
Vs = Vin[Rin / (Rin + Zo)] .]
CM and LM are, respectively, the mutual capacitance and inductance per metre length.[ mentor note: no success adding image inline; so readers must click this thumbnail to see larger image ]
Homework Equations
[/b]VNE = KNE[Vs(t) - Vs(t - 2td)]
KNE = (Vp / 4)[(CM * Zo) + (LM / Zo)]
VFE = KFE * l * (d / dt)[Vs(t - td)]
KFE = (1 / 2)[(CM * Zo) - (LM / Zo)]
The Attempt at a Solution
[/b]Calculate for Zo and Vp
Zo = 70.71
Vp =176776695.3
Then plug in numbers to find KNE
KNE = 3124970032 ( number looks massive not sure if it's right)Getting stuck on finding VNE
Not sure if t = rise time. Is Vin = 2? How do I find td?
Thanks for your help in advance.
[ mentor note: excessive bold text corrected ]
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