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PSpice TLOSSY Parameters

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Bob Penoyer

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Aug 24, 2010, 10:50:50 PM8/24/10
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The TLOSSY transmission line has these parameters:
LEN - Electrical length
R - Per unit length resistance
L - Per unit length inductance
G - Per unit length conductance
C - Per unit length capacitance

All of these are clear to me except G. Since there is an R, what is
the purpose of G? My guess is that G is the conductance per unit
length between the center conductor and the shield. Correct?

PSpice objects when G is 100 or more times larger than C, so it
appears that PSpice is looking for a small number, i.e., a high
resistance. That's why I reached the conclusion stated above.

Helmut Sennewald

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Aug 27, 2010, 6:33:06 PM8/27/10
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"Bob Penoyer" <b...@NOSPAMbobpenoyer.com> schrieb im Newsbeitrag
news:2p09765nt742n3vov...@4ax.com...

Hello Bob,

G is the conductance between the center wire and the shield.

Best regards,
Helmut


Jim Thompson

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Aug 27, 2010, 6:43:14 PM8/27/10
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On Tue, 24 Aug 2010 19:50:50 -0700, Bob Penoyer
<b...@NOSPAMbobpenoyer.com> wrote:

>The TLOSSY transmission line has these parameters:
>LEN - Electrical length
>R - Per unit length resistance
>L - Per unit length inductance
>G - Per unit length conductance
>C - Per unit length capacitance
>
>All of these are clear to me except G. Since there is an R, what is
>the purpose of G? My guess is that G is the conductance per unit
>length between the center conductor and the shield. Correct?

Yes.

>
>PSpice objects when G is 100 or more times larger than C, so it
>appears that PSpice is looking for a small number, i.e., a high
>resistance. That's why I reached the conclusion stated above.

The dimension of C is Farads, per unit-length

The dimension of G is mho's (reciprocal of Ohms), per unit-length

If the conductance (resistive) is more than the effective conductance
of the capacitance you'd have a pretty bad line :-)

...Jim Thompson
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Spice is like a sports car...
Performance only as good as the person behind the wheel.

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