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#1 Sep 8, 2016
pcs_user
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Last seen: 1 year 4 months ago
Joined: 2016-09-08 11:46

Using TLOSSY (Transmission Line)

I’m looking for tips or examples for setting R and G in TLOSSY.

I want to simulate the frequency characteristic RG-8 coaxial cable from Belden (8214).
50 ohm; 0.065 uH/ft; 26 pF/ft; VP=78%; Delay 1.3 ns/ft; DCR: 1.2m ohm/ft.

Fri, 2016-09-09 00:05
alok
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Last seen: 1 year 3 weeks ago
Joined: 2016-05-10 23:49

You can refer the existin Tline cable model and appropriately tweak those models to match the desired specification. These models are available in library named - "tline" and it is included in your PSpice installation. You can also use PSpice parts >Search function to find various other cable models.

Here is model for your reference.

*             Z0(Ohms)  vp(%)  F1(MHz) Loss1(dB/100Ft) F2(MHz)  Loss2(dB/100Ft)
* RG8/U          52       66      100          2.2      1000            9
.model RG8/U    TRN (r={29.7952u*sqrt(2*s)} l=262.808n
+            g={0.0690831p*abs(s)}   c=97.1923p)

 

Another model is

* Subckt version uses fixed frequency, frq, to model simple lossy line
*
Here A1 is Near end hi, A2 is Near end lo, B1 is  Far end hi, B2  Far end lo

.subckt RG8/U      A1  A2  B1  B2 params: frq=100Meg len=1
.param PI2 {3.141592654*2}
.model RG8/U    TRN (r={29.7952u*sqrt(PI2*frq)} l=262.808n
+            g={0.0690831p*PI2*frq}   c=97.1923p)
t A1 A2 B1 B2 rg8/u len={len}
.ends
*$

Here in case of a lossy line, LEN is the electrical length. R, L, G, and C are the per unit length values of resistance, inductance, conductance, and capacitance, respectively.

Example: T4 1 2 3 4 LEN=1 R=.311 L=.378u G=6.27u C=67.3p

specifies a lossy line one meter long and R/L/G/C in per unit length.

You can find additional details about T Line model parameter in PSpice Reference Guide - Lossy Line section.

 

Fri, 2016-09-09 00:08
alok
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Last seen: 1 year 3 weeks ago
Joined: 2016-05-10 23:49

Here is indicate list of cable model available with PSpice. This panel is accesible from Place>PSpice Component > Search menu.

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