[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
gEDA-user: Spice Transmission Line Simulation Question
I am using Spice 3f5, attempting to model a coax line. I am a nubie
at this. The lossless example uses two lines to model one coax. Do I
need to do this with the ltra model? It does not seem to make a
difference.
I get funny results. I use
ac dec 100 1 1000meg
plot db(v(4)/v(2))
I see what I expect up to about 18mHz and then it oscillates.
What am I doing wrong?
tomdean
RG-8/U Simulation
* Z L C V TD Rc Rs vswr f
* (uh/ft) (uf/ft) (%c) (ns/ft) (ohm/1000ft) (ohm/1000ft) (mhz)
*50 .065 24.8 82 1.24 1.2 1.1 1.43:1 2250
*51.5 .059 22.5 85
* 10 ft line
.model inner LTRA (L=.065uh C=24.8pf R=.0012 len=10)
.model outer LTRA (L=.065uh C=24.8pf R=.0011 len=10)
.subckt rg8u_10 a1 a2 a3 a4
o1 a1 a2 a3 a4 inner
*o2 a2 0 a4 0 outer
.ends
*v1 1 0 0 c pulse 0 1 1ns 0.1ns
v1 1 0 dc 0 ac 1
r1 1 2 50
r2 4 0 50
X1 2 0 4 0 rg8u_10
* ac dec 100 1 1000meg
* plot db(v(4)/v(2))
.end
_______________________________________________
geda-user mailing list
geda-user@xxxxxxxxxxxxxx
http://www.seul.org/cgi-bin/mailman/listinfo/geda-user