Version 4
SHEET 1 1272 680
WIRE 128 192 -368 192
WIRE 320 192 224 192
WIRE 128 224 64 224
WIRE 288 224 224 224
WIRE -368 240 -368 192
WIRE 64 272 64 224
WIRE 64 272 -16 272
WIRE 288 272 288 224
WIRE 384 272 288 272
WIRE 64 304 64 272
WIRE 128 304 64 304
WIRE 288 304 288 272
WIRE 288 304 224 304
WIRE 128 336 64 336
WIRE 288 336 224 336
WIRE -368 368 -368 320
WIRE -16 368 -16 272
WIRE 64 368 64 336
WIRE 288 368 288 336
FLAG 64 368 0
FLAG 288 368 0
FLAG -368 368 0
FLAG -16 368 0
FLAG 320 192 0
SYMBOL tline 176 208 R0
WINDOW 0 2 -19 Bottom 2
WINDOW 3 3 20 Top 2
SYMATTR InstName T1
SYMBOL tline 176 320 R0
WINDOW 0 -1 -21 Bottom 2
WINDOW 3 0 21 Top 2
SYMATTR InstName T2
SYMATTR Value Td=30n Z0=150
SYMBOL voltage -368 224 R0
WINDOW 123 0 0 Left 2
WINDOW 39 24 132 Left 2
SYMATTR SpiceLine Rser=50
SYMATTR InstName V1
SYMATTR Value PULSE(0 1 0 1n 1n 10n)
TEXT 264 416 Left 2 !.tran 0 500n 0 1n
TEXT 0 440 Top 1 ;This example schematic is supplied for informational/educational purposes only.
TEXT -376 -200 Left 2 ;This examples illustrates the fundamental difference between a SPICE\ntransmission line element and a length of coax.  The SPICE transmission\nline element supports a single transmission line mode whereas a cable\nwill have any many modes as it has independent conductors.  A piece of\ncoax has two conductors, a central conductor and an outer shield, giving\nrise to two modes.\n \nTo model both modes of a length of coax, you will need two SPICE\ntransmission line elements.  One for the normal(differential) mode and\nthe other for the common mode.  Below, T1 is the normal mode and T2 is\nthe mode between the shield and the rest of the world.  These modes\nwith have different propagation speeds and impedances.  If both modes\nare modeled, then you can simulate a transmission line inverter.