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Transmission Lines

General Form:
tname n1 n2 n3 n4 [model] [param=value ...]
oname n1 n2 n3 n4 [model] [param=value ...]
Examples:
t1 1 0 2 0 z0=50 td=10ns
tw 1 0 2 0 z0=50 f=1ghz nl=.1
tx 1 0 4 0 l=9.13e-9 c=3.65e-12 len=24
ty 2 0 4 0 l=100pH c=5pf r=1.5 len=12
tz 2 0 4 0 tranmod len=12

In WRspice, the transmission line element represents a general lossy or lossless transmission line. The simple case of the lossless line of SPICE2/3 is handled in WRspice by this device. The lossy line (LTRA) device of SPICE3 is also handled by this element in WRspice, though this is not evident to the user. Additional parameters represent an extension of the SPICE2/3 element to the lossy case. The WRspice transmission line is a logical combination of the SPICE3 lossless transmission line, the SPICE3 lossy (LTRA) transmission line approach of Roychowdhury and Pederson [13], and the Pade approximation lossy line approach of Lin and Kuh [14].

Above, n1 and n2 are the nodes at port 1, n3 and n4 are the nodes at port 2. Note that this element models only one propagating mode. If all four nodes are distinct in the actual circuit, then two modes may be excited. To simulate such a situation, two transmission line elements are required.

There is a fairly lengthly list of parameters which can be applied in the device line, or in a model. If a model is referenced in the element line, the element defaults to the parameters specified in the model, though any of these parameters can be overridden for the element if given new values in the element line.



Subsections
next up previous contents index
Next: Model Level Up: Passive Element Lines Previous: Switches   Contents   Index
Stephen R. Whiteley 2006-10-23