Txxxxxxx (n1+ n1- n2+ n2-) args
Lossless transmission line.
n1+ and n1- are the nodes at one end. n2+ and n2- are the nodes at the other end.
The parameters TD, Freq, and NL determine the length of the line. Either {\tt TD} or {\tt Freq} and {\tt NL} must be specified. If only {\tt Freq} is specified, {\tt NL} is assumed to be .25. The other will be calculated based on the one you specify. If you specify too many parameters, {\tt Freq} and {\tt NL} dominate, and a warning is issued.
Many parameters are offered. You should not specify them all.
| Parameters that always work. | |
|---|---|
| len | Length multiplier. (Default = 1) The effective length, regardless of its method of calculation is multiplied by this number. |
| Direct specification of electrical characteristics. | |
|---|---|
| z0 | Characteristic impedance. If not specified, it is calculated by sqrt(L/C). If neither z0 nor L and C are specified, the default value is 50 Ohms. |
| td | Time delay. If not specified, it will be calculated, either by nl/freq or by sqrt(L*C). |
| freq | Frequency for nl. |
| nl | Number of wavelengths at freq. |
| Physical parameters | |
|---|---|
| L | Inductance per unit length. This value is used only if z0 and td are both not specified. |
| C | Capacitance per unit length. This value is used only if z0 and td are both not specified. |
The standard probes for all basic elements are all available.
Transient time steps are limited to be no larger than the delay of the transmission line. Aside from this, there is no attempt to synchronize, because synchronization would result in a significant run speed penalty.
There is significant room for improvement, if there is demand for it.
Transmission lines are linear devices, so it would seem they would not be a factor in convergence.
Transmission lines can be used to decouple problem circuits. If a circuit is having convergence problems, sometimes inserting a short transmission line in an appropriate place can solve the problem by adding a small delay. Parts of circuits separated by transmission lines are considered to be separate circuits. Convergence problems in one part do not influence the other part.