Type Names: ltra, tra
The general transmission line model may be used in conjunction with transmission line devices, though the use is optional. The parameters that appear in the model are the same parameters that can be given on the device line (with the exception of the initial conditions). These parameters are discussed in section 2.14.9 describing the general transmission line.
Transmission line models can have either of two type names: tra or ltra. The ltra name is required to support the SPICE3 LTRA lossy transmission line model. If this name is used, the level will default to 2. This will be overridden if the level is set explicitly. If the tra keyword is used, then the level will default to 1. Otherwise, the two words are interchangeable.
The parameters provided in the model will serve as defaults to the referencing device, but can be overridden if explicitly set on the device line.