The length of the line may be expressed in either of two forms. The transmission delay, TD, may be specified directly (as TD=10ns, for example). Alternatively, a frequency F may be given, together with NL, the normalized electrical length of the transmission line with respect to the wavelength in the line at the frequency F. If a frequency is specified but NL is omitted, 0.25 is assumed (that is, the frequency is assumed to be the quarter-wave frequency). Note that although both forms for expressing the line length are indicated as optional, one of the two must be specified.

A lossy transmission line with zero loss may be more accurate than the lossless transmission line due to implementation details.


Parameter Description Units
Z0 Characteristic impedance. Ohms  
TD Transmission delay. seconds  
F Frequency for NL. Hz  
NL Relative wavelength.   0.25
IC initial condition. Voltage and current at each of the transmission line ports. (VA,IA,VB,IB)    

See also

Lossy Transmission Lines
Uniform Distributed RC Lines