The URC model is derived from a model proposed by L. Gertzberrg in 1974. The model is accomplished by a subcicuit type expansion of the URC line into a network of lumped RC segments with internally generated nodes. The RC segments are in a geometric progression, increasing toward the middle of the URC line, with K as a proportionality constant.

The URC line is made up strictly of resistor and capacitor segments unless the ISPERL parameter is given a non-zero value, in which case the capacitors are replaced with reverse biased diodes with a zero-bias junction capacitance equivalent to the capacitance replaced, and with a saturation current of ISPERL amps per meter of transmission line and an optional series resistance equivalent to RSPERL ohms per meter.

The number of lumped segments used, if not specified, is determined by the following formula:


Parameter Description Units
L length of the RC line in meters meters  
N number of lumped segments to use in modelling the RC line    
K Propagation Constant   2
FMAX Maximum Frequency of interest Hz 1.0G
RPERL Resistance per unit length Ω/m 1000
CPERL Capacitance per unit length F/m 1.0e-15
ISPERL Saturation Current per unit length A/m 0
RSPERL Diode Resistance per unit length Ω/m 0

See also

Lossy Transmission Lines
Lossless Transmission Lines