
109Theory of Distributed-Parameter Circuits and Impedance
remaining parts of the line on the line section, we can dene the impedance
per unit length.
It should be clear from Equation 1.239 that the line impedance is a function
of the line length x, and
Z
xZ
finite
infinite
in Equation
in Equation perunitlen
1 239
1 241
.
.<
ggth
(1.242)
Therefore, it is not possible to discuss wave propagation on a nite line by
Pollaczek’s, Carson’s, or Sunde’s formulas in Equation 1.241.
The characteristic impedance seen from an arbitrary position (distance
x from origin) is always the same on an innitely long line, as already
explained, while it cannot be dened on a ...