Electrotechnical Systems

52 Electrotechnical Systems

is called the characteristic (wave) impedance. Under R = 0

Z

L

C

c

=

(2.20)

The general equations for currents and voltages in the transmission line are

IxsA A

xx

(, ) =+

−

12

ee

γγ

(2.21)

VxsZAZA

c

x

c

x

(, ) =− +

−

12

e e

γγ

(2.22)

where

s is the Laplace transformation symbol

x is the distance from the sending line end to the considered point

then the second terms are interpreted as the incident (forward) waves I

f

, V

f

, and the

rst terms are interpreted as the reected waves I

b

, V

b

. It is worth noting that the

distance x is taken often from the receiving line end [2]; in this case, signs by γ in

(2.21), (2.22) change. If the line is loaded ...