Field and Wave Electromagnetics 2nd Edition by David Cheng

Exercise 25

Consider a lossless transmission line of a characteristic impedance R 0 A time-harmonic voltage source of an amplitude V g and an internal impedance R g = R 0 is connected to the input terminals of the line, which is terminated with a load impedance Z L = R L + jX L Let P inc be the average incident power associated with the wave travelling in the +z-directio n.
a) Find the expression for P inc in terms of V g and R 0
b) Find the expression for the average power P L delivered to the load in terms of V g and the reflection coefficient
c) Express the ratio P L / P inc in terms of the standing-wave ratio S.
d) For V g = 100 (V), R g = R o =50 ( ), Z L =50- j25 (0) determine P inc , , S , P L.