Explanation of pictures only to the characteristic impedance

Explanation of pictures only

to the characteristic impedance of the line for et/up. Where U is the phase velocity the line looks infinitely long until the pulse has time to reach th the line. In other words, back to the input. Therefore, when the switch closes at t- load and reflect appears as a voltage divider consisting of the source impedance and the inp a impedance, both being initial voltage on the line is thus and this voltag waveform propagates toward the load with a velocity The leading edge of the pul on the line at time t z/ as shown in Figure 2.21b will be at position z The pulse reaches the load at time t/up Since the load is matched to the line, is no reflection of the pulse from the load. The circuit is now in a steady-state condition, an voltage on the line is constant: v (z. t) Vo/2 for all t e/vp. as shown in Figure 2.21 This is, of course, the DC value that we would expect for a voltage divider consisting equal source and input impedances, Next consider the transmission line circuit of Figure 2.22a, where the line is now tor minated with a short circuit. Initially, the input impedance of the line again appears as Z and the initial incident pulse again has an amplitude of Vo/2, as shown in Figure 2.22 (b) (c) FIGURE 2.21 Transient response of a transmission line terminated with a matched los (a) Transmission line circuit with a step function voltage source. Respoo for 0

Solution

VL/Vo = ZL- ZO /(ZL +ZO)

Input= V/2S

output = v/r(1-e^-t/RC )