2.5 Reflection of DC voltage in Transmission lines
51
2.5.1.1.2 Voltage Pulse
In this section we will be looking at what happens along an open circuited line when a pulse
stimulus is applied (Figure 2.5-11). In order for this behaviour to be observed in sufficient details, the
pulse width is must be lower than the time it takes a signal to travel to the end of the line at the
speed allowed by the transmission line.
Figure 2.5-11 Open-circuited line with pulse stimulus
As in the previous case, as the switch is closed, our voltage wave starts travelling down the
line, as shown in Figure 2.5-12 and Figure 2.5-13.
Figure 2.5-12 Pulse travelling down the line
Figure 2.5-13
Pulse carries on travelling down the line
As the pulse moves down the line, current loops are formed which charge capacitors further down
the line and discharge the preceding ones thereby allowing the voltage to travel. This is shown in
Figure 2.5-14 and Figure 2.5-15.
E
Z
s
E/2
E
I
E/2
Zero
Z
s
E
E/2
I
E/2 E/2
Conquer Radio Frequency
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