In this post and more subsequent posts, I will describe the working principals of Blumlein pulse power generator. To understand working principles of Blumlein, it would be better to study pulse propagation principles in a single transmission line. following figure shows a single transmission line in which a matched load is connected to the transmission line through a switch.
The output switch is just
closed at t=0, line charged to Vc, but the load feels Vc/2 because negative pulse starts to move toward
the input end exactly after the moment in which switch S is on.
Commutating switch is
turned on at t=0 and the wave with the voltage of Vs/2 and a velocity vp propagates into the load side of
the line. The whole wave would be reflected if the source impedance were much
higher than that of transmission line. Reflection coefficient is equal to 1.
At t=L/vp,
negative pulse reflects off of generator with reflection coefficient of 1 and
then return to the load.
The pulse reach to the output end at t=2L/vp whereas the load felt a pulse of length 2L/vp,
at voltage Vc.
Finally the waveform of the
output voltage that is a square pulse of width 2T0 can be illustrated as follow.
In the next post i will discuss about the Blumlein line which is consists of two transmission line connected in series.
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