Impedance matching/purely resistive

[granpa]

is this true?

http://en.wikipedia.org/wiki/Impedance_mismatch


To prevent all reflections of the signal back into the source, the load (which must be totally resistive) must be matched exactly to the source impedance (which again must be totally resistive)


what if you divide the wire into 2 parts. isn't the impedance of each complex? so shouldn't there be reflection at the boundary? obviously that makes no sense. what am i missing.

 

[The Electrician]

That Wikipedia page, under "External Links", references this pdf:
http://www.ece.rutgers.edu/~orfanidi/ewa/ch12.pdf
which should help you.

 

[granpa]

ok. i get it.

each segment of wire does have exactly the same impedance at all frequencies but a load will generally not have exactly the same impedance at all frequencies.