"Cecil Moore" wrote in message
...
Henry Kolesnik wrote:
I know they work! One of my reasons for asking the question is I've
not
found any mention in the literature of where the
"attenuation/rejection/reflection/filter residue" goes.

An open 1/4WL stub detours all the associated frequency
energy into the stub and then reflects it back to the source.

a new theory! now i'll have to add the traffic theory of waves to the list.
just who posts this detour sign? so does all the energy go down to the end
of the stub and have to make a u-turn to get back? are you sure they aren't
issued a ticket for doing that?? and then again at the junction they have
to be directed back to the source, sounds like a job for robo-cop! got to
be fast to direct all those waves back and forth!

The stub causes complete destructive interference between the
forward voltage and reflected voltage at the mouth of the stub.
Since the net voltage at the mouth of the stub is zero, no
current flows into the load

oh, oh! i know this one!! but if the voltage at the mouth of the stub is
zero, how does any wave flow down into the stub? there is no voltage there
to drive it?? how does the incoming wave know to not flow past the stub
connection and get reflected instead?? doesn't that make it a virtual short
and just reflect back to the source from there?? but wait, how does the
stub get hot then?? where does the current at the end of the stub come
from?