On Thu, 24 Aug 2006 14:22:24 -0700, Jim Kelley
wrote:

Cecil Moore wrote:

How does a wave know whether to
carry energy or not depending upon its future fate?

Hi Jim,

I don't know how you can pass up all these tarnished jewels.

Energy at the speed of light has no time dimension (Lorenz law) and as
such there is no futurity. No future, no fate - presumptions aside
(or galore, depending upon the source).

Does a laser beam reflected from an ideal mirror carry any
less energy than the forward beam just because it has been
reflected?

Of course it does.

Jim, your question was:

How much energy is "in the reflected wave" without a circulator load
resistor?

and we find, after having gone down the primrose path:

Yes, in both cases the voltage reflection coefficient
at the load is 0.707 making the power reflection
coefficient = 0.5, i.e. half the power incident upon
the load is reflected.

The common finding of an unterminated circulator load would offer
reflections from that port passing back to the apparent source, the
original mismatched load. Hence, that load sees more than 0.707
(whatever) - now from two "sources."

There is one way to prevent this, but Cecil doesn't have enough
experience at the linear bench to come up with that solution.
Certainly I can anticipate his fog of vectors and SWR mechanics with 1
second transmission lines blossoming in the swamp - but a real bench
tech could whip out the solution and make it work with less effort and
certainly not have to cobble up a phonebook thick stack of Xeroxed
proofs.

Very inventive. The question was posed without a load on the
circulator, not without a circulator.

You were expecting something else? ;-)

73's
Richard Clark, KB7QHC