On Jan 2, 9:59*am, Cecil Moore wrote:
Keith Dysart wrote:
Can you make this all work for a pulse, or a step
function?

I accept your "NO" and agree that EM waves are
incapable of providing solutions for pulse or
step excitation.

But why don't you just say so clearly.

Please reference a good book on optical EM waves
for a complete answer.

Given that optical EM waves are only capable of
solving a subset of the uses of transmission lines,
it is not obvious why I should study them when
I can invest in learning approaches that will do
the whole job.

It is *not me* making it work.

True. And as you have said, it does not work
for pulses or steps.

It is a body of physics knowledge that has existed
since long before you were born. It should have
been covered in your Physics 201 class. That you
are apparently unaware of such is a display of
basic ignorance of the science of EM waves.

Some who claim to have studied them thoroughly
seem to be constrained by their limitations. Is
that better?

The basic theory applies specifically to coherent
waves (which are the only EM waves capable of truly
interfering). CW RF waves are close enough to ideal
coherency that the theory works well. It would no
doubt work for a coherent Fourier series as well
but I don't want to spend the time necessary
to prove that assertion.

How do you compute
* Ptot = Ps + Pr + 2*SQRT(Ps*Pr)cos(A)
for a pulse or a step?

The above equation applies to coherent signals.
It is known not to work when the signals are not
coherent because the angle 'A' never reaches
a fixed steady-state value.

Or is your approach limited to sinusoids?

Again, it is not *my* approach and is described in any
textbook on "Optics" including Hecht and Born & Wolf.

Well, others more knowledgeable than I in optics
have disputed whether *your* approach accurately
represents those described in the textbooks.

In any case, being applicable only to sinusoids
limits the general applicability to transmission
lines which happily work at DC.

...Keith