If you put the perfect voltage source and the source resistor into a box
and label it "Source", you have a Source whose impedance perfectly
matches the transmission line. It's a Z0-matched system.

The source impedance of my circuit is as simple as it can get. If you
can't explain how it works, it reveals a deficiency of your theory; I
can easily calculate the voltage, current, and power in any component at
any moment of time. Without requiring bouncing waves of average power.
Or a circulator.

Roy Lewallen, W7EL

Cecil Moore wrote:
Roy Lewallen wrote:

Isn't it possible to explain what happens to the "reverse power"
without a circulator?


It is certainly possible in a Z0-matched system where
zero reflected energy reaches the source and the source
is feeding its designed-for load. If no reflected energy
reaches the source, the source impedance doesn't matter,
except for efficiency, which doesn't affect the rest of
the system. A one ohm source providing 100v to a 50 ohm
load and a one megohm source providing 100v to a 50 ohm
load will result in identical external conditions when
driving a 50 ohm load.

The picture is not as clear when reflected current and
voltage are allowed to flow into the source. We usually
don't know what the source impedance is and that
certainly handicaps any analysis. Modern designers simply
resort to protection circuitry and don't worry about
the energy analysis. We do know that reflections reaching
the source are not benign.