The problem is in leaping to the conclusion that a reflection
coefficient greater than one means that more energy is coming back from
the reflection point than is incident on it. It's an easy conclusion to
reach if your math skills are inadequate to do a numerical analysis
showing the actual power or energy involved, or if you have certain
misconceptions about the meaning of "forward power" and "reverse power".
But it's an incorrect conclusion. Then, having come to the wrong
conclusion, the search is on for ways to modify the reflection
coefficient formula so that a reflection coefficient greater than one
can't happen and thereby disturb the incorrect view of energy movement.
It's simply an example of faulty logic combined with an inability to do
the math. Adler, Chu, and Fano do understand the law of conservation of
energy, and they are able to do the math.

Roy Lewallen, W7EL

Tarmo Tammaru wrote:
"Dr. Slick" wrote in message
om...

As Reg points out about the "normal" equation:


"Dear Dr Slick, it's very easy.

Take a real, long telephone line with Zo = 300 - j250 ohms at 1000 Hz.

(then use ZL=10+j250)

Magnitude of Reflection Coefficient of the load, ZL, relative to line
impedance

= ( ZL - Zo ) / ( ZL + Zo ) = 1.865 which exceeds unity,

and has an angle of -59.9 degrees.

The resulting standing waves may also be calculated.

Are you happy now ?"
---
Reg, G4FGQ



Well, I was certainly NOT happy at this revelation, and researched
it until i understood why the normal equation could incorrectly give
a R.C.1 for a passive network (impossible).


According to Adler, Chu, and Fano, "Electromagnetic Energy Transmission and
Radiatin", John Wiley, 1960, (60-10305),
when they talk about lossy lines, and say that Zo is complex in the general
case, they come up with a maximum value for the reflection coefficient of (1
+ SQRT(2)). Eq 5.14b. Remember, it is a lossy line; so, the reflected
voltage gets smaller as you move away from the load. Somebody might want to
check this out, in case I misunderstood something. BTW, the three authors
were all MIT profs.

Tam/WB2TT