RadioBanter - View Single Post - Re-Normalizing the Smith Chart (Changing the SWR into thesame...

August 19th 03, 07:10 PM

(Richard Harrison) wrote in message ...
Dr. Slick wrote:
"Therefore, the reflected voltage can never be greater than the input
voltage for a passive network, and the reflection coefficient can never
be greater than 1 for such a case."

Terman, despite Reg`s disdain for experts, seems to agree with Dr.
Slick. Here is Terman`s gist:
1. The reflected wave is identical to the incident wave except it
travels toward the generator.
2. Ereflected / I reflected = -Zo. Just as Eforward / I forward = Zo

Thank you Richard! You and Richard Clark should be named twin
pillars of reason in a sea of irrationality spurred by the Lust of
Always Being Right.

This is a very important point, that the reflected voltage will
be received by the same impedance that launched it to begin with.

3. Line loss causes the reflected wave to decline as it travels toward
the generator.
4. Phase of the reflected wave drops back as distance back from the load
increases.
5. Volts at the load are the sum of the incident and reflected wave
volts. Likewise for currents.
6. E/I at the load equals Zload.
7. The vector ratio Ereflected / E incident erquals rho, the reflection
coefficient..
8. In a lossless line, rho is the same everywhere on the line.
9. The effect of a reactive load is merely to displace the SWR pattern
on a transmission line.
There is no opportunity in the stated conditions on a transmission line
for a reflected voltage to exceed the incident voltage or for the
reflection coefficient to exceed one (1).

Best regards, Richard Harrison, KB5WZI

It's really an elegant and simple equation:

[s11]**2 + [s21]**2 = 1

For a lossless passive two port network, where the brackets
indicate magnitude only. If the sum of the squares is less than one,
the network has losses.

Slick