Reg Edwards wrote:
Cecil and others, even authors of books, have said -
- - - - |rho|^2 cannot be greater than 1.0 - - - -

Would you change your minds if I describe a
reflection-coefficient bridge, which anybody can
construct, which accurately measures values of | rho |
up to its greatest possible value in transmission lines
of 2.414 There's no catch!

Note that I didn't say |rho| couldn't be greater than one.
I said |rho|^2, the power reflection coefficient, cannot
be greater than 1.0 for a passive load, i.e. you cannot
get more power out of a passive load than you put into it.
It follows that the conservation of energy principle will
not allow the square of rho to be the power reflection
coefficient if rho is greater than 1.0.

For some reason Dr Slick has remained silent to my
acceptance of his challenge to find such an instrument.
Perhaps he's gone away to think about it.

There is an answer here. I suspect you can answer it by
answering the following question about s-parameters.
Consider the following example:

Source--50 ohm feedline--+--1/2WL 150 ohm feedline--50 ohm load

s11 is 0.5 but rho, on the 50 ohm feedline, is zero.

|s11|^2 is defined in the HP AN 95-1 Ap note as the ratio of
the "Power reflected from the network input" to the "Power
incident on the network input" Assuming we have 100 watts of
power incident on the network input, the power reflected from
the network input would have to be 25 watts. But the actual
reflected power on the 50 ohm feedline measures to be zero
watts. Hint: |s12|^2 must also be taken into account.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----