I am not going to go around in circles on this. The now obsolete Motorola RF
manual is still a good source for the real world. As for the noise figure,
it is a well known fact that best NF and maximum gain do not coincide.

Tam/WB2TT
"Dr. Slick" wrote in message
om...
"Tarmo Tammaru" wrote in message
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"Dr. Slick" wrote in message
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(Tdonaly) wrote in message
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Zo doesn't have to be the coax impedance. It can be any impedance
you want. What about interstage-matching networks between FETs? Do
you think there are no reflections there? Should you attempt to match
impedances there? I would think so.

You transform the input impedance of the driven stage to the optimum
load of
the driving stage. Whether that results in a conjugate match is
completely
immaterial. Trust me, I have done it .



Oh really? Did you use MIMP? or ADS? How did you design your
interstage matching network? what did you start off with? How do you
know a conjugate match didn't matter? What transistors did you use?
Can you show us the data sheets?

Can you show us your design notes please?



As for the Zo thing, you are trying to misapply the formula.

BTW, the one place where you would think conjugate matching should
always
apply, antenna to receiver input, does not (always). Lowest noise figure
often occurs at SWRs around 1.5

Tam/WB2TT


Nope. Zo can be anything you want, especially interstage where
you usually don't have/need a 50 ohm transmission line.

Who told you about the lowest NF at a 1.5 SWR? Can you give us a
link?

Why would reflected power at the receive end benefit NF?


Slick