rf amplifiers stability network

[tsp]

Hi,

I was simulating a RF amplifier and I found out that by using a
feedback stabilization network, the input reflection coeffecient is
lowered. (At the moment I do not have any matching networks, I am
simply seeing what the S-parameters are?) Why is that? Does
anybody know?

Thanks,
tspjor

 

[Joerg]

This is because you are physically connecting something to the input
that wasn't there before, and its effect is magnified by the gain. The
first couple pages of this doc may help:

http://web.mit.edu/klund/www/papers/jmiller.pdf

Read on though, it has an interesting copy attached to it from the
roaring 20's...

Regards, Joerg.