"camelot" wrote in message
ups.com...
Hello,
I'm have "little" doubt about s-parameter simulations. My
question is very simple but I do not know if the answer is the same.
The Thevenin theorem can be applied to a s-parameter simulation?
That is, if I do a simulation using a port P1 of 50 ohm where at valley
of the generator I've connected 2 impedences, one in parallel Z1 and
one in series Z2. Supposing I obtained S11 at frequency f1. Then I
incorporate the impedence Z2 (at frequency f1) in the port 1 impedence
(using Thevenin), can I obtain the same S11 parameters for f1 fequency?

Camelot

I believe the thevenin theorem applies to s-parameter simulation provided
you assume the amplifier (generator) is perfect Class A and perfectly
stable. You need to be aware of where the load is located on the
transmission (1/4 wave? Not sure what you mean by 'valley'). See
http://www.sss-mag.com/pdf/arrl_circles.pdf