Input power in pss simulation

Hi,
I am running a pss simulation on a few transistors which should act as
a PA.

Ive defined 2 ports at the input and output.

Pin is the power out defined in port 1 under Amplitude (dBm), and the
input wave is a sine at 1 frequency. there are no other tones defined
in the port.

The pss simulation is defined as 1 pss 2.4G 3 -40 0 Large Port1

I am sweeping the input power(Pin) out of port 1 over a some range so,
when i plot the power out of port 1 vs the swept variable it should be
a straight line with a slope of 1.


BUT...

The output power of port 1 is at least 5 dBm higher than the input
power and it has spectral components. I assumed that it might be
modeling spectral regrowth which takes care of the spectral components
but not the higher power.

so when i plot the 1dB compression point i am wondering if the input
power is 5dBm higher than it says.

Secondly is the input power 1/2 VxI* like it is at the output or does
it assume equal impedances for the source and the input so something
like Pav= V^2/(4*Rport)?



also i am using a MOS transistors and the S11 of the device seems
outrageous for my device size (pretty large W/L = 320).

gamma is about 1 at about and the angle is -30 approximately.

Has anyone else seen results like this?

Thanks
Travis