Hi,

I am trying to find out Psat for an amplifier. The model uses an input current source of variable magnitude and the output power is plotted with values taken from direct plot->main form

As the magnitude of the input current is increased, the output power is supposed to reach a saturation level yielding the value of Psat. For this, I am using an AC sweep, since my intention is to plot Psat at various frequencies.

I have conceptual question here: If I need to plot power at the output, I need to have both V, and I which means I need to load a resistor/some load to have the current measurement. So I used a resistor as load at the output S1 as shown in the schematic. Then the ADE uses V and I from main form to compute Pout. But the value of load resistor also determines the current drawn and output power. So does it mean that there is an appropriate load resistor that I need to use for calculation? like a matching load but I suppose that would not work over wide frequencies. Can someone suggest me if this is a correct way for figuring out Psat /any other alternate ways?

Thanks,

-Rakesh.