Andrew Beckett
Senior Fellow
Offline
Life, don't talk to me about Life...
Posts: 1742
Bracknell, UK
|
You should use pnoise with a probe as the output, pointing at the port. The whole point is that the port is part of the measurement equipment (think of how you'd do the measurement on the bench), and so the noise produced by the termination is not part of the noise in the circuit.
Similarly, the noise produced by the input port is at whatever temperature is set on the port via the noisetemp parameter - rather than what the simulation temperature is. That's because the input port is not on the chip, and so wouldn't be at the same temperature as the chip - it should be producing a known amount of noise..
Using a voltage as the output for pnoise is fine if you are computing noise figure, and there's nothing in the circuit which represents the loading of the "probe" - maybe you have a voltage rather than power output. It's also OK if you're not computing noise figure, but (say) output noise.
Not really a design issue - would have made more sense in the RF simulation board.
Hope that helps,
Regards,
Andrew.
|