S Parameter in spectre and ADS

[Avinash Akotkar]

Here all,
here i am simulation circuit with 3 port and in virtuoso while doing SP analysis i am getting total NF .
But if same circuit simulated in cadence then it will show NF(1), NF(2), NF(3)
can anybody tell me what is meaning of this and which value from ads for NF is correct

 

[Avinash Akotkar]

I have also simulated same circuit in goldengate with s-parameter analysis and it has given noisefigure interms of NF(1), NF(2), NF(3) .
My question is why we dont get noise figure in specter in terms of NF(1), NF(2), NF(3)

 

[morfozar]

Hello. Define in S parameters box in ADS your input and output ports (inset Noise). Then plot NF (port that you define as output).

 

[Avinash Akotkar]

thanks morfozar ...i uderstood rightnow

 

[pancho_hideboo]

See https://edadocs.software.keysight.com/display/ads2009U1/S-Parameter+Simulation+Noise+Analysis

You can see a defintion of NF(k) in Keysight ADSsim and GoldenGate.

If you use more than three ports, e.g, port1=RF, port2=IF, port3=LO, NF(2) is different from NF of Cadence Spectre.
Here you have to use resistor + vsin instead of port3=LO.