4-port S-parameter analysis of differential amplifier in ADS

[Faizan shafi]

I am working on designing a LNA in the V and W bands. I wanted to test few topologies that would suit my purpose. For that , I wanted to work on differential amplifiers. I want to find the gain and noise figure of my differential amplifier.

I have done the AC and DC analysis and I have attached main gain graph below.

I ham having problems regarding my S-parameter analysis.

I want to find Sdd21 and Scc21 and NFmin.

But i cant do the in ADS-


Is there anything wrong with my Sdd21 equation?
IN ADS i cannot find the option to turn on Mode= inout/out mix .

Can you spot some potential errors in my equation, schematic etc.
Thank you

 

[volker@muehlhaus]

Have a look at the "Balun4Port" element which has 2 terminals to separate differential and common mode, and 2 terminals to connect the circuit.

 

[D.A.(Tony)Stewart]

Does Port1 need a Freq= freq declaration?