How to change transistor s-parameters?

How would the s-parameters of a common source transistor (2 port network) change, if you added an inductor from the source to ground? I know a common source transistor amplifier is a two port network, but if you added a component between source and ground, wouldn't that change the s-parameters of that two port network? And how?

Thanks

Anything connected to the transistor will change s-parameters.What is your purpose ??

BigBoss said:

Anything connected to the transistor will change s-parameters.What is your purpose ??

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I want to optimise between noise, stability, and gain. So I have seen in some LNA designs (ex. ATF55143 datasheets have transmission line or inductor at the source) it might be good to use transmission line degeneration at the source, but I want to calculate and see the k stability and gain frequency response after adding the inductor or transmission line.

skatefast08 said:

I want to optimise between noise, stability, and gain. So I have seen in some LNA designs (ex. ATF55143 datasheets have transmission line or inductor at the source) it might be good to use transmission line degeneration at the source, but I want to calculate and see the k stability and gain frequency response after adding the inductor or transmission line.

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In order to all these, you have to use a RF simulator.Nobody knows what'll happen when you connect a degeneration inductor at the emitter/source.
A RF simulator-preferably Keysight ADS- is a must.

BigBoss said:

In order to all these, you have to use a RF simulator.Nobody knows what'll happen when you connect a degeneration inductor at the emitter/source.
A RF simulator-preferably Keysight ADS- is a must.

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That's true and thanks, but I don't have free trial for ADS anymore (I used my trials 3 times for 3 months already, they won't let me use it anymore) and I'm interested in designing my own... So, I'm thinking about doing trial and error, till I get the best design... I'm just wondering how you would calculate the s parameters using inductive degeneration, or even resistor and bypass at emitter/source... My guess would be that I would treat the transistor as a 3 port device?