From: Stefan Jahn <jahn@mw...> - 2005-04-06 06:19:58
> Hi Stefan,
> I am trying to implant HiSIM model into qucs, and developing mosfet model.
> I have a question for a model description in qucs.
> The standard mosfet model (your original mosfet model) uses 4 ports model
> to depict the behavior in RF and DC domain.
> S matrix is generated from Y matrix in your standard mosfet model.
> General mosfet models use 6 ports model (G,B,D,S,Dp,Sp) to depict its
> behavior in DC and AC domain.
> To implemant the HiSIM and/or BSIM3/4 into qucs, we must use the 6 ports
> In other hands, we must use 4 ports model to update and/or generate S
> Is this contradiction acceptable ?
The model can have as many ports as you like. The question is now if the
ports Dp and Sp are really ports the user can assign or if these are
internal nodes to the model.
> In your source code, I think that the S matrix differs from Y matirx in DC
> and AC simulation sequence
> so that contradictio is acceptable in qucs.
> Would you give me a comment for my question, please.
The matrix differs in AC and DC. But the S-parameter matrix is exactly
the AC matrix (with the transformation applied of course).