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Dear all,
I need to import the S-matrix of a GaAs FET into CST or HFSS and connect it to a couple of cpw fed folded slot antennas. How can I do that?

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Please help, I need it urgently.

Thanks in advance.

I.

hi Ivan,

you can use the CST Design Studio to import a touchstone files of the results and run it from Design Studio - it will provide you with the s-parameters and the farfield....

aw

Thanks a lot. The only problem is I don't have CST Design Studio. I've used Ansoft Designer and HFSS so far, and I'm a beginner with CST MWS. I did the same with HFSS and Designer, but I have problems in setting boundaries with this kind of structure.
It is a unit cell of an infinite array. A vertically polarized plane wave should excite a current in the receiving folded slot. Then, the FET amplifies the excited current towards the drain. Finally, the re-transmitting orthogonal folded slot must reradiate the amplified signal, which is orthogonally polarized with respect to the incident field. I know I have to use periodic boundaries (Master-slave in HFSS, periodic in CST) and floquet ports, but results are totally unreliable, probably because of boundaries and port settings. My intention is to get a 4 port S-matrix (input free space, output free space, FET gate lumped port, FET drain lumped port) in Designer in order to get the gain (s21) of a unit cell embedded into an infinite array. Any idea of how to do that, considering both the passive structure and the active device? How to set correct boundaries and free space ports?

Thanks again.

Ivan

Hi Ivan

Please dont forget than you have to deembed the ports back to the reflectarray face, otherwise the results will look crap.

Its weird you dont have CST Design Studio, its supposed to be given free, a limited version, to anyone who buys Microwave Studio.

Hi Ivan,

yes mpero is ríght about design studio. Are you using 2006B or 2008? It should work in this case. A design studio window is always automatically created when you start an MWS project - look at the bottom of the drawing window and you will see another tab - click on it - that is the Design Studio window.

aw