Information about Empire and its performance

I heard about Empire recently, who can tell me its difference with hfss or cst.
And which one is good at antenna simulation? thanks a lot!

Hi,

I have never worked with Empire but as far as I know and I see on their web page it is just a brute force FDTD code without any advanced features like conformal geometry approximation (PBA,TST in CST) or sub mesh. Form this point of view I would prefer other tools.


F.

but, that sale manager said empire simulate the vivaldi antenna the most accurately in the match of European microwave(I forget the true name of the match) ,is it true?
can anyone tell me which software is the best one in that match?

thanks (my English is a little poor)

Hi!

nice sales-talk . This benchmark dates back to year 2000. If you check their web page it says that they have been the "fastest" of all 3D solver but it says NOT that they are the most accurate one.
The reason why they can not say this at all is, that there have been no measurements available for the pure antenna. They only had measurements results including an SMA connector. This connector introduced additional reflections. Because of this, the simulation results from ALL 3D vendors did not agree this nicely with the measurement. I would say, that the preparation of this benchmark done my the EuMW was rather disappointing . Anyway, this was a long time ago.

If you compare the published results you see very good agreements (up to 10 GHz) between almost all simulators. Only the time domain codes supplied results up to 20 GHz. In between 10-20 GHz you see pretty good agreements between MWS and Concerto. Empire and Microstripes have slightly different results. The Empire results show many "ripples" in the S-Parameter. In time domain codes, you usually get this ripples if the "energy accuracy" is not sufficient. You can reduce the ripples by calculating to a higher energy accuracy, but this will make the calculation time longer. Since no other 3D tool did show these ripples I would suspect this. Again, these are just my conclusions. Since they are no measurement results available there is no proof for this!

Concerning the calculation time: If I remember correctly, all Time domain codes did show roughly similar calculation times (much less then 1h) for the results bellow 10 GHz. Any difference in the calculation time can be easily explained by the setting (energy accuracy, mesh e.g.). Again, I'm not sure about the results above 10 GHz because of the difference between Empire and the other tools. HFSS tools took much longer even below 10 GHz. However, since this was way back in 2000 most tools have been developed a lot.

F.

thank you ,RFSimulator, you are so good at EM simulation. I learn many knowledge from you.
thanks again!

Empires a bit more confusing.. u need to traverse many things for the thngs to get done..

Tutorials for empires.. we can have it in german version... butnot sure in english version........