HFSS tutorial and simulation time

[shahid78]

hfss tutorial

hi all

i have been using CST MWS for quite a while somone suggested to me that ansoft HFSS is also worth trying. so i thought of giving it a shot

i was following the tutorial which can be found over here:



i was modeling the simple dipole antenna . after i reach to the validitation check of my model, i got error saying the dipole cylinder is intersecting with the air cylinder which i created for far field calculation. in the tutorial there was no mention of this intersection. i also though that as dipole is made of PEC and the surrounding cylinder is made of air so the PEC material should take priority .
any way i performed boolean operation and didnt get that intersection error


when i started the simulation it took more than 15 mins for simulation to finish.
while the same simulation of dipole would not take more than 3mins in CST MWS.

i want to know is this normal for HFSS to take so much time for a simple simulation of dipole.

also my S parameters results were not as in the tutorial . i am getting a linear line

i dont know where i am making a mistake

i would appreciate if experienced users of HFSS comment on the questions which i explained above

many thanks

 

[rfmw]

hfss simulation

Why don't you upload your hfss file for us to see where did you go wrong? I would not worry about the time a simulation takes, but would rather be interested in the results accuracy. What I mean to say is that HFSS takes a long time, especially when you have a discrete sweep and typical simulation takes many hours rather than minutes

 

[shlomo22]

hfss farfield calculations

I don't think metal will automatically take "priority" over vacuum in HFSS. IIRC, if object X is totally inside object Y, then HFSS uses the material you assigned to object X. Typically object X is a conductor and object Y is an air box, but HFSS does not care what the two materials are. It just looks at the geometry - which one is inside the other one. If objects X and Y *partially* intersect, HFSS does not know (from the geometry) which material to use, so it gives an error.

I'm not sure exactly what boolean operation you did, but it could have been the wrong one. If you got an error in the first place which the tutorial does not mention, then presumably you did one of the tutorial steps wrong.

 

[yogeshwarr]

hfss solver file

Hi,
Please upload ur file if u need sm real solution for ur problem. In case of CST and HFSS solver techniques are entirely different if you really want to comapre the time use Frequency domain solver of CST.

 

[umcp_engineer]

hfss tutorial uploading

If you look in the HFSS full book you will find and example of a horn. They subtracted their horn from the radiation boundary so that you could develop that gap. I on the other hand have an antenna (PEC) sitting in air without any subtractions and it works fine... So really you should be good either way... may need to upload your file. Possible problems here come with the way you define your excitation...

 

[pdsuperman]

hfss simulation time

yes,just upload ur file