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A few Short Questions on HFSS

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enyxep

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deembed hfss

Hi guys, i've been using hfss for almost 2 week now but i still haven't figure out some stuff :cry: . so i'm hoping some of u could help me see through the problems :wink:
so here it is:

in defining wave port:
- What does it mean by deembed port ?

in setting up analysis setup:
-what is adaptive pass? is it the number of test iteration?

-what does delta S represents? what would normally the max value?

-what does lambda refinement do? is it the same lambda as in wavelength?

If solution doesn't converged. What does it actually mean?

Last one: How to plot 1-dimension Electric field against freq? e.g. Ex v.s freq in the result report.

that's it.. many thanks guys..

regards.
enyxep[/b]
 

hfss delta s

- What does it mean by deembed port ?
The reference planes are moved to the end of a de-embedding line which you define. You measurements are now relative to this point instead of the ports. You should not de-embed past any discontinuities.

-what is adaptive pass? is it the number of test iteration?
The mesh density is increased (or adapted) then the error in sparameters (Delta-S) between the present pass and the previous pass is computed. The premise is that increasing the mesh density should provide a more accurate answer. If there is not mush change in Delta-S then the solution must me accurate.

-what does delta S represents? what would normally the max value?
Total S-parameter error. Don't know if it's RMS or not but the default value is 0.02 which I think is 2%. Beware that the wave port solution must also be increased if you change Delta-S max or else your re-normalized (to 50 ohm) results will be more error prone.

-If solution doesn't converged. What does it actually mean?
It means that increasing the mesh density did not result in a solution (after N passes) with less than maximum Delta-S error. You need at a minimum two passes in a row with Delta-S less than the maximum error.

Note sure about the rest.
 
hfss adaptive passes did not converge

thx again madengr,
you made it clear

But anyone can enlight me with the other questions?
cheers..
 

adaptive pass in hfss

I would recommend getting a copy of some HFSS help material (an Ansoft rep should be able to help with that). That way you would avoid some of the pitfalls of using a complex tool such as HFSS. Setting up the excitations and boundary conditions are very important in insuring that you are accurately modeling a real-world situation.

For example, if you are modeling an antenna, then you may need to seed the mesh on the PMLs in order to obtain accurate far-field parameters. HFSS converges on S-parameters only.

Good luck.
 

Re: hfss delta s

this answer is Very very helpful for me! I can't repay you! But Bundle of THANKS for the answer!


madengr said:
- What does it mean by deembed port ?
The reference planes are moved to the end of a de-embedding line which you define. You measurements are now relative to this point instead of the ports. You should not de-embed past any discontinuities.

-what is adaptive pass? is it the number of test iteration?
The mesh density is increased (or adapted) then the error in sparameters (Delta-S) between the present pass and the previous pass is computed. The premise is that increasing the mesh density should provide a more accurate answer. If there is not mush change in Delta-S then the solution must me accurate.

-what does delta S represents? what would normally the max value?
Total S-parameter error. Don't know if it's RMS or not but the default value is 0.02 which I think is 2%. Beware that the wave port solution must also be increased if you change Delta-S max or else your re-normalized (to 50 ohm) results will be more error prone.

-If solution doesn't converged. What does it actually mean?
It means that increasing the mesh density did not result in a solution (after N passes) with less than maximum Delta-S error. You need at a minimum two passes in a row with Delta-S less than the maximum error.

Note sure about the rest.
Click to expand...
 
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