Please, help wiht HFSS 9.2

Hello Everybody!

I'm having difficulties designing a model for an spiral antenna at HFSS. I'm new to this software and I just want to make a simple model of a printed spiral with an ideal port so I can test some parameters. I will have to desing a balun later, but by the moment I just want to try a simple and ideal model, but I don't feel very confident about what I'm doing.

Could somebody tellme if this is correct? I've been looking for somekind of project as a model but I didn't find nothing. Please, let me attach the project file. Could you please helpme?

Thanks in advance and excuse a long messege :S

hi
i am a newbie, too. however, i downloaded the model.
first, the waveport is not right, i think, it should be non-existenc material at one side. second, i don't know whether the antenna has ground, i assign perf-E to ground. third, you should draw abc box to simulate the far field. finally, it is cost much time to simulate the model, i think it is because of the thin copper.
i attach the modified model here, maybe help you!
regards!

EdmundZheng said:

hi
i am a newbie, too. however, i downloaded the model.
first, the waveport is not right, i think, it should be non-existenc material at one side. second, i don't know whether the antenna has ground, i assign perf-E to ground. third, you should draw abc box to simulate the far field. finally, it is cost much time to simulate the model, i think it is because of the thin copper.
i attach the modified model here, maybe help you!
regards!

Click to expand...

Thanks a Lot EdmundZheng! First of all let me thank you for you advices
As you may have observed I'm a true newbie at HFSS
I'm downloading and trying you model, it looks really good to me (Y)
But I just wanted to make a note before continuing: The antenna has a ground as it were a microstrip-p@tch antenna. HFFS defines undefined faces as perfect conductors, this means that the face of the dielectric where the spiral is not is autoconfigurated as perfect ground conductor.
Talking about the copper thickness, do you think that it will simulate faster if it were thicker???

May we keep this topic alive so both of as and anyone how starts using HFFS may learn as much as possible from the others?
I hope so.
Again thanks a lot!

Added after 1 hours 25 minutes:

Dear Edmund:
I've been having a look at your model. I let myself make a few modifications: For example radiation surface box doesn't need to be so big, so I made it a bit smaller. You were rigth about copper thickness, I though it was 10 mic instead of 1 mic!!!
About excitations, in your file there was not information about what kind of port you used. A guy at the forum told me it was incorrect to use a lumpert or a waveport and that I must use a voltage difference. I'm not sure about this, but I'm using a voltage difference between spiral arms and I cannot measure S parameters! What do you thinks about this???

I attach the "new" model. There is nothing really new, I just fixed a few things as I told you.

hi Buqpa:

sorry for my poor English, maybe i don't understand what you said well.
firstly, you modified the radiation is right, just 0.25λ away is enough. secondly, as a matter of fact, the antenna also radiates below the finite ground, so, it should draw larger box to contain the model. however, i assigned infinite ground to save time, also, it can make perfect approximation. thirdly, in fact, you can draw rectangles instead of copper, and assign per-E or finite conductivity, it will save lots of time. finally, i think you can assign lumpport for this model. if any questions, you can mail to me. regards.
Edmund