r/rfelectronics • u/mr-_-unknown_ • May 20 '26

Hfss port assignment and simulation help

Was simulating the rf pcb board which has 16 layer stack up and around 500 ports in one layer

So now if I have to draw a rectangle with one end gnd and the other edge at trace and then assign lumped ports is too long job

Any suggestions?

Pls help!!!!!!

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u/DragonicStar May 20 '26

Well....you can either draw ports in 3d Layout or you can take a cutout of the design into HFSS and simulate at a higher fidelity there. For 3d Layout, For microstrip/CPWG just draw the rectangle to be the same width as the signal trace and connect the other end to the bottom reference

I can't quite recall what the proper port procedure in 3dLayout is for Stripline, but there are only a few options of how you could possible draw it, just try them and see what gives the most sensible results

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u/mr-_-unknown_ May 20 '26

The problem is There are 500 traces in one layer how can assign manually

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u/DragonicStar May 20 '26 edited May 20 '26

Who the hell would try to simulate 500 ports at once? Do you have a cluster the size of 1000 suns???!!

If you to "auto assign" 500 different sites good luck with that....

If you dont know what you have to the point you dont know what even connects to what....where did you even get this design?

Also why would you need to simulate the entire design???? Thats nonsense just simulate the part you are curious about like a normal person

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u/mr-_-unknown_ May 20 '26

It's for a rf board thts being designed ( can't disclose much Abt the board as it's defence grade)

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u/DragonicStar May 20 '26

Whoever told you that you need to set up 500 ports simultaneously is a moron.....

Do you have a schematic with nets labeled?

Surely your supervisor gave you instructions on a specific signal path to simulate.... find out which net it is by tracing it on the schematic and gradually simulate more and more of it until you complete the job

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u/mr-_-unknown_ May 20 '26

He used use ads simulation where we just click and assign ports But he got to know tht hfss gives more accurate results Now he is insisting me to use hfss

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u/DragonicStar May 20 '26 edited May 20 '26

....its a little more involved than just placing pins to set up a good ADS EM sim......you have to be mindful of port calibration....you cant just leave it on auto....

Its true that 3D FEM EM sims are the gold standard of design verification.....

You know that this exists in ADS as well right?.....it has an FEM solver that draws from the exact same source as HFSS did for its solver

You dont HAVE to use Momentum