Error 0 / Error 30299 with microstrip Ports

Altair Forum User

I want to evaluate the near and far field of a qi Transmitter coil. The geometry was built in EAGLE and importetd using GERBER. When placing the microstrip ports at the beginning and the end of the coil, the vaidation runs with no errors, but the solver says the following Error message

 

ERROR 0 output requested in line 35 of the file Qi_A32_Coil_FR4.pre: The mesh instance of port 'Port2' is completely inside a metal entity

ERROR 0 output requested in line 36 of the file Qi_A32_Coil_FR4.pre: The mesh elements were removed and the port is therefore invalid

ERROR 30299 in line 37 of the file Qi_A32_Coil_FR4.pre: Termination due to user request (EXIT statement)

 

I reduced the mesh size at the ports to a minimum. The attached File is the Coil with a FR4 Substrate below.

Unable to find an attachment - read this blog

JIF

Hello goudakaes

 

I had a look at the model. For some reason the face in that model has strange properties (not something that you can change) that cause the mesher to think the face is in a PEC region instead of free space. I have never seen a bug like this. If possible, could you provide me with the Gerber file so that I can log a bug report. Unfortunately the model does not really help, since we need to figure out how the model ended up in this strange state.

 

I did find a workaround to get the face corrected. I created a rectangle in the same plane as the spiral, that is larger than the spiral. If you then union these two objects and delete the outer face, the resulting face seems to be correct.

 

Regarding the model and what you are trying to solve, I have the following comments:

 - 125 kHz is a really low frequency for FEKO to solve. FEKO does have low frequency stabilisation (an option that you need to activate) that can work down to sub-Hz, but it only supports PEC structures (no dielectrics allowed).

 - I noticed that there seems to be an offset (translation) that you added to raise the dielectric cube from the ground and that the spiral was not unioned with the substrate. You need to union to ensure correct meshing and connectivity and I don't think the offset should be used.

 - If this model needs to be simulated at a higher frequency (since 125 kHz is too low for FEKO given the use of a substrate), I would recommend that you change the model in one of the following ways:
 A ) Remove the finite dielectric substrate and model it as an infinite dielectric substrate (planar multi-layer substrate). You can then use the microstrip ports that you already have.

 B ) Use the finite substrate, but then add metal strips down to the ground and add an edge port (not microstrip) inside the dielectric substrate (not on the boundary).