Uniform lumped port should be placed between two conductive boundaries

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Hello,

I'm designing electrodes for a component, with one end connected to voltage and the other end connected to ground.I got the error while program computing.

Uniform lumped port should be placed between two conductive boundaries

I have found some similar discussion to try to fix but it still failed. Could you kindly explain to me what I am doing wrong?

best regard



3 Replies Last Post Oct 18, 2024, 9:27 a.m. EDT

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Posted: 3 weeks ago Oct 10, 2024, 9:24 a.m. EDT
Updated: 3 weeks ago Oct 10, 2024, 9:26 a.m. EDT

Hello,

Your file show the lumped ports are floating. You also do not have an established return path, is this supposed to be on the bottom side? For any portion of your traces you should consider using the impedance boundary condition to model these. This way you do not have to create very thin thicknesses that are hard to mesh. The IBC will help.

There are links to a couple example files below on the site here that may help you but may not apply directly to your problem. Check out as many examples as possible.

https://www.comsol.com/model/coplanar-waveguide-bandpass-filter-12099

https://www.comsol.com/model/modeling-of-a-grounded-cpw-using-numeric-tem-ports-102191

Hello, Your file show the lumped ports are floating. You also do not have an established return path, is this supposed to be on the bottom side? For any portion of your traces you should consider using the impedance boundary condition to model these. This way you do not have to create very thin thicknesses that are hard to mesh. The IBC will help. There are links to a couple example files below on the site here that may help you but may not apply directly to your problem. Check out as many examples as possible. https://www.comsol.com/model/coplanar-waveguide-bandpass-filter-12099 https://www.comsol.com/model/modeling-of-a-grounded-cpw-using-numeric-tem-ports-102191

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Posted: 2 weeks ago Oct 18, 2024, 2:01 a.m. EDT
Updated: 2 weeks ago Oct 18, 2024, 2:02 a.m. EDT

Hi

Thank you for your response. Regarding the Lump ported being floating, in the example of a coplanar waveguide bandpass filter, isn't the Lump ported considered floating?

What's "an established return path"? In the signal path from the left end through the silver material area to the right end, besides the IBC (Impedance Boundary Condition), are there any other settings needed in between?

Hi Thank you for your response. Regarding the Lump ported being floating, in the example of a coplanar waveguide bandpass filter, isn't the Lump ported considered floating? What's "an established return path"? In the signal path from the left end through the silver material area to the right end, besides the IBC (Impedance Boundary Condition), are there any other settings needed in between?

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Posted: 2 weeks ago Oct 18, 2024, 9:27 a.m. EDT

Hello,

In the bandpass file you are referring to, the excitation setup is using two lumped ports but they do apply uniform elements at a couple boundaries (looks to be a differential setup). The original file I have of yours just uses two lumped ports, it does not use uniform elements. In the bandpass file there is a PEC2 boundary which represents traces on the substrate. The ports are applied between two traces. The ports are required to be in-between two conductors, which this meets. If using a regular lumped port then being at a return path would be necessary for one of the conductors. A feedline would be the other. In the bandpass simulation, physics default PEC1 there is boundary 8 which is a return path (as well as the airbox sides). I mentioned that my suggestions may be helpful but do not necessarily apply exactly. There are many examples to learn from.

Hello, In the bandpass file you are referring to, the excitation setup is using two lumped ports but they do apply uniform elements at a couple boundaries (looks to be a differential setup). The original file I have of yours just uses two lumped ports, it does not use uniform elements. In the bandpass file there is a PEC2 boundary which represents traces on the substrate. The ports are applied between two traces. The ports are required to be in-between two conductors, which this meets. If using a regular lumped port then being at a return path would be necessary for one of the conductors. A feedline would be the other. In the bandpass simulation, physics default PEC1 there is boundary 8 which is a return path (as well as the airbox sides). I mentioned that my suggestions may be helpful but do not necessarily apply exactly. There are many examples to learn from.

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