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Continuity Boundary Condition Inconsistency
Posted Mar 29, 2012, 10:28 a.m. EDT RF & Microwave Engineering, Mesh Version 4.2 1 Reply
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Good morning. I have been having a lot of trouble with COMSOL 4.2 RF module and I am hoping the greater COMSOL community can help me.
I am simulating a periodic grating. I am using the continuity boundary condition on the two sides and port boundary conditions for the top and bottom. Only one period is being simulated.
Under mesh, I add an edge (I choose this to be the left edge from top to bottom). I then copy each edge individually, so I have 3 copy edge blocks.
Here is the problem: when I run my simulations, periodically I will have high intensity field points at some of the mesh nodes on the periodic boundary conditions. If I were simply simulating a plane wave from port 1 to port 2 this could really be detrimental. In the past I had this when I wasn't copying the edges correctly so the edge meshes were not the same.
I compared the simulation to that in 3.5a. The 3.5a simulation does not have this problem. Does anybody have an idea of why this may be occurring and what I may be able to do to rectify it?
Thank you all for your time.
I am simulating a periodic grating. I am using the continuity boundary condition on the two sides and port boundary conditions for the top and bottom. Only one period is being simulated.
Under mesh, I add an edge (I choose this to be the left edge from top to bottom). I then copy each edge individually, so I have 3 copy edge blocks.
Here is the problem: when I run my simulations, periodically I will have high intensity field points at some of the mesh nodes on the periodic boundary conditions. If I were simply simulating a plane wave from port 1 to port 2 this could really be detrimental. In the past I had this when I wasn't copying the edges correctly so the edge meshes were not the same.
I compared the simulation to that in 3.5a. The 3.5a simulation does not have this problem. Does anybody have an idea of why this may be occurring and what I may be able to do to rectify it?
Thank you all for your time.
1 Reply Last Post Mar 29, 2012, 12:34 p.m. EDT
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Posted:
1 decade ago
If you are using Floquet BCs, then your k-vector might not be defined correctly. If you are not using them, switch to them.
I've run numerous simulations using Floquet BCs. Assuming you mesh them properly (how you described them) and put correct k-values, they always work great.
I've run numerous simulations using Floquet BCs. Assuming you mesh them properly (how you described them) and put correct k-values, they always work great.