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How to set the boundary condition in the RF module

Posted Jul 3, 2012, 1:59 a.m. EDT RF & Microwave Engineering Version 3.5a 2 Replies

Qiangsheng Huang
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I use RF module -> Hybrid Mode Waves -> Mode analysis to calculation the effective index of a metal waveguide in the air. However I need an additional condition for my problem. The additional condition is the continuuity of the "normal comopent" of the electric field. I don't know how to do it.
2 Replies Last Post Jul 16, 2012, 9:33 p.m. EDT
Robert Koslover Certified Consultant
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Posted: 1 decade ago Jul 12, 2012, 1:14 p.m. EDT
I can't speak to the details of your particular model, but typically, Comsol Multiphysics will let you specify all the relevant boundary conditions. So if, for example, continuity of the normal component of electric field across a boundary is an appropriate specification, then the software will generally enforce it already or allow you to do so. Suppose, for example, that your boundary were simply a continuity condition (such as a non-physical "surface" in the middle of a problem, due to the way you built the geometry). In that case, both normal and tangential fields would automatically be continuous across it, without you having to specify that condition at all. On the other hand, if a surface were the surface of a conductor or dielectric, it would generally be a mistake to tell the software to enforce continuity of the normal component of E since, in fact, the normal component is generally discontinuous there due to the surface charge density. If this explanation doesn't help, you may need to explain in more detail the nature of your specific problem & model, so that people reading this can figure out where the issue is.
I can't speak to the details of your particular model, but typically, Comsol Multiphysics will let you specify all the relevant boundary conditions. So if, for example, continuity of the normal component of electric field across a boundary is an appropriate specification, then the software will generally enforce it already or allow you to do so. Suppose, for example, that your boundary were simply a continuity condition (such as a non-physical "surface" in the middle of a problem, due to the way you built the geometry). In that case, both normal and tangential fields would automatically be continuous across it, without you having to specify that condition at all. On the other hand, if a surface were the surface of a conductor or dielectric, it would generally be a mistake to tell the software to enforce continuity of the normal component of E since, in fact, the normal component is generally discontinuous there due to the surface charge density. If this explanation doesn't help, you may need to explain in more detail the nature of your specific problem & model, so that people reading this can figure out where the issue is.
Qiangsheng Huang
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Posted: 1 decade ago Jul 16, 2012, 9:33 p.m. EDT
Hi Robert,

Thank you for your response.

I have overcome this problem.
Hi Robert, Thank you for your response. I have overcome this problem.

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