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I cannot understand a result about basic electromagnetics...

Posted 24 déc. 2010, 00:10 UTC−5 RF & Microwave Engineering Version 4.1 3 Replies

Sungsik Kim
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Dear all.

I just start studying COMSOL, and it is very easy simulation, but the result isn't what I wantted. What's wrong with me?
I started with 2D scattered TE wave module. The geometry is attatched as a file. The top layer is a PML, 2nd is a layer with n=1, 3rd is a layer with n=2 and the bottom layer is a PML.
Incident wave is " exp(j*k0_rfweh*y) "
The result attated says 'electric field, norm' is fluctuatiing in the region of n=2, but it's nonsense I think..
There should be only a transmitted wave in the layer with n=2 so that the norm of E field shoudm't be fluctuate.

What's wrong with me?


* I'm using ver.3.4

Attachments:

3 Replies Last Post 25 déc. 2010, 05:26 UTC−5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 24 déc. 2010, 05:04 UTC−5
Hi

I would say nothing is wrong !

if you have an electric fied (plane wave) propagating from the bottom upwards, hitting the index interface you have reflection and part of the field is coming back, hence making a standing wave, that you see nicely, but your remaining straight propagating wave is not reflected by the PML so the norm of the filed is constant

--
Good luck
Ivar
Hi I would say nothing is wrong ! if you have an electric fied (plane wave) propagating from the bottom upwards, hitting the index interface you have reflection and part of the field is coming back, hence making a standing wave, that you see nicely, but your remaining straight propagating wave is not reflected by the PML so the norm of the filed is constant -- Good luck Ivar
Sungsik Kim
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Posted: 1 decade ago 24 déc. 2010, 06:46 UTC−5
Thank you for your answering!
BUT the wave is propagating from top to bottom. The incident electric field is set as exp(j*k0_rfweh*y), and this is propagating to -y direction. Also you can find from attached file that the power flow is -y direction.

What on earth the problem?!
Thank you for your answering! BUT the wave is propagating from top to bottom. The incident electric field is set as exp(j*k0_rfweh*y), and this is propagating to -y direction. Also you can find from attached file that the power flow is -y direction. What on earth the problem?!

Attachments:

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 25 déc. 2010, 05:26 UTC−5
Hi

I modelled something similar in v4.1 and it looks like a "upwards" results see attached:



--
Good luck
Ivar
Hi I modelled something similar in v4.1 and it looks like a "upwards" results see attached: -- Good luck Ivar

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