Menu

Discussion Forum

New Discussion
Filter

Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

I cannot understand a result about basic electromagnetics...

Posted Dec 24, 2010, 12:10 a.m. EST RF & Microwave Engineering Version 4.1 3 Replies

Sungsik Kim
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

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 Dec 25, 2010, 5:26 a.m. EST
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Dec 24, 2010, 5:04 a.m. EST
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
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Dec 24, 2010, 6:46 a.m. EST
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)
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Dec 25, 2010, 5:26 a.m. EST
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

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content