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.

PML and scattering boundary condition in v4.3

Please login with a confirmed email address before reporting spam

HI,

Is it necessary to define the outer boundaries of a PML as scattering boundary layers to obtain the losses of a leaky waveguide? In v3.5, I have defined the outer boundaries as perfect electric conductors (PEC) and still obtained the correct loss values. With v4.3, if I set the outer boundaries as PECs, I get only real valued effective index solutions and not complex ones, implying that the losses are zero.

Thanks.

3 Replies Last Post Aug 16, 2012, 8:26 a.m. EDT
Mette Marie Joergensen

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Aug 16, 2012, 5:12 a.m. EDT
Hi Sonali,

I think that comsol 4.3 in some cases only return real values by default, which is different from version 3.5. So maybe you have to turn complex output values on.

BR, Mette

Hi Sonali, I think that comsol 4.3 in some cases only return real values by default, which is different from version 3.5. So maybe you have to turn complex output values on. BR, Mette

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Aug 16, 2012, 6:56 a.m. EDT
Thanks, Mette. You are absolutely right. However, inspite of setting the option as <'complexout', 'on'>, the returned values are still real. And it seems like the losses that I get back by using the scattering boundary condition are not correct either.. I ma using the RF module to model a leaky dielectric waveguide.

Thanks.
Thanks, Mette. You are absolutely right. However, inspite of setting the option as , the returned values are still real. And it seems like the losses that I get back by using the scattering boundary condition are not correct either.. I ma using the RF module to model a leaky dielectric waveguide. Thanks.

Mette Marie Joergensen

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Aug 16, 2012, 8:26 a.m. EDT
I have not tried my model with PML yet, so I do not have an answer. But it is an important issue. If you find a solution, please post it in here.

BR, Mette
I have not tried my model with PML yet, so I do not have an answer. But it is an important issue. If you find a solution, please post it in here. BR, Mette

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.