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 The information provided may be out of date.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.

How can I calculate absolute value of scattered power

Please login with a confirmed email address before reporting spam

Hi,

I just posted one question about this. However, perhaps the post is not clear enough.

All I want to do is to calculate the absolute value of scattered power, through far field obtained with far-field postprocessing. This should be a standard problem. However, I really don't figure out how COMSOL gives a constant (with respect to distance) value for far field, which should depend on distance.

Does any body know about this issue? Thanks!

2 Replies Last Post Feb 20, 2012, 8:06 p.m. EST
Robert Koslover Certified Consultant

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Feb 20, 2012, 3:40 p.m. EST
First of all, if all you want is the *total* scattered (or radiated) power (again that's total power, not some particular power density), then you really shouldn't use the far-field routines at all. Just integrate the normal component of power density over a surface that surrounds your radiating (or scattering) object.

Now, if you want to better understand how to interpret or manage far-field power patterns and gain in terms of power density, you will likely find the following post of interest:
www.comsol.com/community/forums/general/thread/20515/
See also: www.comsol.com/community/exchange/192/
First of all, if all you want is the *total* scattered (or radiated) power (again that's total power, not some particular power density), then you really shouldn't use the far-field routines at all. Just integrate the normal component of power density over a surface that surrounds your radiating (or scattering) object. Now, if you want to better understand how to interpret or manage far-field power patterns and gain in terms of power density, you will likely find the following post of interest: http://www.comsol.com/community/forums/general/thread/20515/ See also: http://www.comsol.com/community/exchange/192/

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Feb 20, 2012, 8:06 p.m. EST
Hi, Robert!

Thanks so much for your reply!

It really helps. Now I think far field is not necessary for my case. But as for the particular way COMSOL treats far field, it is nice to read your classic post.
Hi, Robert! Thanks so much for your reply! It really helps. Now I think far field is not necessary for my case. But as for the particular way COMSOL treats far field, it is nice to read your classic post.

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.