Menu

Discussion Forum

New Discussion
Filtern

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 The information provided may be out of date.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.

S-parameter and port BC

Posted 22.07.2013, 14:28 GMT-4 RF & Microwave Engineering Version 4.2a 2 Replies

Farhad Kazemi Khosroshahi
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi everyone
I am studying the emissivity of a surface. In order to consider higher orders of reflection or transmission, we need to add several port BCs. for example in my case I am trying to obtain the reflectivity and transmissivity for m=0,+-1,+-2,+-3 orders. in this case we need to define 14 port BC.
in this case, for example, " abs(emw.S11)^2 " gives the zero order reflectivity. But for orders higher than 2 we can not define such expression. In fact, COMSOL does not accept " abs(emw.S101)^2 " which refers to the row 10 and column 1 of the S-matrix. We can define only the following expressions:
abs(emw.S11)^2
abs(emw.S21)^2
abs(emw.S31)^2
abs(emw.S41)^2
abs(emw.S51)^2
abs(emw.S61)^2
abs(emw.S71)^2
abs(emw.S81)^2
abs(emw.S91)^2
I need to define the following expressions as well but after typing the turn to orange
abs(emw.S101)^2
abs(emw.S111)^2
abs(emw.S121)^2
abs(emw.S131)^2
abs(emw.S141)^2

does anybody knows what is going wrong?
2 Replies Last Post 24.08.2015, 05:38 GMT-4
COMSOL Moderator

Hello Farhad Kazemi Khosroshahi

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

Tianjing
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 23.08.2015, 19:19 GMT-4
Hello,
I also want to know what is going wrong. Have you woked out any approach to solve this problem?

Thank you!
Hello, I also want to know what is going wrong. Have you woked out any approach to solve this problem? Thank you!
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: 9 years ago 24.08.2015, 05:38 GMT-4
Hi

try: abs(emw.S10_1)^2

it seems that COMSOL changes notation for port 10 and above and adds un underscore "_" to distinguish the items

Check in the Equation View for your version, this is for my v.5.1.0.180

--
Good luck
Ivar
Hi try: abs(emw.S10_1)^2 it seems that COMSOL changes notation for port 10 and above and adds un underscore "_" to distinguish the items Check in the Equation View for your version, this is for my v.5.1.0.180 -- 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