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S-parameter and port BC

Posted 2013年7月22日 GMT-4 14:28 RF & Microwave Engineering Version 4.2a 2 Replies

Farhad Kazemi Khosroshahi
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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 2015年8月24日 GMT-4 05:38
COMSOL Moderator

Hello Farhad Kazemi Khosroshahi

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Tianjing
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Posted: 9 years ago 2015年8月23日 GMT-4 19:19
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)
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Posted: 9 years ago 2015年8月24日 GMT-4 05:38
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

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