Power coupled to higher order modes in mode converter

[mns]

In a mode converter when higher order mode is generated from fundamental dominant mode, some of the power will be coupled to to higher order mode. Is it possible to simulate and observe the amount of power coupled to higher order mode using HFSS? I am designing a TE11 to TE21 mode converter and need to see amount coupled to TE21 mode. Thanks.

 

[cwin]

Maybe I'm missing an aspect of your question but can't you simply look at the S-parameters in your simulation? To look at those you simply right click your results -> Create Modal Solution Data Report -> Rectangular Plot -> S-parameters and then look at S("secondport",3,"firstport",1) (assuming you are talking about circular waveguides b/c the fundamental mode is TE11). The names in the quotations are whatever you named your waveports.

 

[mns]

Thanks cwin; You are right, that way I'll get the S-parameter between two poerts of required modes. Now my problem is little different. Suppose a step transition in circular w/g and thus it is converting from dominant TE11, TE11* mode to TE11, TE11*, TM01, TE21 & TE21*. If I give input power of 1mW, how will be distribution of power among different modes. Actually we excite by coaxial to w/g transition.
I can plot gamma factor in HFSS, but how to get the power? Hope I am clear about my problem.

 

[PlanarMetamaterials]

I can plot gamma factor in HFSS, but how to get the power? Hope I am clear about my problem.

If extracting power from the scattering parameters isn't sufficient, you can always integrate the real component of the Poynting vector over the port surface with the field calculator.

 

[mns]

Thanks PlanarMetamaterial. I need some more details as I have not used filed calculator. Is there any reference document?

 

[moreho]

in CST, that is easy to see the amount of power of 2nd Mode...

 

[mns]

Thanks moreho, I have to try this. Is it possible to get the power coupled to 3rd, 4th and still higher order mode using CST?

 

[moreho]

thanks,
i think you can set the number of modes in a port, in port properties, then excite that port when you select all modes in transient analysis, for example.
then after simulation finished, you can see the amount of power that is coupled in higher order modes...

 

[mns]

I have used solution type as "driven modal", it gives S-parameters, neither the mode conversion details, nor actual power coupled to the higher order from fundamental one. Not sure about transient analysis.