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De-embedding port

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Hi
I need to plot the phase of S parameters of a port. I'm not getting the same result for the phase plots in COMSOL and HFSS because I can't find how to de-embed the wave port in COMSOL. The phase difference caused by traveling the top of the air box to my cell changes my results. I would appreciate if you could help me with this. I'm new to using COMSOL and I don't have much proficiency.

3 Replies Last Post 2013年11月11日 GMT-5 20:48
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Hello Shiva Piltan

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Posted: 1 decade ago 2013年11月8日 GMT-5 21:14
Hi,

I was just encountering the similar issue, and ended up by manually de-embedding the S parameter to a common reference plane. Here is a reference paper on how to do it: literature.agilent.com/litweb/pdf/5980-2784EN.pdf

For the phase caused by the gap between the port and the structure, it is simply:
Sij ----> Sij*exp(2*i*k0*L), with L being the distance between the port and whichever reference plane you want, e.g. the front surface of your cell.

Leiming






Hi
I need to plot the phase of S parameters of a port. I'm not getting the same result for the phase plots in COMSOL and HFSS because I can't find how to de-embed the wave port in COMSOL. The phase difference caused by traveling the top of the air box to my cell changes my results. I would appreciate if you could help me with this. I'm new to using COMSOL and I don't have much proficiency.


Hi, I was just encountering the similar issue, and ended up by manually de-embedding the S parameter to a common reference plane. Here is a reference paper on how to do it: http://literature.agilent.com/litweb/pdf/5980-2784EN.pdf For the phase caused by the gap between the port and the structure, it is simply: Sij ----> Sij*exp(2*i*k0*L), with L being the distance between the port and whichever reference plane you want, e.g. the front surface of your cell. Leiming [QUOTE] Hi I need to plot the phase of S parameters of a port. I'm not getting the same result for the phase plots in COMSOL and HFSS because I can't find how to de-embed the wave port in COMSOL. The phase difference caused by traveling the top of the air box to my cell changes my results. I would appreciate if you could help me with this. I'm new to using COMSOL and I don't have much proficiency. [/QUOTE]

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Posted: 1 decade ago 2013年11月8日 GMT-5 21:18
Thanks a lot for your reply. I eventually ended up doing the same thing. I modified the phase in COMSOL using the formula you gave but I had to export my data to matlab and unwarp the phase to be in -180 to 180 degrees interval for my plots to make sense. Did you face that problem as well? Any other solutions for that? I appreciate your help.
Thanks a lot for your reply. I eventually ended up doing the same thing. I modified the phase in COMSOL using the formula you gave but I had to export my data to matlab and unwarp the phase to be in -180 to 180 degrees interval for my plots to make sense. Did you face that problem as well? Any other solutions for that? I appreciate your help.

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Posted: 1 decade ago 2013年11月11日 GMT-5 20:48
Not sure if this directly relates to your exact problem. Maybe you can calculate the de-embedded Sij first, then retrieve the phase information from the de-embedded S parameters with the constraint that it be in the -180 ~ 180 degree branch.
Not sure if this directly relates to your exact problem. Maybe you can calculate the de-embedded Sij first, then retrieve the phase information from the de-embedded S parameters with the constraint that it be in the -180 ~ 180 degree branch.

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