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Reference Power in CST

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Jun 9, 2011
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My task is to calculate the SAR in a whole-body-voxel model that stands in various configurations near an electronic article surveillanc (EAS) system.
The system itself consits of 2 pylons, each with 3 wires, excited with discrete ports (i used to have current ports, but the SAR calculation where totally wrong, so I changed to S-Parameter ports).

My problem is, if I start the SAR calculation, I'm not sure what reference power i have to use. I think I should use "user defined: 1W" and pick "define accepted power as reference" in the "Special" dialog box.
But if i don't use the "Special" dialog box, and calculate the SAR value, the macro shows "6 W (RMS)" in the result window. I think the 6W means 6 ports x 1W...but I'm not sure.
I tried to calculate the SAR value manually and it seems that the version with 1W accepted power as reference is ok(Maximum SAR (rms,10g) [W/kg]: 0.022712), but on the other hand the value for the second version is also not so unbelieveable(Maximum SAR (rms,10g) [W/kg]: 0.133032).

I nearly forgot--> the frequency is 8.2 MHz, so the reference value according to ICNIRP is 0.08 W/kg, if that helps you in any case.

The ports itself have a 1 W RMS power (impedance ports), and i think that CST uses 1 W peak power for the SAR calculation, so i have to use the "accepted power as reference" option to use 1 W RMS as a reference, but I'm not sure if that is meant for 1 port (1 W for each port) or for all together (1/6 W for each port).

Summarized, the main problem is that I'm not sure how to understand the "reference power thing", if it is meant for each port (1 W accepted power - RMS for each port), or all together (6x1 W accepted power - RMS), or whatever...


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