Difference between measuring radiated power and S11

[volker_muehlhaus]

volker,
As vfone pointed out above, S21 when using a reference antenna in real measurement, should be proportional to radiated power.

Yes, but you have to integrate over all directions (complete sphere) to get the total radiated power.

---------- Post added at 22:17 ---------- Previous post was at 22:14 ----------

Search for SAM phantom head and HSL-900 & HSL1800 for recipe and pictures. It do also exists standard hands, torso or full body.

Here is an example:
SPEAG offers phantoms, probes and automated test systems as well as software.
**broken link removed**

 

[FvM]

As vfone pointed out above, S21 when using a reference antenna in real measurement, should be proportional to radiated power.

The special problem is, that the adjacent objects are also changing the antenna's directional characteristic. So it may be misleading to assume S21 measured in a particular axis as representative value for the total radiated power.

Thanks to E Kafeman for detailed explanation of SAR measurement methods.