how measure power absorbed by an object in HFSS or FEKO?

power absorbed = power transmitted by tx antenna - power received by rx antenna

If I have two antennas, one tx and one rx, and have an object between them, how can I measure the power transmitted by tx antenna and power received by rx antenna in HFSS?

Thanks.

Power Absorbed will not be transmitted-received in general case. Tx antenna might radiate in other directions not catched by Rx antenna and so on. Probably in wave-guide configuration you might estimate absorption by subtracting received energy at far port from transmited one, but not in general case.

In FEKO you probably could see in *.out file (open in text editor ASCII *.out file) summary for each frequency like is shown in attached picture. There you can see power absorbed by dielectric bodies available in the simulation model. I am not sure, but you might have access to the same information from PostFEKO as well.

The screenshot is from EMCoS Virtual AntennaLab - Method of Moments solver similar to FEKO.

Thanks for the reply.

The equation for SAR = (σ/2ρ) |E|2 (W/kg)

Basically SAR is the amount of Energy absorbed by a dielectric body mass.

There are bunch of solvers that simulate SAR. Could you shed some light on how they do it, meaning how do they calculate the density and mass of the object? How do they calculate the E field? Is it the S11 reflected back? How do they calculate σ for the whole object which may be inhomogeneous as the human head?

Now can SAR be measured in a real life enviroment? Say I want to measure the SAR in the human head from an antenna placed 1cm away. How do I determine the σ, ρ, and E to find the measured SAR?

I would really appreciate an answer to this topic since I am basing my research on it and would like some leads.

Thank you.