# how to calculate a SAR ?

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#### magbach

##### Junior Member level 2
how to calculate sar

i use the FDTD méthode to simulate the E fieled in head phantom in 3D (IEEEsc34 recomendation) i use Matlab bat i dont new hox to use thise equation : SAR= sigma*E^2/ro. i think i must take acube contein 10g or 1g and calculate the SAR in every cell and sum total cube.
if any one new how to calculate : local SAR and global SAR in FDTD please help me
thanks

calculating sar

Hi there,
You can make, with a little effort the SAR calculation if you assume that there is a Point of SAR.
In this way all the Power Loss Densities (in W/cubic meters) will be easely converted to SAR (W/kg) aqccording to what you mentioed in the equation.

But in your case you have the E field so it is the same - take every mesh point and directly convert it to SAR.

The method you mentioned (avaraged 1g, 10g ...) is when you have a PLD results but not just the E field
IH

### magbach

Points: 2
calculate sar

you meene i appli the formul to the E matrix and i have SAR matrix ?
and i sum points of SAR so i have the SAR
what is PLD
what is difference between local SAR and global SAR
thans

how to calculate specific absorption rate

can u provide the code for calculating SAR using FDTD??????????
i want to see how can you calculate it???????????
if possible then plz send me at my email ravi8331@gmail.com.................

sar index calculating

hello ravi8331
i m not finish my programme in Matlab
i calculate the E filed in phamtom described by IEEEsc34 recomendation spheric phantom (3D)
this part are OK
i want calculate SAR I travel on i read the Ieee std described this
i m not finsh this part
can you send me the visible men head model plz (i ask you this in another topic)
you travel on HFSS i think
wath do you want i send you?
or wait when i finish my programme
my email : tassoki@yahoo.fr

hello ravi8331
i m not finish my programme in Matlab
i calculate the E filed in phamtom described by IEEEsc34 recomendation spheric phantom (3D)
this part are OK
i want calculate SAR I travel on i read the Ieee std described this
i m not finsh this part
can you send me the visible men head model plz (i asked you this in another topic)
you travel on HFSS i think
wath do you want i send you?
or wait when i finish my programme
my email : tassoki@yahoo.fr

this is no very difficulte you can show this article and if you want i send you many article described this

sar calculate

Hi again,

SAR and PLD values have the same meaning but in different units.
While the PLD (Power Loss Density) is more striagforward when one has dissipated power on lossy media and the SAR (Specific Absorbtion Rate) is including the Roh (ρ) conversion from m³ to Kg ( [PLD] = W/m³ and [SAR]=W/Kg using [ρ]=Kg/m³ ) - But this is more complicated; when converting to SAR values you need to avaraged the PLD over 1g, 10g or other agreed value and the integrate all (sumation).

As It seemes, if you have E field values you can come to SAR with your equation as you mentioned.

Hope it more helped you.

### magbach

Points: 2
3d sar

thanks itzihaim

how to calculate sar

hi,
I m trying to simulate a patch antenna in a disspersive inv like human body.