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SAR simulation using cst

 
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kyg



Joined: 06 Dec 2007
Posts: 76
Post31 Mar 2008 17:08   SAR simulation using cst
anyone know how to simulate our antenna with SAR in cst
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shahid78



Joined: 29 Jul 2006
Posts: 199
Helped: 17
Post01 Apr 2008 18:38   Re: SAR simulation using cst
hi

if i understand you correctly you are interesting the SAR values of your antenna

well you need to model the antenna along with the body model .

you need to define the power loss monitor at the desired frequency before running the time domain solver.

at the end of the simulation you can calculate SAR from the results manu

regards
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kyg



Joined: 06 Dec 2007
Posts: 76
Post04 Apr 2008 2:07   Re: SAR simulation using cst
if already setting the monitor what is the right command
it is like this loss(f=0.47)[1](10g) as example?
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shahid78



Joined: 29 Jul 2006
Posts: 199
Helped: 17
Post04 Apr 2008 15:21   Re: SAR simulation using cst
well it depends whether you need 1g or 10g SAR value?
if you are interested in 10g SAR at f=0.47 then you should select this f=0.47)[1](10g).

regards
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kyg



Joined: 06 Dec 2007
Posts: 76
Post04 Apr 2008 18:11   Re: SAR simulation using cst
thanks shahid.......

i already try put the command like that, after setting power loss density and run the
simulation, however it still cannot calculate SAR from the results

can u tell me step by step or give some notes to setting the right way to solve this
problem:cry:
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shahid78



Joined: 29 Jul 2006
Posts: 199
Helped: 17
Post06 Apr 2008 14:20   Re: SAR simulation using cst
i think you have not set the mass density for the material inside which SAR is to be analyzed

regards
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kyg



Joined: 06 Dec 2007
Posts: 76
Post07 Apr 2008 17:10   SAR simulation using cst
mass density for material could u please explain detail
each material that i used must be set mass density but how to setting? i dunno how to do
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shahid78



Joined: 29 Jul 2006
Posts: 199
Helped: 17
Post08 Apr 2008 11:56   Re: SAR simulation using cst
well when you assign any material to your modeled structure you assign properties to it like permitivity , permeability and conductivity etc

there will be density as well when material properties window is open so just fill in the density for the SAR simulated material

regards
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kyg



Joined: 06 Dec 2007
Posts: 76
Post10 Apr 2008 18:07   SAR simulation using cst
thanks shahid.... i already can run the simulation
and i am using the phantom head model. after run the simulation and SAR calculation i find the result for the SAR. do u know about the relationship SAR and our antenna design because i am new for SAR
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shahid78



Joined: 29 Jul 2006
Posts: 199
Helped: 17
Post11 Apr 2008 10:49   Re: SAR simulation using cst
well i dont think so there is any fefinite relationship between antenna design and SAR.

but an antenna design without ground plane will definitely increase the SAR value as compard to grounded antenna design

regards
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kyg



Joined: 06 Dec 2007
Posts: 76
Post12 Apr 2008 16:18   Re: SAR simulation using cst
shahid i get the result for SAR but i donno what the result showed

Sorry, but you need login in to view this attachment
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shahid78



Joined: 29 Jul 2006
Posts: 199
Helped: 17
Post14 Apr 2008 13:36   Re: SAR simulation using cst
well if you see there is one entry which is saying

maximum SAR(rms,10g) [W/kg]=0.7022


this is your required result. as maximum 10g SAR should be less then 2
so your antenna is satisfying that criteria

regards
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kyg



Joined: 06 Dec 2007
Posts: 76
Post14 Apr 2008 19:51   SAR simulation using cst
what the benefit that 10g SAR less than 2 means?
the S11 for that antenna i get is -37.56dB and after implement this antenna with SAR the S11 is -12.75dB do u know why?
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shahid78



Joined: 29 Jul 2006
Posts: 199
Helped: 17
Post15 Apr 2008 14:46   Re: SAR simulation using cst
well SAR is a comrehensive topic so you need to do some searhing on it but as far as your question is concerned there is world wide regulation on SAR level and every new mobile handset launched into the market has to meet SAR criteria

now for 10g SAR should be less then 2 so regulatory authority will have no objection to it

regarding ur S11 results well when u place ur antenna close to human body its input impedane changes so its matching is deteriorating as compared to free space thats why ur S11 results are not good with body
i hope i answer ur question

regards
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smnobo



Joined: 13 Nov 2005
Posts: 17
Post27 Sep 2008 15:05   Re: SAR simulation using cst
Hi dear Shahid,
please i'm trying to calculate the SAR values by using CST. i obtain the 3D results but i dont know how can i plot the SAR values versus to the distance (cartesian: SAR-values in Y-axis and Distance (mm) in X-axis).""D is the distance that separe the antenna to all points on X-axis into the human head model )
thanks for your help that you give on this forum.
best regards.
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shahid78



Joined: 29 Jul 2006
Posts: 199
Helped: 17
Post30 Sep 2008 13:47   Re: SAR simulation using cst
hi

you need to define a line along which you are interested in finding the SAR values.
then go to postprocessing and request for SAR values along the curve

i hope this answers your question


regards
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smnobo



Joined: 13 Nov 2005
Posts: 17
Post01 Oct 2008 4:08   Re: SAR simulation using cst
Dear shahid thank you very much for your answer. it's good now.
please can you tell me about the technics used to reduce and minimize the SAR (if you have somme article please to send it to me, or post it here).my e-mail: simotic(at)yahoo.fr
i'm grateful for your help, thanks
Best regards
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*maxim*



Joined: 25 Sep 2008
Posts: 6
Post14 Oct 2008 3:23   Re: SAR simulation using cst
Dear shahid

i'm doing reduction of SAR using metamaterial.
do u hav any idea on metamaterials??
i would to hav some articles relating to SAR too..
email: sueling_capri(at)hotmail.com
thanx a lot.

rgds.
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shahid78



Joined: 29 Jul 2006
Posts: 199
Helped: 17
Post17 Oct 2008 12:23   Re: SAR simulation using cst
hi

well to reduce SAR you need to reduce the backward radiation from the antenna.
now there are different techniques to reduce the backward radiation . if you search google i hope u will find lot of material

regarding metamaterial well you can use metamaterial (which are engineered materials having interested electromagnetic feature) to reduce SAR as they have frequency bandgaps for propagation of surface waves which are responsible for backward radiation
i hope this might give you some clue to your questions

regards
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