Based on all the journals from the various study stimulations that been carried out, results indicate that RF shields reduce the SAR effectively. Full shield among various ferrite shapes and M4 among various ferrites are tested to be the most effective in reducing average E-field. This is because SAR decreases with increase in size of ferrite sheet whereas SRF increases with increase in size of ferrite sheet. Results have shown that attachment of RF shield on mobile phone not only reduces SAR in head model but also the radiated power. Moreover, the RF shielding does not degrade the antenna performance. However there is slight variation in return losses when compared with RF shielding. So the RF shielding gives an option for compliance testing of mobile phones at the design stage.
Another simulations show that a combined use of textiles with the right properties as a shield provides great possibilities for reduction of the RF eﬀects over the human body. This can be proved from the results obtained at probe 1 which estimate the amount of RF radiation below the skin layer, are showing that the average SAR level with all kinds of shielding materials is ≥ 400 % lower than in the case without shielding (in the case with both shielding materials the reduction is > 300 times in the strength of the ﬁeld). Besides, Reduction of the SAR levels in the brain tissue is also best noticed in the case of usage of both materials.
Therefore, from these studies, it is found that parameters that can affect SAR include: • Types of radio service (cellular, PCS, LMR, WLAN, etc),
• Types of modulations (CDMA, GMSK, TDMA, AMPS, etc),
• Physical orientation to person (held-to-ear, held-toface, belt-clip, lap-held, etc), • RF power level (in Watts or mW),
• Changes to transmitter, antenna (extracted/retracted) or accessories (clips, batteries, etc).
As a result, it is important to investigate, understand and monitor any potential public health impact. At the...
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