TC34_SC2 - SAR evaluation - numerical techniques

jafar keshvari

The scope of this document is to describe the concepts, techniques, and limitations of the finite element method (FEM) and to specify models and procedures for verification, validation and uncertainty assessment for the FEM when used for determining the peak spatial-average specific absorption rate (psSAR) in phantoms or anatomical models. It recommends and provides guidance on the modelling of wireless communication devices, and provides benchmark data for simulating the SAR in such phantoms or models. Several methods described in this standard are based on techniques specified in IEC/IEEE 62704-1:2017, which is therefore included as a normative reference. The applicable frequency range is 30 MHz to 6 GHz. This standard does not recommend specific SAR limits because these are found elsewhere (e.g. in IEEE Std C95.1 [1] or in the guidelines published by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) [2]).

This International Standard specifies protocols and test procedures for the reproducible and conservative measurement of the power density (PD) assuming incident to the head or the body by radio-frequency (RF) transmitting devices, with a defined uncertainty. The protocols and procedures apply for a significant majority of people including children during the use of hand-held and body-worn wireless communication devices. These devices may feature single or multiple transmitters or antennas, and may be operated with their radiating part(s) at distances up to 200 mm from a human head or body . This standard can be employed to evaluate PD compliance of different types of wireless communication devices used next to the ear, in front of the face, mounted on the body, combined with other RF-transmitting or non-transmitting devices or accessories (e.g. belt-clip), or embedded in garments. The overall applicable frequency range is from 6 GHz to 300 GHz.

The scope of this standard is to define the methodology for the application of the finite difference time domain (FDTD) technique when used for determining the peak spatial-average specific absorption rate (SAR) in the human body exposed to wireless communication devices with known uncertainty. It defines methods to validate the numerical model of the device under test (DUT) and to assess its uncertainty when used in SAR simulations. Moreover, it defines procedures to determine the peak spatial average SAR in a cubical volume and to validate the correct implementation of the FDTD simulation software. This document will not recommend specific SAR limits since these are found elsewhere, e.g., in the guidelines published by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) or in IEEE C95.1.

This standard specifies computational procedures for conservative, repeatable and reproducible computations of power density (PD) from radio-frequency (RF) transmitting devices incident to a human head or body, using Finite-Difference Time-Domain (FDTD) and Finite Element Methods (FEM) with a specified computational uncertainty. These protocols and procedures apply for exposure assessments of a significant majority of the population including children during the use of hand-held and body-worn RF transmitting devices. These devices may feature single or multiple transmitters or antennas, and may be operated with their radiating part(s) at distances up to 200 mm from a human head or body. This document can be employed to determine compliance with any applicable maximum PD requirements of different types of RF transmitting devices used in close proximity to the head and body, including if combined with other RF-transmitting or non-transmitting devices or accessories (e.g. belt-clip), or embedded in garments. The overall applicable frequency range of these protocols and procedures is from 6 GHz to 300 GHz. The RF transmitting device categories covered in this document include but are not limited to mobile telephones, radio transmitters in personal computers, desktop and laptop devices, and multi-band and multi-antenna devices. The procedures of this document do not apply to PD assessment of electromagnetic fields emitted or altered by devices or objects intended to be implanted in the body.

The scope of this standard is to define the methodology for the application of the finite difference time domain (FDTD) technique when used for determining the peak spatial-average specific absorption rate (SAR) in the human body exposed to wireless communication devices with known uncertainty. It defines methods to validate the numerical model of the device under test (DUT) and to assess its uncertainty when used in SAR simulations. Moreover, it defines procedures to determine the peak spatial average SAR in a cubical volume and to validate the correct implementation of the FDTD simulation software. This document will not recommend specific SAR limits since these are found elsewhere, e.g., in the guidelines published by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) or in IEEE C95.1.

The project defines the concepts, techniques, benchmark phone models, validation procedures, uncertainties and limitations of the finite difference time domain (FDTD) technique when used for determining the peak spatial-average specific absorption rate (SAR) in standardized head and body phantoms exposed to the electromagnetic fields generated by wireless communication devices, in particular pre-compliance assessment of mobile phones, in the frequency range from 30 MHz to 6 GHz. It recommends and provides guidance on the numerical modelling of mobile phones and benchmark results to verify the general approach for the numerical simulations of such devices. It defines acceptable modeling requirements, guidance on meshing and test positions of the mobile phone and the phantom models. This document does not recommend specific SAR limits since these are found in other documents, e.g., IEEE C95.1-2005 and ICNIRP.