IEC/IEEE 62704-4-2020 pdf free.Determining the peak spatial-average specific absorption rate (SAR) in the human body from wireless communication devices, 30 MHz to 6 GHz – Part 4: General requirements for using the finite element method for SAR calculations.
This part of IECIIEEE 62704 describes the concepts, techniques, and limitations of the finite element method (FEM) and specifies 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.
This document does not recommend specific SAR limits because these are found elsewhere
(e.g. in IEEE Std C95.1 (1)1 or in the guidelines published by the International Commission on
Non-Ionizing Radiation Protection (ICNIRP) [2]).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 62209-1, Measurement procedure for the assessment of specific absorption rate of human exposure to radio frequency fields from hand-held and body-mounted wireless communication devices — Part 1: Devices used next to the ear (Frequency range of 300 MHz to 6 GHz)
IEC/IEEE 62704-1:2017, Determining the peak spatial-average specific absorption rate (SAR) in the human body from wireless communications devices, 30 MHz to 6 GHz — Part 1: General requirements for using the finite-difference time-domain (FDTD) method for SAR calculations
IEEE Std 1528, IEEE Recommended Practice for Determining the Peak Spatial-Average
Specific Absorption Rate (SAR) in the Human Head From Wireless Communications Devices:
Measurement Techniques
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
Multiple ways exist to solve Maxwell’s equations with FEM. Implementations can be based on field quantities or on potential quantities, and may be formulated using either the weighted residual method or the variational method [3J, [4J. The weighted residual method starts directly from the partial differential equation (PDE) of the boundary value problem, whereas the variational method starts from the variational representation of the boundary value problem. All implementations have the following in common:
a) They are based on PDEs, not on integral equations. The PDEs are derived from Maxwell’s equations augmented by proper boundary conditions in order to frame a well-defined boundary value problem on a finite computational domain.
b) The size of the computational domain is finite. Radiation towards infinity is implemented through an open boundary condition on its outer boundaries. Radiated fields outside the domain can be computed by integrating over a boundary that encloses the radiating structure.
C) After applying excitations and boundary conditions and discretizing the computational domain into a mesh, the derived POE is transformed into a matrix equation in which the matrix is large, sparse, and banded. “Large” is a consequence of having a large number of unknowns, several per element on a large mesh, “Sparse” and “banded” are consequences of the fact that all interactions are formulated as local interactions.
d) In the limit of infinitesimally small elements, the solution approaches the exact solution of the POE.
Annex A contains more information on FEM, along with references to literature and a discussion of its limitations. Clause 8 describes a set of tests is described that shall be used to determine whether a particular implementation of FEM is correct and sufficiently accurate to be used for SAR calculations.
This document refers to Nédélec elements of the first kind, which are polynomially exact up to order 0 (H0(curl) or edge elements) as lowest order; up to order 1 (H,(curl) elements) as second lowest order: and up to order 2 (H2(curl) elements) as third lowest order [51. If an implementation of the FEM is applied with one of these orders, the respective parts of the code verification shall be executed with this order.IEC/IEEE 62704-4 pdf download.