IEEE 1528-2003 pdf download IEEE Recommended Practice for Determining the Peak Spatial-Average Specific Absorption Rate (SAR) in the Human Head from Wireless Communications Devices: Measurement Techniques
1.Overview
1.1 Scope
The scope of this recommended practice is to specify protocols for the measurement of the peak spatial-average SAR in a simplified model of the head of users of handheld radio transceivers used for personalwireless communications services and intended to be operated while held next to the ear. It applies tocontemporary and future devices with the same operational characteristics as contemporary devices thatoperate in the 300 MHz-3 GHz frequency range and provides a conservative estimate” of the peak spatial-average SAR representaive of that which would be expected to occur in the heads of a significant majorityof persons during normal use of these devices, but which may not be the absolute maximum value that couldpossibly occur under every conceivable combination of head size, head shape, handset orientation, andspacing relative to the head.
This recommended practice does not address the measurement of SAR induced in the external tissues of thehead, for example the external ear (pinna). Concepts, measurement techniques, instruments, calibrationtechniques. phantom models for SAR system validation, and limitations of systems used for measuring theradio frequency (RF) electric field strength for purposes of determining the spatial-peak mass-averagedSAR, e.g., per I g or 10 g, in simulated-tissue models, including homogeneous anatomical models of thehuman head are described. A specific anthropomorphic head model, the dielectric properties andformulations for tissue-equivalent phantom materials, and techniques for verifying the dielectric propertiesof the phantom material are provided. The relative orientations and spacing between the head model and thehandset are defined. Procedures are described for calibrating electric field (E-field) probes used for SAR measurements and evaluating measurement uncertainties associated with probe characteristics, such asisotropy, linearity, spatial resolution, boundary effects, modulation effects, offset voltage, and environmentalconditions. Procedures for assessing system uncertainties associated with calibration. probe positioning, andthe dielectric properties of the tissue-equivalent solutions are also included. Detailed suggested proceduresare provided in the annexes.
1.2 Purpose
The purpose of this recommended practice is to provide a protocol for the measurement of the peak spatial-average SAR in an anatomical model of the human head of users of wireless handsets intended to beoperated while held next to the ear. It provides users with standardized and accepted protocols and testorocedures. measurement and validation technioues. and means for estimating the overa uncertainty inorder to produce valid and repeatable data. Specific SAR limit values are not included because these aregiven in other documents,e.g..IEEE Std C951~-1999.
1.3 Background
Yarious national regulatory agencies, for example the Federal Communications Commission (FCC) in theUS, require the peak spatial-average SAR associated with certain wireless handsets to be evaluated to ensurecompliance with their rules (Code of Federal Regulations (B31] and guidelines of the FCC JB451, JB46)).The SAR values in such rules and guidelines. defined as the rate at which energy is absorbed per unit massin an object exposed to an RF field, are usually based on standards such as IEEE Std C95.1-1999 orguidelines such as those developed by the International Commission on Non-lonizing Radiation Protection[B69]麝宏主炼却
The SAR in a biological body exposed to an RF field depends on a number of factors, including tissucceometry and dielectric properties and the orientation of the body relative to the source (Chou et al. B23))Since the RF energy induced in the body is scattered and absorbed at various interfaces, the internal field andhence the SAR distribution is nonuniform. Energy coupling is complicated even further by source geometryand mutual coupling when the exposure is in the near field (Stuchly et al. B138)), e.g, exposures conditionsassociated with handheld radio transceivers (Balzano et al. (B5)). Kuster and Balzano (B91] have shown thatthe peak spatial-average SAR values associated with use of wireless handsets are mainly a function of theceometry and square of the magnitude of the RF current density distribution on the device and the geometricposition of the device relative to the head. Evaluating the SAR distributions associated with such devices isa complex task, usually accomplished by measurement techniques or numerical modeling, One means toevaluate compliance with specific SAR requirements is by measurement of the electric field strength intissue-equivalent medium using anthropomorphic models of the human head.
The current state-of-the-art regarding SAR compliance assessment utilizes anthropomorphic-shapedphantoms made of a low-permittivity, low-loss plastic or fiberglass shell filled with homogeneous tissueequivalent liquid. The phantom size and shape and the electrical properties of the tissue-equivalent liquid asaveraged to represent “head” tissue are chosen to ensure that the measured SAR values are conservative, i.e..consistently exhibit a slight overestimation compared with an equivalently shaped heterogeneous headmodel
IEEE 1528-2003 pdf download
PS:Thank you for your support!
