Uncertainty assessment of SAR measurement system

With the widespread use of wireless devices, the potential harm of electromagnetic radiation from electronic devices to human health has attracted increasing attention. International standards require the evaluation of electromagnetic radiation safety of wireless devices through Specific Absorption Rate (SAR) measurements. Due to the inherent contradiction between signal coverage and radiation intensity, SAR values closely related to wireless device radiation intensity often approach the regulatory limits. To avoid misjudgment, it is essential to ensure the accuracy of the measurement system. This paper provides a comprehensive and in-depth analysis of the uncertainty associated with SAR measurements. The uncertainty of measurement results is influenced by both the stability of the tested device and the performance of the measurement system itself. Based on a thorough analysis of the measurement system validation experiments, this paper delves into the assessment of uncertainties introduced by the measurement system. As these uncertainties are independent of the device being tested, their evaluation holds more general significance, thereby establishing a solid foundation for the analysis and optimization of measurement systems.