Novel fast SAR methods for compliance testing of wireless devices

The current standardized SAR evaluation technique is optimized with respect to the requirements of maximal repeatability and minimal measurement uncertainty. The uncertainty satisfies the requirement of being independent of the source and source-phantom coupling mechanism. These requirements are best achieved by the current SAR evaluation technique that is adaptive and based on 3D scanning of the induced field inside a homogeneously-filled phantom with a single miniaturized isotropic probe. However, such an evaluation is time consuming, i.e., greater than 10 minutes per scan. Due to an increased demand for faster evaluation methods, novel techniques have recently been proposed and implemented for reconstructing the 3D SAR pattern based on sensor arrays, intelligent scanning protocols or combinations of both. The evaluation can be reduced to less than 1s for array systems and to less than two minutes for intelligent scanning. We compared the performance of 35 commercial phones for two array-system implementations. We will discuss the advantages and limitations/shortcomings of each of the novel fast SAR methods for the compliance testing of wireless devices.