With the development of science and technology, the current wireless communication equipment will have multiple antennas and transmitters. For SAR testing of multi-antenna simultaneous transmissions, CE and FCC give their respective test solutions.

The CE standard EN 62209-2: 2010 specifies alternative evaluation methods for four multi-antenna simultaneous launchers. Spatial mean SAR value peak sum, select the maximum spatial mean SAR peak, volume interpolation extrapolation method and volume scanning method. (EN 62209-1: 2016 also added multi-launch assessment content)

(1) the method of spatial mean SAR value is always the most conservative method, and we are the most commonly used reference method for CE emission evaluation.

(2) The method of selecting the maximum spatial mean SAR peak is the most risky method, and each hot spot is far and has an accurate assessment of no more than 5% interaction.

(3) volume interpolation extrapolation method, is a precise and fast method, always applicable.

(4) Volume scanning is the most accurate method of assessment and is always applicable. But the time required is too long. When the distance between the two hot spots is close, the volume scan synthesis value is close to the value of the spatial mean SAR value.

FCC for multi-launch assessment method more detailed. A single emission assessment is also required prior to evaluating multiple launches. In KDB 447498 D01, the principle of the SAR test for single-shot and multi-launch modes is specified and the test scheme