Method for Monitoring Safety in Parallel Transmission Systems Based on Channel-Dependent Average Powers

Nicolas Boulant¹, Martijn Cloos¹, Michel Luong², Guillaume Ferrand², Christopher Wiggins¹, Alexis Amadon¹

We present a method for SAR monitoring based only on the average power for each channel of a Tx array. The corresponding SAR estimation still is conservative in the sense that all phase information is ignored. Given the simplicity of the technique, it is readily implementable on a lot of systems and does not require real-time amplitude monitoring of the RF waveform. It is shown that the cost in SAR using that technique is mild compared to the SAR result that would be obtained if the true RF amplitude waveforms were taken into account.